NBSIR 83-2680

od for Assessing Benefits of

Airborne Noise Isolation

Requirements in Residential and

Educational Buildings

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Building Physics Division

Washington, DC 20234

February 1983

Final Report

Issued April 1983

•QC

100

U56

03-2630

1933

Prepared for: Technical Assistance Branch

fice of Noise Abatement and Control

.S. Environmental Protection Agency

ashington, DC 20460

NATIONAL BUIXAU OK STANDARDS

LIBRARY MAY 2 1983

NBSIR 83-2680

METHOD FOR ASSESSING BENEFITS OF

AIRBORNE NOISE ISOLATION

REQUIREMENTS IN RESIDENTIAL AND

EDUCATIONAL BUILDINGS

Fred F. Rudder, Jr.

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Building Physics Division

Washington, DC 20234

February 1983

Final Report

Issued April 1983

Prepared for: Technical Assistance Branch

Office of Noise Abatement and Control

U.S. Environmental Protection Agency

Washington, DC 20460

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

ABSTRACT

This report presents a method for estimating benefits accruing from

implementation of acoustical performance requirements for new buildings. The

method can be applied to a wide range of environmental noise conditions and

noise isolation requirements for building envelopes. Benefits are estimated

based upon the distribution of population with outdoor noise level and the

noise isolation provided by the building envelope. A method is described for

estimating noise isolation performance of existing construction based upon

local conditions.

Key words: acoustical design; benefit analysis; building codes; model code;

noise control; noise impact; outdoor-indoor noise isolation.

iii
PREFACE

This report Is one of two NBS research reports describing models for assessing

the cost and the benefits of implementation of noise control requirements in

building codes* The cost model is described in NBSIR 81-2366, "Method for

Assessing Costs of Noise Control Requirements in Multifamily Residential and

Educational Buildings." The research leading to the present report was con- ducted by the Building Acoustics Group in the Center for Building Technology,

National Engineering Laboratory of the National Bureau of Standards. This

research was sponsored by the U.S. Environmental Protection Agency, Office of

Noise Abatement and Control (ONAC) under Interagency Agreement No.

AD-13-F-1-507-0, "Model Building Code Benefits Study" dated February 1981.

The author is grateful to Casey Caccavari of ONAC for his encouragement and

suggestions provided throughout the research effort. Also, the author appreciates the many helpful comments made by the NBS reviewers: Simone Yanlv,

Belinda Collins, Myroslav Serbln and David Pallett. Special credit is due to

Dolores Hardy and the staff of the Word Processing Center for the many hours

of typing required to bring the report to camera-ready form.
TABLE OF CONTENTS

Page

ABSTRACT ill

PREFACE iv

1. INTRODUCTION 1 1.1 PURPOSE AND SCOPE 1 1.2 ORGANIZATION 1 2. MODEL NOISE CONTROL CODE PROVISIONS 3

2.1 OUTDOOR NOISE ISOLATION AND ACOUSTICAL PRIVACY 3

2.2 IMPACT NOISE ISOLATION AND MECHANICAL EQUIPMENT NOISE 4

3. OVERVIEW OF METHODOLOGY 7 3.1 DEFINITION OF BENEFIT 7 3.2 DATA REQUIRED 7 3.2.1 Building Envelope Noise Isolation Performance 8

3.2.2 Population Noise Exposure 8

3.3 CLASSIFICATION OF BENEFITS 9

3.3.1 Envelope Noise Isolation 9

3.3.2 Interior Wall Noise Isolation 9

3.3.3 Internal Noise 10

3.3.4 Impact Noise 10

3.4 BENEFIT TIME-STREAM ANALYSIS 10

4. ESTIMATION OF BENEFITS 13

4.1 SELECTING THE TIME FRAME 13

4.2 POPULATION NOISE EXPOSURE DISTRIBUTIONS 13

4.3 NOISE ISOLATION PERFORMANCE OF EXISTING CONSTRUCTION 13

4.4 WORKSHEET FORMAT 13

4.5 NOISE IMPACT ESTIMATES 14

4.6 DETERMINATION OF NET BENEFITS 14

4.7 EVALUATION OF BENEFITS FOR ALTERNATIVE LEVELS

OF ENVELOPE NOISE ISOLATION 14

5. EXAMPLE OF A BENEFIT ANALYSIS 15

5.1 POPULATION DISTRIBUTIONS 15

5.2 BUILDING ENVELOPE NOISE ISOLATION 17

5.3 ESTIMATION OF NOISE IMPACTS 17

5.3.1 No-Action Alternative 17

5.3.2 Implementation Alternative 19

5.3.3 Summary of Estimates 20

5.4 ESTIMATION OF BENEFITS 21

5.4.1 Benefit Based on Outdoor Noise Impact 22

5.4.2 Benefit Based on Indoor Noise Impact 22

5.5 INTERPRETATION OF BENEFIT ESTIMATES 22

5.6 PRESENTATION OF ESTIMATES 22

5.7 SINGLE-POINT BENEFIT ESTIMATES 23

6. CONCLUSIONS 39

7. REFERENCES 40

v
TABLE OF CONTENTS (Continued)

APPENDIX A - ESTIMATION OF NOISE IMPACT A-l

A. 1 POPULATION DISTRIBUTION WITH SOUND LEVEL A-l

A. 2 WEIGHTING FUNCTIONS A-2

A. 3 LEVEL WEIGHTED POPULATION A-3

A. 4 NOISE IMPACT INDEX A-3

A. 5 OBSERVATIONS A-3

APPENDIX B - ESTIMATION OF OUTDOOR-TO-INDOOR NOISE ISOLATION

OF EXISTING CONSTRUCTION B-l

B. l CLASSIFICATION OF SITE CONDITIONS B-l

B.2 MEAN VALUE AND STANDARD DEVIATION B-2

B.3 DISTRIBUTION OF ENVELOPE NOISE LEVEL REDUCTION B-4

B.4 ESTIMATES OF NATIONAL AVERAGE DISTRIBUTION B-5

APPENDIX C - WORKSHEET FOR NOISE-IMPACT ANALYSIS C-l

vi
I

LIST OF FIGURES

Page

Figure 3.1 General characteristics of a noise impact assessment for

implementing noise control requirements on a product 12

Figure 5.1 Population change and Level Weighted Population for years

in the time-stream 36

Figure 5.2 Population change and Noise Impact Index for years in the

time-stream 37

Figure 5.3 Population affected, change in indoor Noise Impact Index,

and change in indoor Level Weighted Population for years

in the time-stream 38

Figure B.l Envelope noise level reduction distribution for data in

table B.2 B-7

vii
LIST OF TABLES

Page

Table 2.1 Model Noise Control Provisions Developed by Bolt, Beranek,

and Newman, Inc 3

Table 2.2 Model Noise Control Code Specifications (Decibels) for

Outdoor Noise Isolation and Acoustical Privacy 5

Table 2.3 Major Building Components Affected by the Outdoor Noise

Isolation and Acoustical Privacy Provisions of the MNCC .... 5

Table 5.1 Estimated Population Distribution to Highway Traffic Noise

(reference 12) 24

Table 5.2 Estimated Change in Population Distribution to Highway

Traffic Noise (see table 5.1) 25

Table 5.3 Distribution of Population Between Construction Categories

based upon Example Implementation Scenario 26

Table 5.4 Building Envelope Noise Isolation: National Average for

Highway Traffic Noise (see Appendix B) 27

Table 5.5 Completed Worksheet for Noise-Impact Analysis: No-Action

Alternative for 1995 28

Table 5.6 Completed Worksheet for Noise-Impact Analysis: Existing

Construction for 1995 29

Table 5.7 Completed Worksheet for Noise-Impact Analysis:

Construction Conforming to MNCC Provisions for 1995 30

Table 5.8 Summary of Level-Weighted Population Changes for Example

Benefit Analysis 31

Table 5.9 Noise-Impact Estimate for the No-Action Alternative 32

Table 5.10 Noise-Impact Estimate for the Example Implementation

Scenario for the MNCC 33

Table 5.11 Benefit Estimates for the Example Implementation Scenario

for the MNCC 34

Table 5.12 Presentation Format for Final Benefit Estimates

(Data-rounded from table 5.11 estimates) 35

Table B.l Mean Value and Standard Deviation of Envelope Noise-Level

Reduction: Existing Construction (reference 15 and

as noted) B-3

viii
LIST OF TABLES (Continued)

Page

Table B.2 Example Calculation of Distribution of Envelope Noise Level

Reduction B-6

Table B.3 Percentage Distribution of Envelope Noise Level Reduction

for Existing Construction B-8

Table B.4 Percentage Distribution of Envelope Noise Level Reduction:

National Averages for Existing Construction B-9

Table C.l Blank Worksheet for Noise-Impact Estimates C-2

1 . INTRODUCTION

1.1 PURPOSE AND SCOPE

The purpose of this report is to present a uniform method for estimating

benefits of incorporating noise control requirements for new residential and

educational buildings. The primary benefits that may be estimated using this

model are those accruing from noise-isolation requirements for the building

envelope. Benefits related to noise isolation requirements for interior

partitions and f loor/ceiling assemblies and mechanical equipment noise can only be addressed in general terms.

The costs related to achieving the benefits described in this report are not

addressed. These costs may be estimated using the methodology described in

reference [1].

To illustrate the use of the benefit model, a particular noise-control code,

called the Model Noise Control Code (MNCC), is used. This proposed model code was developed under the sponsorship of the U.S. Environmental Protection Agency

(references [2] and [3]). Unique to the MNCC are the variable performance

requirements based upon expected noise levels surrounding the buildings in

question. In contrast, current building noise-control provisions in the Appendix of the Uniform Building Code are fixed performance requirements independent

of the outdoor noise surrounding the building, reference [4]. As described in

the MNCC document, the MNCC provisions could be substituted for the current

building noise-control provisions contained in the Appendix, chapter 35, "Sound

Transmission Control," of the Uniform Building Code. The performance requirements of the MNCC are restricted to residential and educational buildings.

The benefit model described in this report may be used to assess alternative

noise-isolation requirements for any proposed level of isolation. The model

requires input data based upon local conditions at a future point in time.

These data define the distribution of population with outdoor noise levels

and the noise-isolation performance of existing local construction. If

noise-isolation data are not available, a method is described for estimating

the required data based upon local considerations.

1.2 ORGANIZATION

Section 2 of this report begins with an overview of the specific provisions

of the acoustical performance code used to illustrate the model, the MNCC,

and identifies the types of buildings affected by each provision. The

detailed acoustical performance requirements specified by the MNCC provisions

are presented in tabular form and interpreted.

Section 3 is an overview of the benefit model. A benefit, as defined for this

model, is a decrease in noise impact. The decrease is measured relative to

continued use of existing construction and is attributable to the noise-control

provisions being considered. The data requirements to use the model are described and the classification of the benefits are discussed. Since the

1
reader may not be familiar with noise Impact assessments, the necessary

considerations are presented.

Section 4 Is a guideline to the steps necessary to conduct a benefit analysis

using the model. These guidelines are necessarily general since the model's

format allows the user to Incorporate local data at various levels of detail.

Section 5 Is a very detailed example of a benefit analysis using the model and

the MNCC provisions. The example Is an estimate of benefits for the United

States' population resulting from Implementing the MNCC requirements. This

example considers only highway traffic noise. However, the detailed discussions In the example Indicate tabular formats and data summaries that apply

to all local conditions.

There are three appendixes to this report. Appendix A Is a brief discussion

of the methodology used to conduct a noise Impact estimate. Appendix B

presents a method for estimating the noise Isolation performance of existing

construction Incorporating local conditions. This method may be used If

local data are not available. Appendix C Is a blank copy of a worksheet that

Is useful In conducting the benefit analysis.

2
2. MODEL NOISE CONTROL CODE PROVISIONS

This section reviews the provisions of the MNCC used to illustrate the benefit

assessment method and identifies the building types and major building envelope

components affected by those provisions. The purpose here is to provide the

reader with a brief description of the MNCC sections which are specifically

addressed by the methodology. For more elaborate details on these MNCC provisions, the reports prepared for the Environmental Protection Agency should be

consulted [2,3].

2.1 OUTDOOR NOISE ISOLATION AND ACOUSTICAL PRIVACY

Table 2.1 presents the titles of the four MNCC provisions and indicates the

building types affected by each. The first two provisions, Outdoor Noise

Isolation and Acoustical Privacy, both govern the transmission of airborne

noise into and within buildings. It is expected that these provisions would

account for most of the benefits resulting from widespread adoption of the

MNCC. The acoustical provisions contained in building codes today are generally presented in terms of a fixed acoustical performance requirement

[5]. In contrast, the airborne noise requirements of the MNCC vary as a function of the outdoor acoustical environment. This acoustical environment

is measured in decibels of outdoor day-night sound level which is defined as "...the equivalent A-weighted sound level during a 24-hour period with 10

decibels added to the equivalent A-weighted sound level during the nighttime

hours (10:00 p.m. to 7:00 a.m.)" [6].

The Outdoor Noise Isolation provision (section 3507) imposes outdoor noise

isolation requirements on the exterior shell of the building. It affects both

residential and educational buildings exposed to outdoor day-night sound

Table 2.1. Model Noise Control Provisions Developed by

Bolt, Beranek, and Newman, Inc.

Provision Buildings Affected3

Outdoor Noise Isolation (sec. 3507) R

b E

Acoustical Privacy (sec. 3504) R E

Impact Noise Isolation (sec. 3505) R

Mechanical Equipment Noise (sec. 3506) R E

3 Key: R = Multifamily highrise, lowrise, and townhouse buildings.

E = All educational buildings.

b Also applies to single family dwellings.

3
levels 1 greater than 60 dB. As Indicated In table 2.2, the outdoor noise

isolation requirements vary directly with changes in the outdoor sound levels.

The Acoustical Privacy provision (section 3504) imposes performance

requirements for airborne noise transmission reductions for multifamily

residential and educational buildings. These noise transmission reduction

requirements distinguish two types of acoustical privacy by building separations (e.g., f loors/ceilings or interior walls): 1) interior private to

private dwelling unit separations (party walls); and 2) interior public to

private dwelling unit separations.

The Acoustical Privacy requirements vary inversely with changes in the outdoor

sound level within a range from 60 dB and lower. These requirements, however,

become constant above 60 dB.

The predominant construction cost impacts of the performance requirements for

Outdoor Noise Isolation and Acoustical Privacy given in table 2.2 affect five

different building components^. Table 2.3 lists these components and indicates

which provisions affect each component. The exterior walls are affected by the

Outdoor Noise Isolation provision. Windows and doors are affected by both

provisions. Interior walls and floor/celling assemblies are affected only by,

the Acoustical Privacy provision [1]. The benefits accruing from the Outdoor

Noise Isolation provisions may be quantified using the model described in this

report.

2.2 IMPACT NOISE ISOLATION AND MECHANICAL EQUIPMENT NOISE

The other two provisions listed on table 2.1 are Impact Noise Isolation and

Mechanical Equipment Noise. The Impact Noise Isolation provision (section 3505)

calls for prescriptive compliance with a Construction Handbook of approved

designs for impact noise reduction^. This provision could not be addressed by

the methodology presented in this report because the proposed Construction

Handbook of acceptable designs has not yet been prepared. If this provision

were implemented it would primarily affect multifamily residential buildings.

The fourth provision addresses Mechanical Equipment Noise (section 3506). This

provision requires that both multifamily residential and educational buildings

control the noise transmission from various building machinery and appliances.

1 The term "levels'* refers to the 24-hour day-night sound level.

^ The Outdoor Noise Isolation requirement may also affect the construction cost

of roofs. This component is not included in the analysis since its impact on

the entire cost of a highrise building is likely to be minimal. Further, the

increment in benefits may not be significant. For single family dwellings

construction costs related to roofing may be important, however.

OJ For justification of the use of prescriptive, rather than performance,

requirements for Impact Noise Isolation, see reference [2], p. 45.

4
Table 2.2. Model Noise Control Code Specifications (Decibels) for Outdoor Noise

Isolation and Acoustical Privacy

If Outdoor

Day- Night

Sound Level

Outdoor Noise

Isolation

(sec. 3507)

Acoustical Privacy

(sec. 3504)

> < Outside to Insidea Public to

Private*5 Private toPrivate*5

50 — 55 60

50 55 - 50 55

55 60 - 45 50

60 65 20 40 45

65 70 25 40 45

70 75 30 40 45

75 80 35 40 45

80 ***********C0NSTRUCTI0N PROHIBITED***********

a The difference, in decibels, between the outdoor equivalent A-weighted sound

level and the corresponding equivalent A-weighted sound level in the receiving

space. Denoted by AL^ in this report.

k The Normalized Sound Level Difference as defined in reference [2], p. 29.

The MNCC recommends that these values be increased 5 dB when using STC as the

design requirement.

Table 2.3. Major Building Components Affected by the Outdoor Noise Isolation

and Acoustical Privacy Provisions of the MNCC

Building Component

Outdoor Noise Acoustical

Isolation Provision Privacy Provision

Exterior Walls and Roof X

Windows X X

Doors X X

Interior Walls (Partitions) X

Floor/Ceiling Assemblies X

5
The Mechanical Equipment Nolee provision specifies that the A-weighted sound

levels produced by the operation of mechanical equipment be no greater than

45 dB In any dwelling unit or guest room. It also specifies that operation

of appliances produce an A-welghted sound level no more than 70 dB and food

waste disposals no more than 88 dB.

6
3. OVERVIEW OF METHODOLOGY

The method or model described in this report attempts to quantify benefits

attributable to implementation of noise control requirements in building codes.

This section describes an overview of the model and the type of benefits

addressed. The following section presents more detail concerning the application of the model to local conditions. Since the model incorporates many

specific steps that are influenced by local conditions a comprehensive example

is presented in section 5.

3.1 DEFINITION OF BENEFIT

The benefit model described in this report attempts to quantify noneconomic

benefits that may be assigned to a segment of the population within a community.

The population considered in the analysis is the population residing in new

construction at future points in time. The model is based upon the recognition

that noise can cause an adverse environmental impact on this population [7].

As a result, a "benefit" estimated using this model is defined as a mitigation

of adverse environmental noise impact. This definition establishes the framework of the model — the estimation of environmental noise impact on a segment

of the population.

Accepted techniques are available for conducting environmental noise impact

assessments [6]. These techniques are applied in this model. The application,

however, required an extension of these techniques to incorporate the effect

of noise isolation provided by the building construction. The basic steps in

the noise impact analysis are quite simple: 1) determine the population

affected by the proposed action, 2) determine the noise exposure of this

population, and 3) estimate the noise impact. To evaluate the benefits or reduction in the noise impact, it is necessary to establish a bench-mark for

comparisons. The bench-mark is the no-action alternative and for this model

corresponds to no change in the building codes to incorporate noise control

requirements. Appendix A briefly describes the accepted methodology for

conducting noise impact assessments.

3.2 DATA REQUIRED

As stated above, three steps are required to determine the noise impact for

both the no-action alternative and the alternative of implementing noise

control requirements. To obtain a quantitative estimate of either noise

impact or benefits, it is necessary to obtain local data for input into the

model. These data correspond to population projections, future noise

environment, and the noise isolation performance of existing construction.

The aggregation of these local data is the most important and time-consuming

task for any benefit assessment. Much of the data will be available through

local planning activities, however, and it is only necessary to aggregate the

data in the format required by the model. Based upon the available information, the data format is dictated by the noise isolation performance of the

existing construction.

7
3.2.1 Building Envelope Noise Isolation Performance

One very important aspect of noise control requirements for building

construction is the specification of the outdoor-to-indoor noise isolation of

the building envelope. One measure of the envelope noise isolation performance

is the A-weighted sound level difference. This is a single number characterizing the envelope performance and is the requirement used in the Model Noise

Control Code (MNCC) described in section 2 (see table 2.2). This requirement

is based upon the outdoor day-night sound level expected at the building site.

However, the de facto building envelope noise level reduction or noise

isolation performance, as measured by the A-weighted sound level difference,

depends upon the dominant source of outdoor environmental noise. The technical

basis for this distinction is discussed in Appendix B.

One characteristic of this benefit model is that it allows the consideration

of different sources of outdoor noise to be incorporated into the assessment

of benefits. This is achieved by attributing different noise isolation

performance estimates for the building envelope on the basis of the dominant

source of outdoor noise. These performance estimates apply to existing

construction and are described in Appendix B. The three dominant outdoor

noise source categories addressed in Appendix B are: 1) aircraft noise,

2) highway traffic noise, and 3) urban noise.

As a result, the model may incorporate an assessment of benefits accruing to

three population categories: 1) population exposed mainly to aircraft noise,

2) population exposed mainly to highway traffic noise, and 3) population

exposed to "urban noise."

As described in the example benefit analysis in section 5, the model requires

an estimate of the distribution of the building envelope noise level reduction

for existing construction. This distribution may be based upon available local

data. In the absence of local data, the methodology of Appendix B may be used

to obtain an estimate appropriate to the local conditions. The method is,

however, an approximation technique.

3.2.2. Population Noise Exposure

The most important input for a noise impact assessment is the estimation of

population noise exposure. This estimate is a data aggregation that assigns

or distributes the population to the range of environmental noise in the

community. This estimate requires a knowledge of the noise exposure of land areas and the population residing in these land areas. Since this benefit

model addresses new construction at a future point in time, the population

noise exposure estimates are based upon future land development and the future

noise levels. The MNCC requirements specify that the noise control requirements be established on the basis of future noise levels and provide methods

for predicting these levels [2,3].

The format of the population noise exposure data required by the benefit model

is illustrated in tables 5.2 through 5.7 in the example benefit analysis. Such

data may be obtained, for example, from local authorities or federal agencies.

8
The recently enacted Part 150 of the Federal Aviation Administration regulations

require airport operators to determine the aircraft noise impact for land areas surrounding airports [8]. These data will be in a format directly applicable

to this benefit model. Estimates of land exposure to future levels of highway

traffic noise may be obtained from environmental impact statements of major

highway projects.

The benefit model requires an estimate of future population noise exposure at

levels of environmental noise equal to or greater than a day-night sound level

of 55 dB. These data are aggregated into intervals of noise exposure. The

intervals used by the model are 5 dB intervals as recommended for noise impact

estimates (see Appendix A and reference [6]).

Since the model allows the consideration of different outdoor noise sources,

the population noise exposure data should be aggregated on this basis. The

envelope noise reduction levels for aircraft noise are appropriate for land areas around airports. The envelope noise reduction levels for highway

traffic noise are appropriate for land areas adjacent to interstate highways

and major arterials. The envelope noise reduction levels for urban noise

environments is appropriate to land areas on local streets away from other

major noise sources. The extent of detail to incorporate into the local benefit analysis using the present model is entirely a local decision. It is

essential, however, to understand that the population noise exposure data are aggregated on the basis of the expected noise environment and dominant noise

source.

3.3 CLASSIFICATION OF BENEFITS

The benefits accruing from implementation of noise control requirements may be

classified according to the interior noise environment in the living unit. The

interior noise environment is comprised of three components: 1) interior noise

due to outdoor noise, 2) interior noise due to sources in other living units,

and 3) interior noise generated within the living unit. These components are discussed in relation to the MNCC requirements.

3.3.1 Envelope Noise Isolation

The envelope noise isolation performance applies to all residential and

educational construction and determines the interior noise due to outdoor noise

sources. This component of the interior noise environment may be quantified

using existing measures of noise impact and is the component of interior noise

used in this benefit model. For higher levels of outdoor noise, the MNCC

requires increased envelope noise isolation performance (see table 2.2).

3.3.2 Interior Wall Noise Isolation

The interior wall noise isolation performance of the MNCC applies to

multifamily residential and educational construction. The code requirements

specify an increased interior wall noise isolation performance for decreasing

levels of outdoor noise (see table 2.2). This requirement is the most

important aspect of the MNCC specifications and is the most difficult to

9
evaluate quantitatively on the basis of potential benefits. For a benefit

analysis one must quantify the noise sources on a consistent basis. Hence, it

is necessary to assess the levels of interior noise generated by neighbors.

Only a very limited data base exists for estimating these levels [7,9]. Further,

the interior wall noise isolation requirements apply mainly to the population

exposed to outdoor day-night sound levels below 60 dB. This is a very large

segment of the total population. As a result, even a small change in interior

noise attributable to sources in other living units would result in a large

noise impact estimate. Hence, any inaccuracies in estimating the level of

interior noise would result in, perhaps, meaningless benefit estimates. For

these reasons, the present model cannot address benefits — which may be

substantial — attributable to the interior wall noise isolation requirements.

3.3.3 Internal Noise

The MNCC provisions specify levels of interior noise attributable to mechanical

equipment and appliances. The considerations for conducting a benefit analysis

attributable to this requirement are identical to those described in

section 3.3.2 and are not addressed by the present model.

3.3.4 Impact Noise

The MNCC uses a prescriptive, rather than a performance, requirement for impact

noise isolation (see section 2.2). Further, with present-day knowledge, it is

difficult to assess benefits attributable to abatement of impact noise [10].

For these reasons this model does not attempt to assess these benefits. The

significance of impact noise reduction is, however, very great in relation

to occupant's satisfaction with their living environment [10].

3.4 BENEFIT TIME-STREAM ANALYSIS

Noise impacts and benefits will vary from year-to-year. For example, a fixed

population exposed to increasing levels of environmental noise represents an increasing noise impact. Similarly, an increasing population exposed to a constant level of environmental noise represents an increasing noise impact.

The first situation may correspond to a residential development adjacent to a highway that experiences an ever-increasing traffic flow with the attendant

increasing noise levels. The second example corresponds to development of

land for residential use adjacent to a major highway carrying a constant

traffic flow. A noise impact assessment must account for these long-term

time-varying characteristics. Since the benefits depend upon the noise impacts

for the no-action and the implementation alternatives, the estimated benefits

will also vary with time. These considerations are discussed in this section.

The benefit model may be used to estimate these time-varying effects at future

points in time.

Figure 3.1 illustrates the general characteristics of a noise impact estimate

with time. The vertical scale is a "noise impact indicator" which is a numerical value that establishes the noise impact [6,7,11]. The horizontal

scale is time measured in years. Two noise impact curves are indicated in

figure 3.1: the no-action alternative and an alternative representing the

10
implementation of noise control requirements on a product. The no-action

alternative simulates the continued production and use of the product in the

present-day condition. In figure 3.1, the "present day" is a point in time

before the year Yj. In relation to implementing noise control requirements

in buildings, the "product" is, of course, building construction.

The solid line represents the noise impact related to the no-action alternative

and is shown increasing with time. The slope of this line represents the rate

of increase of the noise impact. In relation to the present model, this rate

of increase corresponds to both the population in a community moving into new

construction and increased exposure to environmental noise.

The dashed line represents the noise impact related to implementing noise

control. The difference between these two lines is the "benefit" of noise

control. The numbers B^ and B2 in figure 3.1 are benefit estimates at future

points in time. Since the dashed line is below the solid line, these benefits

are positive numbers indicating a positive benefit of implementing noise

control. The benefit model described in this report is simply a method of

computing points on the lines corresponding to the no-action alternative and

the implementation of noise control requirements for building construction.

In figure 3.1, the year represents the future point in time at which

products featuring noise control enter service. The year Y2 represents the

future point in time at which all products in service feature noise control.

Beyond the year Y2 the noise control requirements are fully effective since

they apply to all products either in service or entering service.

In relation to implementing noise control requirements in building codes, the

time span between initiating the requirements, year Yj in figure 3.1, and

achieving total effectiveness, year Y2 , is the time required to totally replace

all buildings in a community. Obviously, this time span is beyond the life of

the population. Hence, the benefits that may be estimated at a future point

in time within the planning framework of a community will always be less than

the ultimate benefits that can be expected to accrue to future generations.

11
s

M

CN

o

>*

12

Figure

3.1

General

Characteristics

of

a

Noise

Impact

Assessment

for

Implementing

Noise

Control

Requirements

on

a

Product.
4. ESTIMATION OF BENEFITS

This section is a guideline for estimating benefits of implementing noise

control requirements for building codes using local data. A detailed discussion

is not presented in this section but is included in the following section relative to an example benefit analysis. In order to estimate a benefit it is not

necessary to conduct a complete time-stream analysis as indicated in figure 3.1.

It is only necessary to estimate, at a selected future point in time, the proportion of population residing in new construction built under existing code

requirements and population residing in new construction built under the code

provisions corresponding to implementation of noise control requirements.

4.1

SELECTING THE TIME FRAME

As recommended by the implementation manual for the MNCC, a 20 year future

point in time may be used to estimate the noise impact [3]. This 20 year time

is measured from the time at which the noise control requirements are initiated

(year Yj_, in figure 3.1). From this point in time it is necessary to estimate

the population that will eventually occupy the new construction and the distribution of this population with the outdoor day-night sound level. Since the

noise impact assessment must include all population exposed to indoor noise

levels above 42.5 dB, it is necessary to estimate the proportion of the population that resides in buildings exempted from the noise isolation requirement

and the population in buildings requiring a specified level of noise control.

(The 42.5 dB indoor criterion for determining noise impact is discussed in

Appendix A.)

4.2

POPULATION NOISE EXPOSURE DISTRIBUTIONS

As discussed in section 3.2.2 it is necessary to aggregate population data by

the estimated level of noise exposure, and if required, the aggregation may be

further refined by the dominant source of outdoor noise (see section 3.2.1).

4.3

NOISE ISOLATION PERFORMANCE OF EXISTING CONSTRUCTION

The noise isolation performance of existing construction may be estimated using

the methodology in Appendix B or may be based upon available local data. As

described in section 3.2.1, these data are in the form of a distribution and

may be further refined by categories of dominant outdoor noise source.

4.4

WORKSHEET FORMAT

A worksheet has been developed to assist in conducting the noise impact

estimate. A blank sample of this worksheet is presented in Appendix C. A

worksheet must be filled out for each population distribution described in

section 4.1 and 4.2, the appropriate noise isolation distribution described

in section 4.3, and the noise control requirements being implemented. (The

example in section 5 illustrates this process.) The required calculations

are then conducted using the worksheet.

13
4.5 NOISE IMPACT ESTIMATES

The baseline or no-action alternative noise impact estimate is determined from

the worksheets by the combination of population distributions to outdoor noise

and the envelope noise level reduction distributions for existing construction.

Two noise impact estimates are obtained from each worksheet: impact due to

population exposure at outdoor noise levels and impact due to population exposure at indoor noise levels. The final noise impact estimates are obtained by

summing the outdoor noise impacts for all categories of outdoor noise sources

and by summing the indoor noise impacts for all categories of outdoor noise sources

For the noise control alternative, an identical set of calculations is performed

with the only extension being that impacts must be estimated separately for the

population residing in new construction exempted from noise control (outdoor

levels below 60 dB) and the population residing in new construction requiring

noise control (outdoor levels above 60 dB). The 60 dB limit referred to is the

limit specified by the MNCC and is used here to denote the separation of population categories. The model allows the user to select other limits if so desired.

4.6 DETERMINATION OF NET BENEFITS

The result of the calculations described in Section 4.5 is two sets of numbers

that estimate the noise impact in a future year. One set of numbers represents

the noise impact based upon population exposure at outdoor levels for the no- action and the noise control alternative. The difference between these two

numbers (no-action value less noise control value) represents the benefit to

the population based upon exposure at outdoor noise levels. This estimate

is required since the MNCC provisions prohibit construction in land areas exposed to outdoor day-night levels exceeding 80 dB.

The other set of numbers represents the noise impact based upon population

exposure at indoor noise levels for the no-action and the noise control

alternative. The difference between these two numbers represents the benefit

to the population based upon exposure at indoor noise levels. This benefit is

expected to be the major benefit resulting from implementation of the outdoor

noise isolation requirements of the MNCC.

4.7

EVALUATION OF BENEFITS FOR ALTERNATIVE LEVELS OF ENVELOPE NOISE ISOLATION

The benefit model may be used to estimate alternative levels of building

envelope noise isolation than the levels prescribed by the Model Noise

Control Code described in Section 2. The brief guidelines in this section

are the general steps required to conduct a benefit analysis. The following

section presents a detailed example illustrating the many considerations and

steps described above using the MNCC provisions as the example of noise

control requirements.

14
5. EXAMPLE OF A BENEFIT ANALYSIS

This section presents an example of a benefit analysis of implementing noise

isolation requirements for building envelopes. The outdoor noise isolation

provisions (sec. 3507) of the MNCC are used as the example requirements. An

estimate of the national population exposure to highway traffic noise is used

as the basis for determining expected benefits. A time-stream benefit analysis

is used to illustrate the time effects of implementing the noise isolation

provisions.

Each step in this example is discussed so that the basic considerations may be

clearly understood. These steps are identical to those required to conduct a similar analysis at a local level using data appropriate to the community.

5.1 POPULATION DISTRIBUTIONS

The first step in the benefit analysis is the estimation of population

distribution with respect to the outdoor day-night sound level, L<jno. Table 5.1 presents an estimate for the distribution of the national population

noise exposure due to highway traffic noise [ 12 ] ^This estimate assumes that

highway traffic noise remains unregulated and that the national population

increases at a rate based upon historical trends. It is beyond the scope of

this example to further describe the basis for the table 5.1 estimate.

However, the format of the data will be described since local data aggregations

should follow a similar format.

Each entry in table 5.1 is a population estimate with the columns representing

years. In this example, five year increments are used beginning with the

reference year 1980 through the year 2010. The first six rows of table 5.1

indicate intervals of outdoor day-night sound level, L^nO* These intervals

cover the range of 55 dB through 85 dB in 5 dB intervals corresponding to the

MNCC specifications in table 2.2. The last four rows are summary entries

indicating the population distribution to ranges of outdoor day-night sound

levels. The last row is the total population estimate.

Since benefits resulting from implementing any building code requirement

applying to new construction can only be attributed to the population residing

in the new construction, it is necessary to estimate this segment of the

population. To do this, the change in population distribution is required.

The estimated change in population distribution in future years relative to

the reference year (1980) is easily obtained from the table 5.1 data. The

result is presented in table 5.2.

The next step is to estimate the proportion of the population that will reside

in new construction and the time sequence for implementation of the noise control requirements. Estimates of population increases residing in new

construction may be obtained based upon construction trends and averages of

1 All tables and figures in this section are included at the end of the section

for easy reference with the text.

15
occupancy per type of living unit. For the purposes of this example, it will

be assumed that the total population change resides in new housing. However,

based upon local conditions, it may be desirable to adjust the data for distribution between existing construction and new construction. The time

sequence for implementing noise control requirements presents a similar consideration and will be emphasized in the present example.

The following implementation scenario is used to illustrate the considerations.

First, it is assumed that all new construction through the year 1985 complies

with "current building code" requirements. That is, the outdoor-indoor noise

isolation corresponds to existing construction performance. Beginning in 1985

through 1990 a transition occurs such that at the end of 1990 half of the

population increase for this time period resides in new construction conforming

to the MNCC requirements and the other half resides in new constructtion

conforming with the "current building code." Finally, it is assumed that all

new construction beyond 1990 conforms with the MNCC requirements. (It is

emphasized that this implementation scenario is an example and it is recognized

that a national implementation based upon consensus standards is difficult — if

not impossible — to formulate. The example, however, does illustrate the steps

required to evaluate benefits based upon local considerations.)

Table 5.3 illustrates the effect of the above scenario on the population

distribution with outdoor day-night sound level. Several details in table 5.3

must be mentioned since they reflect the MNCC requirements. First, two segments

of the population are identified for each year in the analysis: population

residing in new construction complying with current building codes (CBC) and

construction complying with the Model Noise Control Code (MNCC). This distinction is necessary since the benefits must be compared to the "baseline"

alternative of not adopting the MNCC requirements.

The first note concerning the data entries in table 5.3 is that the segment of

the population exposed to outdoor noise in the 55-60 dB interval is allocated

to the "current building code" column. The reason for this is that the MNCC

allows "existing construction" for these conditions. Next, it should be noted

that beginning in 1995 and beyond, no population is allocated to the 80 to

85 dB range other than the population allowed under "current building code"

requirements prior to 1990. For the population increases in the 80 to 85 dB

range indicated in table 5.2, the changes in population have been allocated to

the 75-80 dB range for MNCC requirements in 1995 and beyond. This allocation

reflects the "construction prohibited" requirement of the MNCC. Other than

the 75-85 dB interval, the total population at all sound levels and ranges

for each year is identical for the table 5.2 data and the table 5.3 data.

The table 5.2 data are used to obtain the noise impact estimate associated

with the no-action alternative of utilizing existing construction. The

table 5.3 data are used to obtain the noise impact estimate associated with

the example implementation scenario for the MNCC as described above. To do

this it is necessary to estimate the outdoor-to-indoor noise isolation for

existing construction.

16
5.2 BUILDING ENVELOPE NOISE ISOLATION

The building envelope noise isolation must be estimated for existing

construction. The noise isolation characteristics are described by a distribution. This distribution represents the fraction of existing

construction exhibiting noise isolation characteristics of a given value. The

methodology described in Appendix B may be used to obtain estimates based upon

local conditions. For this example problem, it is appropriate to use the

"national average" noise isolation distribution for highway traffic noise.

This distribution is presented in table 5.4 and is derived in Appendix B. It

incorporates assumptions concerning open and closed windows and the distribution of population between cold and warm climate conditions. Details are discussed in the Appendix.

Comparing this distribution with the MNCC requirements in table 2.2, it is seen that over 50 percent of existing construction would comply with the

minimum MNCC requirement of 20 dB and less than one percent of existing

construction is estimated to exceed the maximum MNCC requirement of 35 dB.

The significance of this observation is that existing construction will

partly mitigate outdoor noise intrusion when compared to the population

distribution with outdoor day-night sound level as required by the MNCC.

The basic assumption of this model is that the distribution of noise

isolation of existing construction is independent of the outdoor day-night

sound level . This assumption is necessary since data are not available to

estimate a relationship between outdoor day-night sound level and noise

isolation characteristics of existing construction. Since benefits will be

estimated on an incremental or relative basis, this assumption may not be

expected to be too critical to the final result.

5.3 ESTIMATION OF NOISE IMPACTS

The noise impact estimate must be conducted for two alternatives: 1) the

no-action alternative, and 2) the adoption of noise control requirements.

The data in table 5.2 are used to estimate the noise impact of the no-action

alternative. The data in table 5.3 are used to estimate the noise impacts

associated with the adoption of the MNCC requirements as described in

section 5.1. Further, since the MNCC requirements prohibit construction in

land areas exposed to noise levels greater than 80 dB, it is necessary to

estimate noise impacts for both outdoor and indoor conditions. These estimates are calculated for each of the years indicated in tables 5.2 and 5.3

for each segment of the population under consideration. To assist in

conducting these calculations, a worksheet has been developed. A blank copy

of the worksheet is included in Appendix C. The example data will be used

to illustrate the use of the worksheet for conducting noise impact estimates.

5.3.1 No-Action Alternative

The noise impact estimate for the no-action alternative is conducted for each

year 1985 through 2010 using the data in table 5.2. Data for the year 1995

will be used to illustrate the data entries for the calculation worksheet.

17
Table 5.5 Is the completed worksheet for the no-action alternative In the year

1995. The columns under the heading "OUTDOOR" apply to the outdoor environment

and to the population exposed to the levels of outdoor noise. The columns

under the heading "INDOOR" apply to the estimate of population distribution

with levels of indoor noise from outdoor sources. The population exposed to

Indoor noise levels is Identical to the population exposed to outdoor noise

levels. The worksheet is used to calculate two numbers: the Level Weighted

Populations based on outdoor and indoor noise environments for the same population. (The Level Weighted Population or LWP is one type of noise impact indicator. See Appendix A and References 7 & 11.)

The data entries in the column heading APexp are directly transcribed from

table 5.2 for the year 1995 . The entries under the column heading ALWPq are obtained by multiplying the AP exp entries by the weighting factors WqCL^q)

for each interval of outdoor day-night sound level. The weighting factors are described in Appendix A and are evaluated at the mid-point of the outdoor sound

level interval. The total Level Weighted Population for the outdoor environment is obtained by summing all entries in the ALWPq column. For the example

in table 5.5, this total is 3.5125 million (M) people.

To characterize the indoor environment, it is necessary to estimate the

distribution of population exposed to levels of indoor noise at each level of

outdoor noise. The columns under the heading "INDOOR" correspond to levels of

the building envelope noise level reduction, AL^. At the top of each column,

one enters the appropriate fraction of the building envelope noise isolation.

Since the example in table 5.5 corresponds to existing construction, the data

entries are obtained from the distribution given in table 5.4.

Each cell in the array of table 5.5 corresponds to an Indoor noise level due

to the outdoor noise environment. The indoor level is predetermined by the

worksheet format and is denoted by the entry L^i* For example, with an outdoor environment in the interval 60-65 dB (center at 62.5 dB) and an envelope noise level reduction in the interval 15-20 dB (center 17.5 dB) the

average indoor noise level is estimated to be 45 dB (62.5-17.5). For this

cell, the population experiencing this indoor noise level of 45 dB is estimated

by multiplying the total population in the outdoor interval (3.21 M) by the

fraction of construction exhibiting the level of noise isolation (0.3360) to

obtain the estimate 1.0786 M.

This process is repeated for each cell in the array. Since indoor noise

exposures less than 45 dB are not considered to Impact the population, it is

not necessary to completely fill the table. It is only required to calculate

the indoor population exposure for levels of indoor noise equal to or greater

than 45 dB. The total estimate of population indoor noise exposure is then

obtained at each level of indoor noise by summing each entry in the array at

each level of indoor noise exposure. In the format of table 5.5, the cells

of constant Indoor sound level are located on a diagonal running from upper

left to lower right.

1 A "A prefix is used to denote a quantity based upon a population change.

18
For each level of indoor day-night sound level, L^ni, the accumulated

population exposure is tabulated in the indicated column at the bottom of the

worksheet. At each indoor sound level, the exposed population is multiplied

by the indicated weighting factor for indoor noise intrusion, Wi(L<jn i). (This

weighting factor is also described in Appendix A.) The resulting term is the

Level Weighted Population for indoor noise exposure at the level of indoor

noise. Each of these terms is summed to obtain the final estimate of the

Level Weighted Population for the indoor noise environment, ALWPj. For the

example data in table 5.5, the indoor Level Weighted Population for indoor

noise due to outdoor sources is 1.1829 M people.

In summary, the table 5.5 data provides two numbers: 1) the Level Weighted

Population based upon the outdoor noise environment, ALWPq = 3.5125 M, and

2) the Level Weighted Population based upon the indoor noise environment due to

outdoor noise, ALWPj = 1.1829 M. These estimates are for the year 1995. Similar calculations are conducted for the other years in the time-stream for the

no-action alternative.

5.3.2 Implementation Alternative

The noise impact estimate for the implementation alternative is essentially

identical to that described for the no-action alternative. However, the

calculations involve two population exposure categories for each year of the

time-stream: 1) population residing in existing construction, and 2) population

residing in new construction complying with the MNCC requirements. The population distributions of table 5.3 are used for these estimates.

For the year 1995 and the population distribution given in table 5.3 for the

current building code requirements (existing construction), the worksheet is

used to obtain the estimates: ALWPq = 1.5575 M and ALWPj = 0.4362 M. These

data entries and calculations are illustrated in table 5.6.

For the year 1995 and the population distribution given in table 5.3 for the

MNCC requirements, the worksheet is used to obtain the estimates:

ALWPq = 1.9525 M and ALWPj = 0.2363 M. These data entries and calculations are illustrated in table 5.7.

Comparing tables 5.5 through 5.7, it is seen that the outdoor data manipulations

are identical. However, the indoor data entries for table 5.7 are different

from the entries in tables 5.5 and 5.6. The difference is a recognition — in an accounting sense — of the MNCC requirements. For existing construction

(tables 5.5 and 5.6) the indoor noise environment is a distribution of population exposure at each level of outdoor noise. For the MNCC requirements, the

distribution is condensed into an explicit performance range depending upon the

outdoor noise environment. For example, the MNCC requirements specify an envelope noise isolation of 25 dB for outdoor noise in the interval 65 to 70 dB

day-night sound level. This requirement is reflected in the worksheet format

of table 5.7 by a uniform allocation of the population exposed to 65 to 70 dB

outdoor levels to the two cells corresponding to indoor levels of 40 and 45 dB.

Indeed, at each outdoor level interval, the MNCC requirements specify an indoor

level in the range of 40 to 45 dB (see table 2.2). With this allocation of

19
population, the indoor Level Weighted Population estimates follow in a format

identical to that described in section 5.3.1. The significance of the

table 5.7 calculations is that the MNCC requirements remove all indoor noise

level impact estimates from consideration except for the population exposed to

indoor levels centered at 45 dB.

It may be argued that the uniform allocation for the MNCC is simply an accounting scheme and that other allocations may be more representative of

reality. This argument is accepted. However, the model allows the user to

incorporate his best judgment. For example, if one assumed that buildings

designed to meet the MNCC would incorporate a margin so that the requirement

was always exceeded, the entire exposed population would be allocated to the

40 dB interior noise level of table 5.7. In this case, one would estimate

the minimum noise impact for indoor noise exposure and obtain a maximum benefit

estimate. By shifting the indoor population noise exposure to higher levels

to simulate less stringent noise isolation requirements than the MNCC, one may

still use the model. The point being made is that the model accepts such variations — made at the users' judgment — and that variations are incorporated

at this stage of the noise impact analysis.

5.3.3 Summary of Estimates

The next step in the analysis is to summarize the noise impact estimates for

each year in the time-stream. Based upon the data in tables 5.2 and 5.3, the

noise impact estimates are summarized as indicated in table 5.8. This summary

indicates the relative significance of the population noise exposure calculations for the two alternatives. The no-action alternative data of table 5.8

represent the baseline conditions for comparing the benefits of implementing

the noise control options.

The data in table 5.8 for the MNCC implementation scenario are grouped into

three sets: 1) noise impact related to existing construction; 2) noise impact

related to new construction; and 3) the total noise impact combining these two

impact estimates. The noise impact estimates all increase with time as indicated in table 5.8. However, the increase for each grouping of the population

result from different causes. The increases in the ALWP values for the

no-action alternative result directly from the population increases at all

levels of outdoor noise exposure. For the population residing in existing

construction under the MNCC implementation, the increases in ALWP values result

from population increases for people residing in the 55-60 dB outdoor noise

exposure interval. For the population residing in new construction, the

increases in ALWP result directly from population increases.

Comparing the ALWPq values in table 5.8 for the no-action and the total MNCC

alternatives, it is seen that there is a slight decrease in noise impact

based on the outdoor noise exposure. This is a result of the prohibition of

construction in areas exposed to outdoor levels greater than 80 dB as required

by the MNCC. The small decrease is attributable to the small fraction of the

total population estimated to reside in land areas exposed to levels of

highway traffic noise above 80 dB (see table 5.1).

20
Comparing the ALWPj values in table 5.8 for the no-action and the total MNCC

alternatives, it is seen that there is a rather large decrease in noise impact

based upon the indoor noise exposure. This decrease is, of course, a result

of implementing the MNCC requirements for the outdoor-to-indoor noise isolation.

The ALWP values are one format that may be used to estimate the benefits. An

LWP value represents an absolute estimate in the sense that it attempts to

establish a single number representing an equivalent population. Another

format for estimating benefits, is the single number called the Noise Impact

Index or Nil. The Nil value is the ratio of the LWP value to the total population base for the LWP estimate. The Nil may be presented as a fraction or a percentage as described in Appendix A.

Table 5.9 presents the summary of the population exposed, the ALWP values, and

the ANII values for the no-action alternative of the example. The table

presents both outdoor and indoor noise impact estimates. The population

exposed values are obtained from table 5.2. The ALWP values are obtained from

table 5.8. The ANII values are calculated as the percentage of the ALWP values

relative to the population exposed. It should be noted that the population

exposed value represents the total population exposed to outdoor day-night

sound levels above 55 dB. This segment of the population encompasses everyone

affected by both the outdoor and the indoor noise impact estimates.

At first, the ANII estimates in table 5.9 may appear surprising. The are essentially constant for all years of the time-stream! The value of the ANIIq*

is constant at about 32.5 percent of the population exposed to outdoor sound

levels above 55 dB. The value of the ANIIj, is constant at about 10.9 percent.

One should not, however, be too surprised that these results are constants.

This may be anticipated since the total population growth rate in table 5.1 is

essentially constant. As a result, the ALWP values remain in almost constant

proportion to the population exposed values at each year of the time-stream and

the ANII is simply the proportionality constant.

Table 5.10 presents the ANII estimates for the MNCC implementation scenario.

The values of ANII for the outdoor noise impact estimate are essentially

constant at 32.5 percent. The values of the ANII for the indoor noise impact

estimate, however, are decreasing with years in the time-stream. This decrease

in the indoor noise impact, as measured by the Noise Impact Index, represents

another measure of the effect of implementing the MNCC requirements.

5.4 ESTIMATION OF BENEFITS

The ALWP and ANII estimates summarized in tables 5.9 and 5.10 are used to

estimate the benefits attributable to implementation of the noise control

requirements. As stated in section 3, the term "benefit" is defined as the

decrease in the noise impact as a result of implementing the noise control

requirements. The decrease is measured relative to the noise impact of the

no-action alternative at each year of the time-stream.

21
5.4.1 Benefit Based on Outdoor Noise Impact

The MNCC requirements prohibit construction In land areas exposed to outdoor

day-night sound levels greater than 80 dB. The benefits attributable to this

requirement are estimated by subtracting the values for ALWPq in table 5.10

from the values for ALWPq in table 5.9 for each year in the time-stream.

Similarly, one obtains the benefit in terms of the Noise Impact Index. The

results are presented in table 5.11. For this example, the benefits as measured by the change in ALWPq or ANIIq are too insignificant to warrant any

further consideration. The conclusion, then, is that the MNCC requirements do

not appear to result in any net benefit based upon outdoor noise exposure.

This conclusion, however, applies only to this example. A benefit analysis

based upon local conditions may result in a benefit due to the outdoor noise

restrictions of the MNCC or similar code requirements.

5.4.2 Benefit Based on Indoor Noise Impact

The benefits resulting from implementing the MNCC requirements based on the

indoor noise impacts are estimated as described above for the outdoor benefits.

For the example scenario, the estimated benefits are listed in table 5.11

under the columns headed "INDOOR." In this case, the benefits are significant

for the years 1995 and beyond. The benefit estimate based upon the Level

Weighted Population continually increases as does the estimate based upon the

Noise Impact Index. For this example, the net benefit of implementing the

MNCC requirements are estimated to be a change in Level Weighted Population of

2.84 M or a change in Noise Impact Index of 6.4 percent for the year 2010.

5.5 INTERPRETATION OF BENEFIT ESTIMATES

The question arises as to the significance of the benefit estimates and the

decision to implement the noise control requirements. There is, however, no explicit criterion to apply that will indicate a benefit value above which

implementation is clearly warranted. What the benefit estimates do indicate

is that a positive benefit does result from the proposed action. These benefits accrue to an ever-increasing segment of the national population. In

table 5.11, the column headed "Population Affected" represents the estimated

population residing in buildings incorporating the noise control requirements.

These data are obtained from table 5.3. Hence, implementation of the noise

control requirements, based upon the example scenario, would affect an estimated 21.07 M people by the year 2010 or about 7.1 percent of the national

population.

5.6 PRESENTATION OF ESTIMATES

It is appropriate to discuss formats for presenting results of a benefit

analysis. Tabulated data are necessary to documenc the inputs and the

outputs of the estimates. It will be noted that tables 5.1 through 5.3 present

data with two significant figures to the right of the decimal point. In

tables 5.5 through 5.11, estimates are conducted to four places to the right

of the decimal point. Carrying four-place decimal numbers does not imply

22
accuracy, however. The number of decimal places indicated in tables 5.5

through 5.11 is necessary to avoid errors introduced by rounding. However, it

is appropriate to present rounded numbers in the final presentation of data

such as the benefit estimates of table 5.11. Indeed, the benefit summary in

the format of table 5.11 may be the only information required for a policy

decision. Based upon the example estimates in table 5.11 and the above discussion, table 5.12 is a final presentation of the benefit estimates. The entries

in table 5.12 are rounded from the entries in table 5.11 and convey the same message without implication of unwarranted accuracy.

In addition to tabular data, graphical presentation of both the noise impact

estimates and the benefit estimates are effective formats. Figure 5.1 illustrates the noise impact estimates based upon the Level Weighted Population.

These results are plotted from the data in tables 5.9 and 5.10. Figure 5.2

illustrates the noise impact based upon the Noise Impact Index. These results

are also plotted from the data in tables 5.2, 5.9 and 5.10. Figure 5.3 presents

the benefit estimates of table 5.11 for the indoor conditions. In figures 5.2

and 5.3 it is necessary to approximate the curves based on the ANII index

between the three years 1985, 1990, and 1995. This is the transition period

for the benefit analysis, and as indicated in these figures and table 5.10,

the ANII values are significantly affected.

5.7 SINGLE-POINT BENEFIT ESTIMATES

It is instructive to view the benefit estimates on the basis of a single-point

benefit estimate as discussed in section 4.1. The term single-point estimate

is used to denote a benefit calculation at only one point in the future time

frame. In section 4.1, a 20-year single-point benefit estimate was suggested.

For the example presented here, the 20-year time interval is measured from 1985

(the year in figure 3.1) so that the single-point estimate would be conducted

for the year 2005. The question then arises as to the interpretation of the

benefits knowing only a single estimate.

From table 5.12, the benefit estimates are "no change" for the outdoor sound

exposure, and for the indoor exposure, a change in Level Weighted Population

of 2.01 M and a change of Noise Impact Index of 6.2 percent. As mentioned in

section 3.4 and indicated in figure 3.1, the 20-year time span is expected to

be well within the range for which benefits will continually increase. This

statement, however, applies to absolute measures of benefit such as the Level

Weighted Population. For the Noise Impact Index benefit measure, we note that

this value seems to be approaching a constant with increasing time. This constant, in the example problem, is something slightly above the value of

6 percent of the population exposed to outdoor levels greater that 55 dB.

Hence, as an approximation, if one conducts a single-point estimate, one should

state the estimate in terms of the absolute measure of the Level Weighted

Population emphasizing that this absolute measure is continually increasing

proportional to the rate of change of the benefit estimate based on the Noise

Impact Index. One may be more confident, of course, if a complete time-stream

analysis is performed.

23
Table

5.1.

Estimated

Population

Distribution

to

Highway

Traffic

Noise o O o o o CM 00 OS uo rH fH sT iH os co vO H • • • • O • • • • • • 2

rH sO

CM 2

os ON SO

H o co NO Os

co

H

H rH CM

m

O OS to CM 00 co OS rH o sr o o. <r H • • • . o . • • • » • 5

ON o

CM 00 u-l CO to rH o H SO CO in CO • H H rH CM O OS so rH sO CO m rH 00

rHO Os o O CO H CO rH • • • • o • • • • • • to rH

CM CM CM NO to

H

O NO o to

to CO rH

H

H CM

to os CM r> 00 o sr o SO

H

00 sO

OS r>.

O r> sO CM rH • • » • OS • • • • • • CM Os Os

rH r>. Os ST sr rH o sO OS sr to

to CM iH

H CM o rH Os OS so CM CO CM rH Os

sr CO

O OS so o 1". CO rH rH • • • » os • • • • • • sO rH SO r-» H sf I'M CO sr H O uo ON sr sr

sr CM

H

H CM

CM

m CO LO iH 00 o CO o

00 IT) uo CM

H rH CO C0m so OS . • • • • • • • . • iH CO NO sr rH O tn OS m •4- CM H sr 00 sr CO H CM o O rH Mf NO CM o

00 tn 00 rH rH o rH CM 00 CO o

OS • • • • • • • » • • iH CM m CO rH O uo sO sr CM sr CM rH CO 00 sr CM

dnO rva

O

so

m

so or*%

m o

00

m

oo 4 3 a) 1 1 l 1 1 I m m o H u uo o m o m o m m, sO, O aH m to so r>. r* oo V A| A H

24 ;

ii
O ON vD Mf

m no o o O

O o on CM rH >n O r-'. r>» 00 -dr-t • • • • • • • • • • O r-

CO NO CM o o on sr CM mt

CM CS| rH CM Sj- CM

>,G

!» -C

bOO

4-1 CO

•H

4-> o oo rH NO o m o O o O m ON NO ON m MT o NO m NO rH o • • • • • • • • • • o to ON rH O o ON CM vO CM

CM rH CM co rH NO

ON

m r> o NO co o O rH o o CM CM rH o CM o ON O r- ON o • • • • • • • • • • o o NO CO rH O o 00 rH o ON

CM rH CM CM rH sj- 3

rQ

•HH

4-) XGO

•H rH

4-> • G m

iH3 G

Gj iH O -O

pLl

G

4J

G

•H

GG

G

X

bO

—

GG G GS «W

•H 4-4

4->

G

x

u

W

H

ON rH co CM CO CM o O rH o m CM CM NO m rH O 00 00 NO ON • • • • • • • • • • On m CO rH o o o NO o in

rH CM rH CO

rH 00m o m rH o O ON o o rH CM NO CM o O o co •H CO ON • • • * • • • • • • ON CM rH o o o o rH mt CM m 1—

CM CM

O *H CO MT f". CM CO rH o o r- o O m CM r*» fO rH o O rH m CM NO

•o 5a oo • • • • • • • • • • G ON rH o o o o o O CM rH CM

4-1

O rH rH rH

CMmG

rH

X>GH

•SC oco om

rH00Ml* rH

NO

rH

r*. o

CM

rH CM 00 CO o

ON • • • • • • • • • • i—

CM

m CO Mt rH

O

m NO Mf CM Mt CM rH co

rH 00 Mf CMCM

G S t ONO

mNO o

r^

m

r>. o

00

m

00 3

•G

G 1 i l 1 1 l m

m o EH 3 4J m o m o m o m m, NO, O GM m NO NO r>. 00 V A| A | EH

25 *

Reference

Year

(Totals)
Table

5.3

Distribution

of

Population

Between

Construction

Categories

Based

Upon

Example

Implementation

Scenario

26

Key:

CBC

m

Current

Building

Code

MNCC

“

Model

Noise

Control

Code
Table 5.4. Building Envelope Noise Isolation: National Average

for Highway Traffic Noise (see Appendix B)

Noise Isolation

AL.

Percent of

Existing

Construction

Percent of Existing

Construction

Exceeding Lower Limit

10-15 14.01 100.00

15-20 33.60 85.99

20-25 35.54 52.39

25-30 14.46 16.85

30-35 2.26 2.39

35-40 0.13 0.13

40-45 0.0 0.0

27
Table

5.5.

Completed

Work

Sheet

for

Noise-Impact

Analysis:

No-Action

Alternative

for

1995

Row Total

rJ

tv

CM M*

<rM

03

INDOOR

Distribution

of

Envelope

Noise

Level

Reduction,

AL^.dB

CQ*dmA 0

o'

PQ•d

CQ•doCM

CQ•dmCM

CQ•dom

CQ•dmcn

to•do I

CQ•do omn

rH

(0

ol0o

<r

to8d

CQT>OAm

c08O 8oCM

CQ

•dinCM 38 8mcn s *« 0 « S 5 o

o’

CO•om

so om

CMH

rH

M

CMO• o 0Sq

•d

cq"Om

r-i *

>9

r»«Moo 8mCM

10•dor> 8mcn 8 ? 5 S

BS 8 H 3 8•

•o* £O o o

in

C•

CQT3o

sO omn.

03• O

r~

«o

rJ• «3

fJ

00od

ca•dsaCM

.9*O

so-ooci

CQ•dmm 3 E o 13o

<0 ^

•Oin

•» 04

50

dB 55

dB CQ•dmm oin

PMsO• o

rJdM

«M

tOc

CO•oin

CM1 oCM

H

lA

in«?o

CO•dm

cn

n <0

•o o 5 'l• « id

•o 0"

in I" c t/t d

00 8 M o «

v> “©

55

dB o

.o4d»?_

PQ

—

•o r- o 0 VO Qd

CQ•doin om

r** rnO 6• s

H-c

pa*do

CMm

rH 0

>0£p?o « ^ o r

<*

to 'S ° 03

«n r-

•* 9

•an ^r- 8 5©

PQ l*“ ° M s r:d

no J~|fl o M vO O

C*

*d

O

m

Q vO \JC

CO•dm omCMrHO

r-rM

rv

>9ao

CO*dm

rH1 orH 0Ho

CO -- ° H U1 «— » O

r* « c\ « * S Md " 00 m r* m r*• o «

jr

•O CM o r*

VO

Oo

to fJ

•a oO

vn "

vO

O• O

PQ (P

•d fM S 8d

CQ•do

<r

O

<r- in

V?

C0 o »£

fr

41w

*£ fr 8 5 < j3 aJ

d & , JM Pu< M3 <

PmJ

w g- 1 1

J*

a

Indoor

Day-Night

Sound

Level,

dB

Indoor

Weighting

Factor,

Wy(L, )

Indoor

Population

Exposed, M

(_45<J B)

Indoor

Level

Weighted

Population,

ALWPj M

OUTDOOR s<oIs

O i©

00COo2«0

00o o?

«d

M-5

IPPO

O*

l/» CM

CO oc S3 w

3? o Om

CM*Hd 8r*

cno OmCM• o ( Om

r** 00o omCMH• rH

Om

r>. cn• rH so1<

rH«

4-> H

clH

0) 5 5

<0• CM

c*IP £

CO §

*mo £o

CMOd

rHa ° ? •§s

CQ•ommV

CO•do

so1 mm

CO•din

vD1 ovO

CQ'dOr*m*©

CQ•dmr*1 O

CQ*dO001 inn*CQ

•dm

00I o

00

28
bOe

idW

>1

rH

CO <

4J

CJ

CO0M•Q)

CO •HO

S3MO

<4-1

m 4J OV

<U CTV Q) i-H XCfl M O (3 S3 O

•H T> 4-1 0) o

4-> 3

<D

M

rH 4J (X CO s e o o o u

vOm

d) i—i

HO

cO H * 3

4J

«<* N

rJ

<§ S

<0 $ •• O o

M- IT

COnr

1AA* 0 0©• © o

PA

rH 0o o 0

nrla'O

LA

CM

rH• rH

A8 0

<7

d

© 2o O

*A

00

vf5

IPCO

vO o o ©

o' » olA CPo CMvO M <0

la

la o • O © o’

panr

0.3750 (0

in 0 oLA Pi M • © ©

CQ o (0 r*

AT LA

CM in o

la rH «o *9 d M • o

COnr <0rO o O o

<r c*J N

oo

~vin 2

M*

M ^At»» £J

MC 2

<3 j 3 Mc & co

nr 0) •H

A P* •u H0)> w < td a m

0> T3 o.

hJ •k 0? o U 00 CU

TJ o o c •u cx T3 3 o X <D O 05 w 4-» C/3 fcu X c cm

CO o •H

-c c *H 0) cm iH , s •H •u CO 2 •c pH 1 cm a <D >v •H O. >

01 (1) o 0) o a fU 4 U 1-4 u V4 o o o o o o o o

nr TJ no TJ a e c c M M M M

INDOOR

Distribution

of

Envelope

Noise

Level

Reduction!

AL^.dB

CO•olAA

•O' 0• O 15

dB

20

dB 25

dB.

30

dB 35

dB (0•°o 1

COTJO

<ri LA

PA £00d

COnroCM

CO•o

LACM

to-o8 €

LA

CA „ 0 2 o o o - © 9 i LA 1

CO•o1A

<aoPA

r»r»od

00nr

LACM

€8 9

LA

CA 39 &O 5 ©©

d' « s 5 ©©

rJ

•n! 1. ©

COnr8ACM

d

00nroCA

CO•aLA

CA

r- S cO 5 o• © 2 C° * N 5 0• © « « 'g o o ui d 2 o m 0 m . ©

COnr

LA

CMoCM

HlAm

lOo

CO•d

LA

PA

•o O' o IP - o 5 £ 5 $• ©

50

dB

d.osan « S m — m q©

J ! 9

VO

O• ©

COnr0CM1 LA

rH

O

K»

to• o S r- o rL •» « ^ o ff' « 5? «» fOd « ^ o r « . o

55

dB « ^ a (O o —

vO

©© 2 po

VO- Os•

COnrLA

rH1 orH o

M;d

rt

—

•a

—5 « VP

nroLA ^—• o « £ •° r- S o.© 2 N s ©© « <8

•° V3 m n ° %© « — I o S od 1

4Jw c g

*>• 0 3 f

•V s s & a «

A.<3 i s? M &

J§ o.S < Ma J°M

A<I

OUTDOOR s<o

Is o

p>3• o

«0

oo©

<P

CP

to© 8M

©'

O

inm-©©

<P

*s©d

in

i-tnin

<TNoc

•o JV--* a° o OLA

CM

rHo oLACA• O

OLA

CM

VOo oLA

r*

00o OLA

CMrH

rH

OLACA

rH soI

rH

cd 4JoH

as o

aoJN

CJin

©• in© • ©

©©

©• ©

rH

cd o > 2$ J %iH

COnr

LALAV

COT>OVO1 LALA

00•a

LA

vOi oVO

CO•oor*I LAvO

COnr«A

r^.1 o

COnro

00i LA

r^-

00n)LA

00o00

29
Table

5.7.

Completed

Work

Sheet

for

Noise-Impact

Analysis:

Construction

Conforming

to

MNCC

Provisions

for

1995

g

03 4J 8 s5

3.

h <r> CO• c*• o

"0a sr* o o

r-> o

rs. rH

pa o

T3m

(NrH

u

©

vo rH 3© Om

GO 0 c

VO o

flO T3m oinCN

vo o « m oo CO m •d m o Q om o

pa"0 omCM 00

|0

m rH tr

r o 00• r*• o

CQ 0

T3O o o

cr> o

<r -*

CO

-vU)MM CO•d Al

v-* •M % < Mc s i * J3

Pu.u

rH

w < d

0)> MZ 3

Q> T3

a

rJ •» 0) 0 u CO Cm O o c u P* •d 3 u H 0) o d w 4H

C/3 u» 0 5

4J CO o •H J= c •H 0) CO •H 4J *H 4J d z1 & 3

rH

0) >- -H a > dQ a* 0

cu ,3

u v- |H

H o o o O o o o O

T3 T3 T3 o c C c c M M M M

g

Distribution

of

Envelope

Noise

Level

Reduction »

AL.,dBft

PQ•dm3 1 15

dB

20

dB

25

dB. .

30

dB pa•dmn

pa° 0 o 9aI«n 1 9O

«M

pa•omCM 98 3S 3 S s «o 9 « m

•c

aa

•o

r-i 1

pa*omCM 98 3mcn 9 0 o <P

HC

—• C s 8 S o• O

03o , oua

CO•dsACM 1

pa•da

pa•dm

cn s § i s• 0 3 8

U1

sr •—

o* ! i m 3 . mm

pa•om

CMACM 1

COdmm

pa 0

•a 0 o 0_ 5

tn s'J «ff ipC

CO

•do 1 m

CQ°m | mPQ

•d | ovO 9O

CM1 m

rH 1

pa: « 0 “ § m — ^ •

co•do 1 m

co•din 1 mPQo • VO

CO•v , mvo

paT3m

rH1 orH 1

CO^ ° m<r

pa•do 1 m 3m l m

pa•do 1 vo

pa•d2 1

coo t1 >

i§ &4Jw 3 1

•< s 3 S’

•j < 3 C - a

H S* J .S

-> < j3 sJ s &

jS

OUTDOOR §ou o O

O

in

c»CO• o 0 . §

c*• c ow

fqO

10Nd 0

W)N

in o

•o &

3?

o'

Oin

CMrH• o Om

cn• o Om

CM

vO• o Om

GOo oina

rH omp^cnrH

roI

rHd

4HoH

as sr

O o 0

fj• M

cJ

a

Od

O

rH

C8

O > 35

rH

COTJin

inV

CO•d0vO1 mm

pa•dmvo1ovO 3Ol mvOco•dmI oCQ•d0001 m

CO•dm

cod,

00

30
Table

5.8.

Summary

of

Level

Weighted

Population

Changes

for

Example

Benefit

Analysis

M 00 *3-

m

H

m o

04 VO Ov CM in rH MT s r''. O r>» 00 UO >d-

»-3

a CM Mf vO o m o • <3 • • • • • • Pi o o o rH rH CM H

COZOu

OO.U

a o o o o rH vO

hJ

m in o m

O

<2 < i—i

05 rH i—i

VO o

oo CO

n oo LO

m • • • • • • o rH C0 vO O

rH rH

00 co CO 05 o oo vO rH 05 vO M W CM CO VO CM rH

Pcj Pj « o o CMm 05 CO

<3 • § a • • • • • . z m h4 o O o o o rH W H O C/5 C/5 Z < o O

04

O in in CO 00

M S S a in CM CM vO CO H W rj CO m CO I-*. <3 Z < o CM 05 VO vO 00 H • • • • • . Z o o rH «sT r-N o

rH

rJ

00 vO CM 00 rH rH

U

M VO

O vO CO CM

C_> &4 r> 00 CO CM CM CM 5 a CM CO m vO I''. a o3 rJ • • • • • . H < O o O o O o

C/5 Ooz O o m

m 00 00

Hm o r>. CM CO CO

HO rH vO >n oo 00 CO

CO PH 00 rHm rH oo vO

H & a • • • . • • X rJ o rH CM CM CO W <3M 00 05 CO VO & vO vO CM CM vO o S a r^» vO 00 05 m 00

rJ CM rH CM

m 00 < . • • • • • W o o rH CM CO >M

EH< O

E4 p_i H 2 o o m o o o

rj

a in

m CM o o o < < rH 05 rH CM C'. CM 00 CO m 00 >n m • • • • • • o rH CO VO o <r

rH rH

pi

mO in

Om o

<3 00 05 05

O o rH

W 05 05 05O o o >* rH rH rH CM CM CM

31
Table

5.9.

NoiseImpact

Estimate

for

the

No-Action

Alternative

M rsm CM st

H ^5

O 00 ON ON ON

a • rH • o • o • o • o H rH rH 1—1

rH o

St ON CO NO NO CM CM NO

NO CO ON

m

St rH CMm • • . • O rH CM CO o

i—i o St CM 00 CM M S'? NO St m St m z • • • . • < CM CM CM CM CM CO CO CO CO CO

Pioo

PH o o m o o S a m m CM o o

i—l ON rH CM rs < co CO m oo m • • . • • o rH CO NO o

rH

PQTJ o o O o O m CO 00 o m m a • • • • . m, CM sf o rH CM A rH CM CO m O m O m

oo ON ON

O o

ON ON o o

rH rH rH CM CM

32

2010

44.70

14.5200

32.48

4.8804

10.92
Table

5.10.

Noise

-Impact

Estimate

for

the

Example

Implementation

Scenario

for

the

MNCC

H n* CM CO rs SO

1—1 H 6^ o• m• CM• rH• n.• m• a rH on vO m -d- sf <] H M 00 m rH m o vO ON CM m i—i

<r 5 a fN o r"» oo m

CM Mf vO o lO o < • • • • • • O o o rH rH CM O Mf O lO ON SO O vO MT m sr -d- M • . • . • • H 5-3 CM CM CM CM CM CM S<

CO CO CO CO CO CO

oHoo < O o o o rH so m in o in O r'N rH ON rH rH sO O

00 CO

m 00m in • • • • • • o rH CO so o <r

rH rH

PQ o O o o O

O

m

a

•n CO oo o m t>. • • • • • • in, CM o rH CM «d- A rH CM CO «dpi m o m O m O

oo ON ONO o rH

ON ON ON

O o O

X rH rH rH CM CM' CM

33
Table

5.11.

Benefit

Estimates

for

the

Example

Implementation

Scenario

for

the

MNCC

d co O 73 • Hum < • W u 1 •u 4J o vD 00

cfl

O 0) o rs ON 00 o H O H Z . • • . • • 3 4-1 (X <4-i n3 O c H

P-i o O CO 00 rH rH

CM

d

•H

M

0)

M MM S'-S o CO CM LO NO G Z o CO r-', rH CO d < • • • • • • XlO o rH <1- m NO NO

PSoo c O *H o o st CM

M St

H <D

M o r> o rs

m NO o m M o o CO

g 5 z o o to CM o 00 • o • o • o • H • CM • CM o«

•H

<u o

00H o o CM CO CO CM

d

h o o o o o o d z • • • • • • x: < o o o o o o o

P4oop

d

H •rl Zo a) o

oo a. o o in o ON St d 3 z o o CM m ON CM d wj o o o o o H

xs < o o o o o a

CJ • • • • • • o o o o o o m o m o m o 00 ON ON o o M ON ON ON o o o M 1—i M CM CM CM

34
Table

5.12.

Presentation

Format

for

Final

Benefit

Estimates

(Data

Rounded

from

Table

5.11

Estimates)

r

a co O t3 • •H a) in

4J +J o vO 00 oo r^

Cfl

O <U o cr> 00 o HUH • • • • • . 3 4 S o o CO 00 <r iH

Q, M-l rt f-H CM O < H

fu

<U

M

60H o cn 00 CM sr S3 • • • • . • o rH sr m vO lO

a)

h

g § a H o

J3 < o lO rH rH rH <r o o m 04 O 00 • • • • • • o o o tH 04 CM

<u

O

60H § § 43 < U oo oo oo oo oo oo

<D

C

608343 < O

OO

OOo oo oo oo fA lO O m O m o < oo o\ O o rH w o> cr> o> o o o

rH rH rH CM CM CM

35
ALWP

, M

ALWP

, M

Population

Change

(b) Outdoor Noise Impact

(c) Indoor Noise Impact

Figure 5.1 Population Change and Level Weighted Population

for Years in the Time- Stream.

36
ANII

, %

ANII

, %

Population

Change,

M

(b) Outdoor Noise Impact

40 -i Curves Overlay Each Other

20 - No Action Alternative

MNCC Alternative

0

1980 1995 Year —

I

2010

(c) Indoor Noise Impact

12 t

10 -

8 -

6 -

4 -

2 - MNCC Alternative

0 -|

1980 1995 ' Year ~2010

Figure 5.2 Population Change and Noise Impact Index

for Years in the Time- Stream.

37
(a) Population Affected by MNCC Example Scenario

(b) Benefit of MNCC Based on Noise Impact Index

(c) Benefit of MNCC Based on Level Weighted Population

Figure 5.3 Population Affected, Change in Indoor Noise Impact Index, and Change

in Indoor Level Weighted Population for Years in the Time-Stream.

38
6 . CONCLUSIONS

A method is presented for estimating "benefits” related to implementing noise

control requirements in building codes. The model applies only to the benefits

resulting from the implementation of outdoor-to-indoor noise isolation. These

benefits may be directly related to costs estimated using a related model (1).

The benefit model allows the user to incorporate local data and alternative

noise isolation requirements appropriate to local conditions. Appendixes are included that describe the basic considerations for conducting the noise impact

estimates, estimation of noise isolation for existing construction, and a worksheet that is useful in conducting the noise impact estimates.

A detailed example is presented in section 5 that illustrates the steps and

considerations necessary to determine the benefits. For this example, a Model

Noise Control Code developed for the U.S. Environmental Protection Agency is

used to illustrate how one might incorporate the varied provisions of a candidate noise control code within the format of the benefit model.

39
7.

REFERENCES

1. Weber, S. F., Rudder, F. F., and Boehm, M. J., Method for Assessing Costa

of Noise Control Requirements in Multi-family Residential and Educational

Buildings , U. S. Department of Commerce, National Bureau of Standards,

Report NBSIR 81-2366 (1981).

2. Miller, N. P. and Schultz, T. J., Noise Control for Building Codes: Model

Noise Control Provisions , Bolt, Beranek, and Newman Report No. 37^,

prepared for U. S. Environmental Protection Agency, Office of Noise Abatement and Control (1978).

3. Harris, A. S., Keast, D. N., and Miller, N. P., Noise Control for Building

Codes : Implementation Manual , Bolt, Beranek, and Newman Report No. 3837,

prepared for U. S. Environmental Protection Agency, Office of Noise Abatement and Control (1978).

4. International Conference of Building Officials, Uniform Building Code , Whittier, CA (1979): Appendix, Chapter 35, Sound Transmission Control,

pp. 668-669.

5. Schultz, T. J., Miller, N. P., and Miller, R. L., Interim Report, Task I: Development of Noise Control Requirements for Model Building Code , Bolt,

Beranek, and Newman Report No. 3547, prepared for U.S. Environmental

Protection Agency, Office of Noise Abatement and Control (1977).

6. Anon., Guidelines for Preparing Environmental Impact Statements on Noise , Report of Working Group 69 on Evaluation of Environmental Impact of

Noise, Committee on Hearing, Bioacoustics, and Biomechanics, Assembly of

Behavioral and Social Sciences, National Research Council, National

Academy of Sciences, Washington, D.C. (1977).

7. Anon., Information on Levels of Environmental Noise Requisite to Protect

Public Health and Welfare with an Adequate Margin of Safety , Report 550/9-74-004, U.S. Environmental Protection Agency, Office of

Noise Abatement and Control (1974).

8. Part 150 - Airport Noise Compatibility Planning , U.S. Department of

Transportation, Federal Aviation Administration, Federal Reglster/Vol. 46,

No. 161, Monday, January 26, 1981/Rules and Regulations.

9. Yaniv, S. L. and Flynn, D. R. , Noise Criteria for Buildings: A Critical

Review , U.S. Department of Commerce, National Bureau of Standards Special

Publication 499 (1978).

10. Schultz, T. J., Impact Noise Testing and Rating - 1980 , Report No.

NBS-GCR-80-249 , U.S. Department of Commerce, National Bureau of Standards,

(1981).

11. Maurin, M. , Community Noise Impact Indicators: A Framework with Examples , Journal of Sound and Vibration, Vol. 7 9, No. 4, pp. 479-499 (1981).

40
12. Rudder, F. F., Ronk, L. , and Hutcheson, B., National Roadway Traffic Noise

Exposure Model . Prepared for U.S. Environmental Protection Agency, Office

of Noise Abatement and Control (1979).

13. von Gierke, H. E., Guidelines for Environmental Impact Statements with

Respect to Noise , Proceedings Noise-Con 77, NASA, Langley Research Center,

Hampton, Virginia, pp. 61-78 (1977)

14. Goldstein, J., Assessing the Impact of Transportation Noise: Human Response

Measures, Proceedings Noise-Con 77, NASA, Langley Research Center, Hampton,

Virginia, pp. 79-98 (1977).

15. Sutherland, L. C., Indoor Noise Environments Due to Outdoor Noise Sources , Noise Control Engineering, Vol. 11, No. 3, (November-December 1978).

16. AIR 1081, House Noise Reduction Measurements for Use in Studies of Aircraft

Flyover Noise , Society of Automotive Engineers (1971).

17. Anon., Home Sound Proofing Pilot Project for the Los Angeles Department of

Airports , Report No. WCR 70-1, Wyle Laboratories, El Segundo, CA (1970).

18. Sabine, H. J. , et al. Acoustical and Thermal Performance of Exterior

Residential Walls , Doors and Windows , U.S. Department of Commerce,

National Bureau of Standards, Report NBS-BSS-77 (1975).

19. Abramowitz, M. and Stegun, I. A., Eds., Handbook of Mathematical Functions

with Formulas, Graphs, and Mathematical Tables , U.S. Department of Commerce,

National Bureau of Standards, Applied Mathematics Series 55; Chapter 26,

Table 26.1 (1965).

20. Burington, R. S., Handbook of Mathematical Tables and Formulas , Fifth Edition,

McGraw-Hill Book Company New York, Table 18, pp. 424-427 (1973).

41

APPENDIX A

ESTIMATION OF NOISE IMPACT

This appendix describes the accepted methodology for estimating the impact of

noise on a population [6,7]. The methodology requires that the distribution

of population residing in a land area be known in terms of the average annual

day-night sound level. The methodology determines single number ratings that are used to characterize the level of noise impact. In the United States, two

common single number ratings are used for this purpose: 1) the Level Weighted

Population (LWP) and, 2) the Noise Impact Index (Nil). Reference 6 is a detailed description of the recommended documentation and methodology required

to determine the environmental impact of noise. This appendix includes

sufficient detail to quantify the noise impact as required for the benefit

model.

A. 1 POPULATION DISTRIBUTION WITH SOUND LEVEL

The most difficult data accumulation task is the estimation of the distribution

of population in terms of the average annual outdoor day-night sound level.

This distribution is denoted as p^ and provides the estimate of the population

exposed at a given outdoor day-night sound level, L^q. The methodology is

based upon the average annual day-night sound level at a person's place of

residence [6,7] even though a person will not spend the entire day at their

place of residence. These considerations are incorporated into the weighting

functions described in the following section.

For a population exposed to a range of day-night sound levels, the total

population exposed is determined from the population distribution, p^(L)

,

using the expression:

The form of Equation (A-l) is the most readily usable for practical

applications. For constant intervals, the above result is simplified to:

N

^exposed = ^ Pfc^ci^Lj.

i=l

(A-l)

where i denotes an interval of L^q

AL^ — L^+j — L^, dB

L ci = < Li+l + L i)/ 2 » dB *

N

^exposed “ ^ Pfc^d^AL

i=l

(A-2)

where AL is a constant.

A-l
The maximum value of AL recommended for evaluation of environmental noise

Impacts Is 5 dB [6]. If the entire range of sound levels used In equations

(A-l) or (A-2) encompasses the entire population, then the exposed population

equals the total population.

A. 2 WEIGHTING FUNCTIONS

Since the population under consideration Is exposed to a range of day-night

sound levels, It Is necessary to Incorporate this variation Into the noise

Impact analysis. This Is done by Introducing weighting functions that

attempt to determine an equivalent effect of noise at various levels. Considerable effort has gone Into developing weighting functions appropriate

to different categories of noise exposure [6,11,13,14].

For the purposes of the present model, a simplified weighting function Is

utilized. This simplified weighting function Is defined by the

relationships [6]:

vw - 0 LdnO - 55 (A-3a)

vw " < L

dnO

“ 55)/20 ’ 55 - LdnO - 85 (A-3b)

W

(/ LdnO ) - 1.5 LdnO - 85 (A-3c)

where L^nO is the outdoor day-night sound level.

To evaluate the effect of noise Indoors due to outdoor sources, It Is necessary

to shift the description of the outdoor L<jn scale to a scale of Indoor

values. As described In Appendix B, It appears reasonable to assume a shift

of 12.5 dBA corresponding to the center of the 10 to 15 dBA Interval of building envelope noise Isolation. Physically, this means that a residence located

in an outdoor environment of L^q 55 dB would correspond to an acceptable

condition with windows open for both outdoor and Indoor noise Impact estimates.

Denoting the indoor weighting function by WjCL), the appropriate form for the

Indoor environment due to outdoor noise sources Is:

VW " 0 L

dnl - 42 - 5 < A‘Aa)

WjCL^^j) " (Ldni “ 42.5)/20 , 42.5 ^ ^dnl 72.5 (A-4b)

W

I^ LdnI^

” 1,5 Ldnl - 72,5 (A-4c)

where L^ni is the Indoor day-night sound level due to outdoor noise.

The relationship between the outdoor day-night sound level and the indoor

day-night sound level due to outdoor noise is:

A-2
ALa LdnO ~ Mnl» dB (A-5)

where ALAis the noise level reduction provided by the building envelope.

A. 3 LEVEL WEIGHTED POPULATION

The Level Weighted Population or LWP is a single number defining the equivalent

or effective population exposed to a range of environmental noise levels. The

functional definition of LWP is [6,7]:

N

LWP = I Pjt (Lcl )W(Lci )AL (A-6)

i=l

where Pjj,(Lc^) is the distribution of population exposed to day-night

sound levels in the interval l>±+\ ~ L^ (see equation (A-2)),

W(Lci) is the weighting function,

Lci = ( Li+1 + Li)/ 2 »

The form of equation (A-6) assumes a constant interval, AL, of day-night sound

level. If outdoor day-night sound levels are appropriate, one uses the weighting function given by equation (A-3). For indoor day-night sound levels, one uses equation (A-4) for the weighting function to determine the LWP.

A. 4 NOISE IMPACT INDEX

The Noise Impact Index or Nil is a relative single number index useful in

comparing one noise environment to another [6]. The Nil is defined in terms

of the LWP and the population exposed as:

Nil = LWP/PeXp0ged. (A-7

)

The Nil value may be expressed either as a fraction or as a percentage.

A. 5 OBSERVATIONS

Formally, the distribution of population exposed at a given level of

environmental noise, p^(L)

,

has dimensions of "people per dB" as seen from

equation (A-2). For constant intervals of noise exposure, it is common practice

to aggregate data on the basis of the term p^(L c^)AL which has units of people.

Similarly, the dimension of the Level Weighted Population is "people" since the

weighting functions are dimensionless. The Noise Impact Index is a dimensionless number since it is the ratio of the LWP estimate to the population exposed.

A-3
One additional comment concerning notation is necessary. The benefit model

utilizes changes in population noise exposure to estimate benefits. In the

report, the notation AP exp is used to denote the change in population noise

exposure. To denote the LWP and Nil estimates for the change in population

exposure, the notation ALWP and ANII is used. The values of ALWP and ANII are not changes in these quantities but denote LWP or Nil estimates for the

change in population noise exposure, AP exp .
APPENDIX B

ESTIMATION OF OUTDOOR-TO-INDOOR NOISE ISOLATION OF EXISTING CONSTRUCTION

This appendix describes the basis for estimating the noise isolation of existing

construction. First, the method used to develop the distributions of envelope

noise isolation required for the noise impact worksheet is presented. These

distributions, or available local data, may then be used to estimate an annual

average or composite noise isolation distribution. The composite or average

distribution represents the weighting of the envelope noise isolation on the

basis of time to account for variations between the "closed window" and the

"open window" conditions.

B.l CLASSIFICATION OF SITE CONDITIONS

The noise isolation distributions developed for this model are based upon the

data of reference 15 and the assumption of a normal distribution of the

A-weighted noise isolation. Sutherland has developed the estimates for the

mean value and the standard deviation of the A-weighted noise isolation provided

by building envelopes [15]. These empirical data are divided into three groupings according to the dominant exterior noise source, the climatic region, and

the window condition. The groupings are as follows:

(1) Dominant Exterior Noise Source

(a) aircraft

(b) highway traffic

(c) average urban noise

(2) Climatic Region

(a) cold (Average January temperature below 2°C (36°F))

(b) warm (Average January temperature above 2°C (36°F))

(3) Window Condition

(a) closed

(b) open

The technical basis for this classification is the recognition that the

envelope A-weighted noise isolation depends upon the noise source (spectral

effects), the building construction, and the extent to which the shell is

open to the environment [15,16,17].

The dominant source of exterior noise given above recognizes the differences

in frequency content among different noise source categories. This grouping

accounts for the frequency dependence of the noise source, the envelope

construction, and the receiving room sound absorption.

B-l
The two categories for climatic region attempt to account for construction

differences attributable to the thermal performance of the envelope. These

differences may be attributed to both the thermal insulation (cavity filling,

storm windows, etc.) and to the sealing of gaps and cracks (air infiltration).

Both of these broad considerations affect the noise insulation of the envelope

[18]. The available data allow the estimation of the average noise isolation

only for the two categories of climate indicated. The term "cold" refers to

geographic areas for which the average January temperature is below 2°C (36°F).

The term "warm" refers to geographic areas for which the average January

temperature is above 2°C (36°F).

The effect of an open window or a closed window on the noise isolation of the

building envelope is obvious. Open windows in a room represent a lower limit

to the degree of noise isolation that may be experienced by the occupant. It

is necessary to include, open window conditions since it cannot be assumed that

the envelope will be sealed on an annual basis.

The first step in estimating the average noise isolation of existing

construction is to determine the dominant noise for the land area under

consideration. Once this is done, the next step is to determine the mean value

and the standard deviation of the noise isolation-weighted for climatic

conditions and assumed open/closed window conditions appropriate to the local

environment

B .2 MEAN VALUE AND STANDARD DEVIATION

Table B.l lists the mean value and the standard deviation for each of the site

conditions described above. These values must then be adjusted to account for

the climatic conditions and the open/closed window condition. Based upon the

average January temperature for the locality, the mean value and the standard

deviation for the envelope noise level reduction is selected. It is now necessary to estimate the percentage of time that windows are open and closed for

the locality for the entire year. This percentage of time is a local

consideration.

With these data, the average values of the mean noise isolation and the

standard deviation are obtained using the following expressions:

(A^A^avg = p 0pen ^^A^open + (1 “ ^open) ^^A^closed (B-l)

a avg

= °closed (B-2)

where p open is fraction of time that the windows are estimated

to be open during the year.

For example, assume that the site is exposed dominantly to highway noise and

that the appropriate climatic condition is cold. Further, it is estimated

that open window conditions exist for 50 percent of the year (closed conditions

apply to both heating and cooling time periods). From table B.l, the data are:

B-2
Table

B.l.

Mean

Value

and

Standard

Deviation

of

Envelope

Noise

Level

Reduction:

Existing

Construction

(reference

15,

and

as

noted) * •K •K G rH <1* iH O O O CU t> • • • • • ao

to <r •<r

O

co

K o <r rH v£> m o o TJ <3 • • • • • C tJ 00 CM CM o CM o rH iH rH rH rH rH

T3 * *

0) CM 00 Os

O o

CO c> • • • • • • O in <3- '3' m m (—

a

CO6s

r\w

nd <J so 'dO

O in o G X\ • • • • • • •H < sO CO m <r CO & CM CM CM CM CM CM O O

•H *rl P P G *rl T3rH

B orH fi •O

rH 6 03 O G O G O

•H

G

tH

O

UU

O ts o & O

po

•HP

0) PKWs

.5soQ

a)oP3O P

<PG

p

<pG

>s

cd 5o

cd CO P P Ds 6 G

G

CD

CO o o 43

G

G

pp bO 00 43

p P •H •H P P •HO

53

<3 <3 33 33 G> *

B-3

Assumed

Value
(ALA) 0 pen 12.6 dB

(ALA) c losed ~ 23.0 dB, °closed =

Then, the annual average mean value and standard deviation are:

(ALA>avg = (0.50) (12.6) + (0.50)(23.0) = 17.8, dB

°avg = ^.9, dB *

The reason for holding the standard deviation for the average annual condition

constant at the closed-window value will be discussed below in relation to the

estimate for the distribution of envelope noise level reduction.

B.3 DISTRIBUTION OF ENVELOPE NOISE LEVEL REDUCTION

It is assumed that the distribution of the values of the building envelope

noise level reduction is described by a Gaussian or Normal Distribution (19,20).

This distribution is completely described by the mean value and the standard

deviation. Further, the necessary numerical values are extensively tabulated.

The next step in determining the distribution is to aggregate the data in

intervals of A-weighted noise level reduction consistent with the intervals

used to define the distribution of population to outdoor day-night sound

levels. For the present model and consistent with recommended practice [6],

the intervals selected are 5 dB intervals.

For this data aggregation, it is necessary to recognize that the open window

condition represents a lower limit to the envelope noise level reduction. This

consideration is incorporated by assuming that the lower tail of the normal

distribution is totally aggregated in the interval 10-15 dB. Physically, this

attempts to approximate the lower limiting condition for the average noise

level reduction of the envelope with open windows.

The procedure used to aggregate data is best described by an example. First,

it is appropriate to define the terminology used. The normal distribution of

the envelope noise level reduction is defined as:

The aggregate or fraction of the distribution between two values of AL is

determined by the area under the p(AL) curve between the two values. The

functional expression is:

p(AL) = EXP [-£2 (AL)/2]//2¥ <t v

_ dV 6

(B-3a)

where £(AL) = [AL - (ALA) avg ] /aavg (B-3b)

AP = / p(x)dx,

*1

(B-4)

B-4
where p(x) is given by equation (B-3a), , £ 2 are the limits on the

interval.

For the normal distribution, the values of AP are determined using tabulated

values of P(£) as:

AP = PU2 ) " P(*i> (B-5)

where P( Jl) = /

A p(x)dx.

Values of P(£) are extensively tabulated (19,20). The above procedure is,

again, best illustrated by an example. The previous example estimated the

average annual mean noise level reduction as 17.8 dB with a standard deviation

of 4.9 dB. Table B.2 illustrates the steps necessary to obtain the distribution of the A-weighted envelope noise level reduction for this example. The

values of % are calculated using the definition in equation (B-3b) and the

values of (AL^) avg and aavg . The values of P(£) are obtained from tabulations

[20]. The remaining calculations are simple aggregations of the data. The

only special note to make is that the value of P(£) corresponding to AL^ = 15

is totally aggregated into the interval of 10-15 dB. The distribution obtained

in table B.2 is illustrated in figure B.l.

B.4 ESTIMATES OF NATIONAL AVERAGE DISTRIBUTION

The data in table B.l for the mean values and the standard deviation for the

six site conditions were used to develop distributions for the closed window

condition. The procedure described above was used to obtain these estimates.

The results are presented in table B.3. Further, distributions corresponding

to "national average" noise level reduction were also estimated. These estimates are based upon the methodology suggested by Sutherland [15]. To obtain

these estimates, it is assumed that 80 percent of the population lives in a cold climate with windows open 20 percent of the time and that 20 percent

of the population lives in a warm climate with windows open 50 percent of the

time. This population allocation and fraction of time for open windows is

suggested by Sutherland to be representative of the national conditions [15].

Equations (B— 1 ) and (B-2) are used with the data in table B.l to estimate the

composite mean noise level reduction, equation (B-l), and the standard

deviation, equation (B-2), for aircraft noise, highway noise, and urban noise.

The methodology described in section B.3 is then used to obtain the distribution for each category of outdoor noise. The results are presented in

table B.4. For the urban noise environment, Sutherland used an average mean

noise level reduction of 21 dB with a standard deviation of 7 in his development. The distribution corresponding to these data are also presented in

table B.4.

One may use the distributions presented in this appendix to estimate the indoor

noise impact for existing construction or develop distributions based upon

B-5
Table B.2. Example Calculation of Dis

Noise Level Reduction

tribution of Envelope

(ALa

) avg

17.8; 0 - 4.9

avg

L

i

£

i P(*±

) AP Interval

100AP

-5 -4.65 0.0000

0.0001

0 -3.63 0.0001

0.0044

5 -2.61 0.0045

0.0514

10 -1.59 0.0559

0.2284 10-15 28.43

15 -0.57 0.2843

0.2157

17.8 0 0.5000

0.1736

15-20 38.93

20 +0.45 0.6736

0.2556 20-25 25.56

25 +1.47 0.9292

0.0644 25-30 6.44

30 +2.49 0.9936

0.0062 30-35 0.62

35 +3.51 0.9998

0.0002 35-40 0.02

40 +4.53 1.0000

0.0000 40-45 0.00

45 +5.55 1.0000

B-6
Percentage

of

Construction

50

Mean = 17 . 8 dB

Standard Deviation = 4.9 dB

40 -

30 -

20 -

-i 1 1 50 60

A-weighted Envelope Noise Level Reduction, dB.

Figure B.l. Envelope noise level reduction

for data in table B.2

B-7
Table

B.3.

Percentage

Distribution

of

Envelope

Noise

Level

Reduction

for

Existing

Construction

a r^.

m rH OO no CN cn HC

um ON rH <n CN o o O cO • CD z in rH oo NO o o cn m

0) 4-1 Csl

m OJ CN

w (0a O •H z rH

CJ c

CO TO a rH t". in oo ON o *

4-i o 00

m

m NO rHm o a o • CN m m CN «H rH o m

rH cn cn rH CN

QW

coO

rJO

co§QZM&

0)

Efl •rHOz

>N

CJ ZOO

•rl a

NO o -a- o ON I''* NO 00 m m 00 m o o

rH CN

m in CN rH o m <r

rH cn cn rH CN I

rH

TO NO cn CNm cn 00 <n

rH rH ON 00 <r ON NO o o ON o

C_3

m rH 00 NO NO o o cn 'O’ CN cn CN CN

g r> rH rH

m ON cn

H 00 cn -d- ON CN 00

0)w o 00 ON 00 00 cn

d NO 'd- •H 0) CN cn rH CN o 4-1 z COa

4-» •H

4-4 rH

CO CJ

V4o TO 00 cn r«* o rH T—1

r>. <a- NO 00m ON 00 NO CN

•H • • • • • • • • • <1 CJ o NO cn NO <3- NO o n- m CN cn CN CN

i—i

nJ

C

a

mOmOm o m o

<3

n rH CN CN cn cn vf <r C3 •H

a CD 1 1 l l i i i cd 4-1 <3 4-1 o m o m o m o CD «d

£3 M

rH rH CN CN cn cn S3- S iH>

CD Q

T3

4-1 CO

B-8

Assumed

values
Table

B.4.

Percentage

Distribution

of

Envelope

Noise

Level

Reduction;

National

Averages

for

Existing

Construction

o o

t

iH

cn MT 00 <r Ml" d a) <r cr> rH m m o\ <o d «

43 -H cn <r i-m oo r>. rH o

M O ^ 55 rH CM CM rH CM

d Q1 o vO CO Cm o CO rH d m cr> o\ m rH CM CM o cr> o

43 •H • o rH O vO r«* CO O d o m

53 55 rH CO co rH CM

£ a> rH o Mt vO vO co o

45 CO O vO m d- CM rH o co CT> W) -H • • • • • • • • • •H O <r CO in CM o o o St

Ed 25 rH CO CO rH CM

44

4-1d

Ou

•H<

a) Mt o CO CM Ml- m CM w rH 00 CT1 rH O 00 rH m rH

•H • O CO m o \o CM rH o mT m

25 rH Ml- CM rH CM

rHt

mrH O

CM m

CM O

CO m

co oMf mMT d

• >

<u 1 1 l 1 1 1 1 d a) 44 O m o m o m O (U Q

d

w

H CM CM CO CO Ml- S •

CO

B-9

(1)

Sutherland's

estimate

-

Reference

15
local conditions. The national highway traffic noise distribution in table B.4

is used in section 5 for the example benefit analysis. If the closed window

conditions are used rather than a composite of open/closed conditions, one is

assuming that the existing construction provides the maximum possible noise

level reduction on an annual basis. The baseline noise impact estimate for

this condition will be less than an estimate assuming an open/closed condition.

As a result, the benefit (decrease in impact) of implementing noise control

requirements in the building code will also decrease.

B-10
APPENDIX C

WORKSHEET FOR NOISE -IMPACT ANALYSIS

Tables 5.5 through 5.7 illustrate a worksheet format for conducting the noise

impact analysis required to estimate the benefits of implementing noise control

requirements for the building envelope. This appendix is a blank copy of this

worksheet for users that desire to follow the format illustrated in section 5.

The worksheet format was first suggested by Sutherland [15].

C-l
Table

C.l

Blank

Work

Sheet

for

Noise-Impact

Estimates

CQ03

CQ CQ CQ CQ CQ CQ in 03 03 03 03 03 03 <1 in O m O m o o iH CM CM co co MT

CQ

CQ CQ CQ CQ CQ CQ

O 03 03 03 03 03 03 | O m O in o m m CM CM CO co m

CQ03 CQ CQ CQ CQ CQ CQ 03 03 03 03 03 03 nm m O m O in O l CM CO CO m om

CQn3 CQ CQ CQ CQ CQ CQ O 03 03 03 03 03 03 CO O m O m o m

in CO co

m

m

CM

CQ03 CQ CQ CQ CQ CQ CQ n

03 03 03 03 03 03

CM in

O in

O

mO o

CO

mm sO

CM

CQ03 CQ CQ CQ CQ CQ CQ o

03 03 03 03 03 03

CM

O in

O

mO in 1 m in vO vO

in

«H

CQ03

CQ CQ CQ CQ CQ CQ in 03 03 03 03 03 03 rH m O m O m O o m m sO vO

rH

-j<oe

T3

•J

p*<1

id

03 OJ

C

03

Om

CQ03osDI mm

C

03

hJ

Om

r*. m

CQ03mvOI osO

a

M

a c x

0) 03 Q) •J Pm< Om

CMSO c

03

•J

a

03

hJ om

CM

CQ03o

ooI in c

03 iJ

CQ03

*H

cd

O 4J oZ OH

CQ om 03 r—

cn

OfM. »H

CQ03 oin

CM in iH vO rHO CQ m 03 r*

oo

OvO o

CQ oin

03 CM m

sO

m o

CQ

Om 03 CO Oin o

CQ03 om

CM

in rHo

CQ03

O o o

<r

M

CQ P<

03 5

rJ

*> < C /•—

0k 03 M a c

H-l c X o

03 CD * -J Pm •u »H < cd

CD K- > 3 * 0

Q) 03 Cu

hJ * <3 o u C/3 p- 03 o O c u a 03 3 a X <U O <d w •u CO CiM sz c to u to o *H sz c CD GO •H u

*H •u cd 55 sz rH *H 1 to 3 <3 >v a >

CT3 <D o 0/ Q 3 Pm M u u u O o o o O o o o

03 03 03 03 c c c c M M M M

C-2
«" HBW14A (REV. 2-80) U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

2. Performing Organ. Report No. 3. Publication Date

NBSIR 83-2680 April 1983

4. TITLE AND SUBTITLE

Method for Assessing Benefits of Airborne Noise Isolation Requirements in

Residential and Educational Buildings

5. AUTHOR(S)

Fred F. Rudder, Jr.

6. PERFORMING ORGANIZATION (If joint or other than NBS. see instructions)

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No. AD-13-F-1-507-0

8 . Type of Report & Period Covered

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State. ZIP)

Environmental Protection Agency

Office of Noise Abatement and Control

Washington, DC 20460

10. SUPPLEMENTARY NOTES

| | Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here)

This report presents a method for estimating benefits accruing from implementing

acoustical performance requirements for new buildings. The method can be applied

to a wide range of environmental noise conditions and noise isolation requirements

for building envelopes. Benefits are estimated based upon the distribution of

population with outdoor noise level and the noise isolation provided by the

building envelope. A method is described for estimating noise isolation

performance of existing construction based upon local conditions.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

acoustical design; benefit analysis; building codes; model code; noise control;

noise impact; outdoor-indoor noise isolation.

13. AVAILABILITY

[~X| Unlimited

| | For Official Distribution. Do Not Release to NTIS

Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

[jJ5 Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

66

15. Price

$ 10.00

U S COMM- DC 6043-P80
.