A111D5 IMSbOS

Center for

Building Technology:

a perspective - 1979

NBS i llBfiliiiiirijmiif^^^* ^^^^ PUBLICATIONS ! Illillllli^^^^^^^^ A11107 Et.Sb77

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

NBS SPECIAL PUBLICATION 439-1

WafionaT Bureaa of SJanda?^

MAY 1 0 1979

Center for

Building Technology: ^ a perspective - 1979

Center for Building Technology

National Engineering Laboratory

National Bureau of Standards

U.S. Department of Commerce

Washington, D.C. 20234

U.S. DEPARTMENT OF COMMERCE,

Juanita M. Kreps, Secretary

Jordan J. Baruch, Assistant Secretary for Science and Technology

U-S NATIONAL BUREAU OF STANDARDS

Ernest Ambler, Director

Issued May 1979
Library of Congress Catalog Card Number 79-600060

National Bureau of Standards Special Publication 439-1

Nat. Bur. Stand. (U.S.), Spec. Publ. 439-1, 31 pages (May 1979) CODEN: XNBSAV

U.S. GOVERNMENT PRINTING OFFICE

WASHINGTON: 1979

For sale by the Superintendent of Documents, U.S. Government Printing OfBce, Washington, D.C. 20402

Stock No. 003-003-02056-7 Price $1.40

(Add 25 percent additional for other than U.S. mailing)

.
Abstract

This report presents an overview of the

National Bureau of Standards Center for Building Technology's research, its accomplishments, and ongoing projects.

The mission of the Center for Building

Technology is threefold: 1) to advance building

technology by providing technical and scientific bases for criteria and standards that improve the

usefulness, safety, and economy of buildings; 2) to provide technical assistance to all sectors of

the building community; and 3) to develop

improved techniques by which the end-users in buildings, communities and industrial processes can conserve energy.

Keywords: Building safety, buildings, criteria,

energy conservation, research activities,

standards.
Introduction

About CBT Multidisciplinary Approach

The Center is part of the National Engineering

Laboratory, of the National Bureau of Standards;

it is located in Gaithersburg, Maryland, near Washington, D.C. The Center and its staff of

230—with expertise in more than 30 disciplines that affect the way buildings are designed and

built—exist to make buildings more useful, safer,

and economical.

The Center conducts programs of research

and technical problem solving. It produces

technical bases for building performance criteria to meet users' needs, and the methods of

evaluation, test, and measurement to assure build- ing performance.

The Scientific Approach

Building research offers much to improve

construction. Thus, at the Center, chemists work

to develop improved criteria for materials

durability or evaluate methods for preserving

historic monuments. Behavioral scientists look at the way sunlight and color affect the way

building occupants perform their daily tasks. They have found, for example, that illumination

standards are often set too high and that more

light does not always result in more production

or employee satisfaction. Here too, mechanical engineers examine

alternative building designs for energy

conservation and architects study the way that stairways are involved in the many stumbles and

falls that cripple the public each year. Next to

bicycles, stairs are involved in more accidents

than any other object. And structural engineers

investigate the way buildings fail: how, for example, reinforced concrete structures may fail because of winds, earthquakes, or by the

phenomenon called "progressive collapse,"

which has been implicated in the failure of some

buildings.

At CBT, recent advances in understanding

these problems have led to improvements in building codes and standards. But the projects

just discussed are rather isolated in their approach—with chemists in their bailiwick, and

architects, economists, psychologists, and

engineers in theirs.

More often, the Center's approach is multidisciplinary. Take the topic of windows, for example. The Center has studied them from

many viewpoints: How do they affect the design

of a building? Do they brighten the rooms? Do

they depress or uplift people? How do they

affect energy consumption? How do they keep

the heat in? Do they keep burglars out? Are they

worth the extra cost? How are they related to our sense of privacy? Researchers have also tested chemical coatings to reduce the heat loss through the glass. In this way, professionals from

many disciplines work together to improve the

fit between buildings and windows. This work

has resulted in widely used publications, one of

which, Windows and People, was reissued by the

French National Building Research Institution as Les Fenetres et les Gens.

»;«-M.».M»M***«»ai

Multidisciplinary window research activities address building

design, energy consumption, economics, security and their

effect on people's moods.

iv
V
Laboratory Facilities CBT and Community

One of the Center's major resources is its laboratories. Within its research faciUties, at Gaithersburg, researchers can subject a building

element or system to decades of seasonal climate

effects in "accelerated weathering" apparatus.

They can measure how well door bolts and locks

respond to the pressures that a typical 80 kg

burglar might be able to apply. Or they can measure how a steel beam or a concrete column

will respond in a 53 MN (12 million pound) test machine.

The Center also has seven environmental

chambers, the largest of which is 9x12x18 m

(30x40x60 ft), in which whole buildings have

been tested for the way they use or conserve

energy. These facilities can control temperatures

from -45° to 65 °C (-50 to 150 °F) and vary the

humidity as well. The chambers have been used

to evaluate refrigerator trailers, houses, mobile

homes, and military inflatable buildings.

The Center also maintains natural weathering

stations at sites from Alaska to Nevada and from

Baltimore to Puerto Rico. These have resulted

in specifications for building materials that are exposed to time, temperature, humidity,

industrial pollution, and sunshine (especially

ultraviolet light). The Center has a 15-meter-long

wall incorporating over 2400 building stones from around the world. It is used to study the

effects of natural weathering. The stones have

been in the wall for more than 30 years. In 1977

the wall was moved from the CBT's original site in Washington, D.C. to the new Bureau of

Standards, campus in Maryland.

The Center also works with other NBS

Centers on joint building research problems that use other special-purpose laboratories in fire, acoustics, instrumentation, etc.

Another aspect of the Center's impact on the

building community is visible from a brief look at the industry and the forces that work upon it. The construction industry is one of the largest in the United States—over 4 million workers. In 1977 new construction totaled more than $170

billion. During the past 5 years, spiraling costs increased the price of the typical new one-family

home 50 percent, exceeding substantially the

overall inflation rate. A host of factors affect the building

community. BuUding codes across the country,

building standards. Federal specifications and

regulations, economic and social changes,

individual and family preferences, and longstanding traditions within the industry itself, all affect the building marketplace. Added to these

factors are domestic and foreign building

innovations and research findings. The Center

considers the needs and effects of each of these

factors and responds to the most significant

problems with technology for their solution. To foster the application of this new

technology CBT is constantly interacting with

code groups, professional organizations such as the American Institute of Architects, and

industry and manufacturing groups. The Center

is able to reach this wide constituency by virtue

of its information dissemination programs,

participation at conferences, cooperative

research, and extensive staff interaction with over 200 domestic and international standardsgenerating groups.

vi
Organization

The Center's business is to advance building

technology. To do this, it constantly responds

with improved ways of observing, recording,

analyzing, and developing building performance.

All this is especially important now, when

demands for buildings are so severe. Work at the Center is carried out in four

laboratory-based divisions:

Structures and Materials

Building Thermal and Service Systems

Environmental Design Research

Building Economics and Regulatory Technology

As part of the National Engineering

Laboratory of the National Bureau of Standards,

the Center shares the Bureau's modern

laboratory complex in Gaithersburg, Maryland, a

short distance from the nation's capital. It also draws on the experience, skills, and special

laboratories of other NEL and NBS Centers. The work of the Center is an integral part of

the programs of NEL. A number of the activities cited here are conducted in and with the support

of other NEL units:

° Office of Engineering Standards

° Office of Energy Programs

° Center for Consumer Product Technology

° Center for Fire Research

° Center for Applied Mathematics

° Center for Electronics and Electrical

Engineering

° Center for Mechanical Engineering and

Process Technology

° Center for Field Methods

The studies described here represent only a sample of the Center's research. Additional

information is found in companion documents:

NBS Special Publication 446, Building

Technology Project Summaries, and NBS Special

Publication 457, Building Technology Publications. The Center invites direct inquiries on completed,

ongoing, and new research projects. However, some of the projects described here have not yet

resulted in a published document.

The chapters of this report were selected

merely to group similar projects, not to suggest

the way the Center is actually organized, which

is shown in the chart . Actually, CBT

pursues a set of goals and tasks that are developed at the Bureau level. CBT's research

falls into 3 goals—energy conservation, safety,

and economics—and 15 tasks that guide its research and the objectives of that research. By

contrast, the Center is organized into 19 programs, which in turn manage approximately

150 individual research projects. In all its longrange planning, the Center—like NBS as a whole—resolves societal goals, through its tasks,

into specific programs. In this way,

multidisciplinary coverage of existing problems

and criteria to base future research on are constantly reviewed.

Center research also receives oversight and

support from a number of panels of experts from

the building industry, coordinated by the

National Academy of Sciences/National

Research Council and the Department of

Commerce to name two.
Earthquake Hazard

Reduction

Construction Safety

Geotechnical

Engineering

Structural

Engineering

Building Materials

Building Composites

Center for Building Technology

Center Headquarters

Building

Thermal

and

Service

Systems

Division

Thermal Analysis

Thermal Solar

Building Energy

Criteria

invironmental

Design

Research

Division

Architectural

Research

Existing

Buildings

Mechanical Systems Sensory

Environment

Occupant Safety

Service Systems

Building

Economics

and

Regulatory

Technology

Division

Applied Economics

Rehabilitation

Technology

Solar Technology

Criteria and

Standards

Development

viii
Sponsors

The Center's programs are funded primarly by

other Federal agencies and by Congressional

appropriations through the Department of

Commerce. A limited amount of our research is funded by private groups. The organizations

who recently funded CBT are listed below:

Agency for International Development

Air Force Civil Engineering Center

Air Force Systems Command

American Society for Testing and Materials

Army Natick Development Center

Brick Institute of America

Community Services Administration

Consumer Product Safety Commission

Defense Civil Preparedness Agency

Defense Nuclear Agency

Department of Energy

Department of Health, Education and Welfare

Department of Housing & Urban Development

Department of State Department of Transportation

Dow Chemical Company

General Services Administration

Law Enforcement Assistance Administration

Maritime Administration

Masonry Institute of America

National Bureau of Standards

National Concrete and Masonry Association

National Park Service

National Science Foundation

Nuclear Regulatory Commission

Occupational Safety & Health Administration

Tri-Services Committee, Department of Defense

United States Postal Service

Veterans Administration

Throughout this document acronyms are used

for the various organizations working with CBT

in developing research criteria. Those used are:

ANSI American National Standards

Institute ASTM American Society for Testing and

Materials

DoT Department of Transportation

FAA Federal Aviation Administration

HUD Department of Housing and Urban

Development

MIT Massachusetts Institute of

Technology

NSF National Science Foundation
Disciplines

Acoustician

Architect

Architectural Engineer

Behavioral Psychologist

Bioacoustician

Ceramic Engineer

Chemical Engineer

Chemist

Civil Engineer

Code Analyst

Communications Specialist

Cost Engineer

Economist

Electrical Engineer

Electronics Engineer

Environmental Engineer

General Engineer

Geologist

Geotechnical Engineer

Housing Technologist

Hydraulics Engineer r Industrial Engineer

Materials Engineer

Materials Scientist Mathematician

Mechanical Engineer

Metallurgist

Operations Research Analyst

Physical Scientist Physicist

Psychologist

Public Administrator

Quality Control Specialist

Safety Engineer

Sanitary Engineer

Social Psychologist

Sociologist

Standards Engineer

Structural Engineer

Urban Planner

X
Energy and Buildings

CBT research findings discovered that significant energy savings were possible by reducing nozzle size of oil furnaces.

Energy is the one CBT research topic that

attracts the most pubhc attention. Why? Because

one-third of all the energy used by the United

States is consumed by commercial and residential buildings. In new buildings about 40 percent of

that energy could be saved; in existing buildings

about 25 percent could be saved. Put another

way, out of every 10 barrels of oil that are now

burned, one and a half barrels are wasted

because of inefficient building practices. Similar

savings are possible in many countries around

the world.

Overall, the goals for the Center's energy

research are to minimize the life-cycle energy

costs by strengthening energy conservation

standards, promoting the concept of an energy

budget for building designs, and improving

design and component criteria. Energy costs have become so large a factor in personal finances that the press across the nation

has referred to CBT's energy studies over 1700

times in the first 6 months of 1978. The focus of

much of this attention is CBT's economic

analysis that shows how insulation and storm

windows may save up to 50 percent or more in energy consumption during the winter. The

consumer guide, Making the Most of Your Energy

Dollars, based on CBT data, has become a bestseller and has been the basis of many feature

articles. Center research into the properties and

performance of many types of insulation has also attracted wide attention: topics such as moisture

migration, urea-formaldehyde foam, and foamed

plastic insulation are examples of national issues that have begun to be resolved as a result of

CBT research.

A Center contractor went to New England to examine how oil furnaces were used and

maintained outside of the laboratory. What they

found was surprising. Almost all furnaces had oil nozzles that were too large. An immediate

savings of about 4 percent of the winter's fuel

bill was thus available to homeowners who

replaced their furnace nozzles. Further savingsup to 30 percent-are available by replacing

defective oil burners. Even simple tune-ups were shown to result in savings of about 3 percent per

year.

1
Support to the Department of Energy to develop part-load performance-test methods for

residential heating and cooling equipment also provided a solid basis for developing part-load

performance data for heating, ventilating, and

air-conditioning systems for commercial

buildings.

Even greater savings are possible from

incorporating energy-saving ideas into the design

of new buildings. The Center published Design

and Evaluation Criteria for Energy Conservation in New Buildings, which in turn was used by the

American Society of Heating, Refrigerating, and

Air-Conditioning Engineers (ASHRAE) and the

Illuminating Engineering Society, to develop a new national standard on energy conservation

for builders. The consulting firm of Arthur D.

Little Associates, Boston, estimated the use of

this new standard would not only save 60

percent of the energy used in office buildings,

but would also reduce initial costs. It seems that the additional costs of insulation and glazing are more than offset by the savings in heating and air conditioning equipment.

The GSA's Norris Cotton Building, an office building in Manchester, New Hampshire, is the

first in a new generation of energy-conserving

buildings, designed from the beginning with

energy efficiency in mind. It has a cubical shape

(for the smallest heat loss), a windowless north

wall, and tiltable solar panels on the roof. The

Center is monitoring the building for its energy

consumption through a sophisticated system of

instruments. It continuously tracks the variables

that affect the energy use of the building. That means continuous measurement of 300 items in 3 categories: the weather, the building, and the

way the building is operated. The data are presented to the Center's multidisciplinary

evaluation team in the form of profiles of energy

use for heating and cooling on an hourly, daily,

weekly, monthly, or yearly basis.

Also, CBT is designing and constructing new

equipment to measure the thermal performance

of insulating material and large scale composite

wall, floor, ceiling, and roof sections. This

equipment will be used to support the

development of test procedures and performance

standards on insulating materials.

2
Solar Energy

The performance of an evacuated tube collector is being monitored to develop test methods for solar collectors.

Solar energy performance standards are one of

the primary objectives in the National Solar

Heating and Cooling of Buildings Program. This

work is vital to the growth of a viable solar industry as well as to our national energy goals.

By 1985, it has been estimated by the

Department of Energy (DoE) that solar heating

and cooling of buildings could displace the con- sumption of nonrenewable energy sources by 3 quads (1.5 million barrels of oil per day).

CBT's approach has been to evaluate the state- of-the-art in solar heating and cooling and to analyze all available technical data, including

information from DoE and the Department of

Housing and Urban Development (HUD)

residential and commercial solar heating and

cooling demonstration projects. Solar systems

studied include active, passive, and hybrid types.

Components studied include collectors and

thermal storage devices. Based on the

information obtained, CBT has and is continuing

to develop the necessary performance standards

as well as testing standards to evaluate system

and component performance. These cover

thermal efficiency, degradation, durability and

reliability, as well as safety.

Functional materials evaluated are cover

plates, absorptive coatings, sealants, insulation,

hoses, metallic and nonmetallic containment

materials. For example, the Center is producing

the technical basis for standards on the

performance and durability of components of

solar collectors. Glass cover plates, rubber seals, coupling hoses, and caulking are targets vul- nerable to the weather. If they degrade, so does

the performance of the solar collector. Recently, the American Society of Heating,

Refrigerating, and Air-Conditioning Engineers

(ASHRAE) used CBT-developed test procedures

for thermal performance as a basis for two

recently adopted standards. The standards are ASHRAE 93-77, "Methods of Testing to Determine the Thermal Performance of Solar

Collectors," and ASHRAE 94-77, "Methods of

Testing Thermal Storage Devices Based on

Thermal Performance." Similar work is now

underway for solar domestic hot water systems

and passive components.

3
Building Economics

Life-cycle costing (LCC) is not a new

technique. It is often thought of as a tool the

Defense Department uses to procure tanks,

airframes, or submarines. Lately, however, the

energy crisis has stimulated renewed consideration of LCC when we consider the way

our buildings use energy. The basic concept of

LCC is simple. It considers not only the initial investment costs, but also the operating and

maintenance costs of a building during its lifetime—hence the name, life-cycle costing.

Many other areas of building economics also receive special attention at the Center. For

example, the Center has looked into the costs of

natural disasters, such as floods, hurricanes,

tornadoes, and earthquakes. The economics of

protection against building collapse have been

studied to determine the benefits and costs

resulting from larger investments in safety. CBT

has also written guidelines on how to measure

the economic benefits and costs of solar energy

systems.

The most influential of CBT's economics work

made it possible for homeowners to easily

calculate the most effective amounts of insulation

for their homes. The technical data were

reported in a formal NBS publication. Retrofitting Existing Housing for Energy Conservation:

An Economic Analysis. The consumer booklet.

Making the Most of Your Energy Dollars, is credited with transferring the guidelines to the

general public. Since the publication of these two

documents, which recommend higher levels of

insulation on the basis of cost-effectiveness,

major insulation manufacturers have begun

marketing larger insulation batts.

4
CBT economists, serving as technical advisers

to DoE, have prepared life-cycle costing

guidelines for use in the Federal Energy

Management Program. The guidelines were

required by Executive Order 12003, "Relating to Energy Policy and Conservation," signed by

President Carter in July, 1977. The guides will be used by all Federal agencies in developing

their 10-year plans, annual reports, and budget

estimates for meeting the energy consumption

goals of the Program: to reduce energy

consumption in all existing Federal buildings by

20 percent and in all new Federal buildings by 45

percent by 1985. The Center has also formulated an

experimental design for analyzing the costs of

alternative methods for reducing the lead-based

paint hazards in housing. Based on this design, an

econometric model was developed that permitted the most cost-effective combination of

lead paint abatement methods to be identified. The lead paint hazard raises the equally

important question of the rehabilitation of older

buildings. Is there, for example, a rational way of

deciding whether to abandon or to rehabilitate a building? There are many factors that affect this decision, one that is vital to landlords, tenants,

and cities. All of them are now being studied in projects that constitute the first comprehensive

look at the choice between tearing down or improving the nation's building stock. At present, economic research at the Center

continues with studies of the economic efficiency

of alternative masonry construction, and the

question of whether the energy price used in determining energy performance standards

should be the actual market price or a price

adjusted by corrective factors called Resource

Impact Factors.

5
Rehabilitation

CBT is developing evaluation methods and minimum performance standards for rehabilitating existing buildings. The national concern for conserving resources and for fighting inflation has prompted the

Center's work on rehabilitation of buildings and

homes. Rehabilitating older homes in inner-city areas thought to be past their prime will be a more labor-intensive operation, will bring jobs to lower-skilled workers, and will contribute to the

revitalization of neighborhoods.

The Center's work in this area begins from the

point of view of the building regulator. Major

thrusts are aimed at: providing technical support

to NCSBCS and to the model code organizations

in developing building code provisions and

regulatory processes for the State of

Massachusetts on a pilot basis, collecting data on

the regulatory process for existing buildings in major U.S. cities; developing technical

evaluation manuals for existing buildings; co- sponsoring a National Conference on the Regulatory Aspects of Building Rehabilitation;

sponsoring MIT to develop technical data on an

investigation of regulatory barriers to the re-use of existing buildings; and publishing an NBS

report, Assessment of Current Building

Regulatory Methods as Applied to the Needs of

Historic Preservation Projects, developed by

the National Trust for Historic Preservation.

Research will lead to the development of test methods, analytical procedures, performance

standards for building materials and systems, and

evaluation techniques. Studies will be carried out

to obtain a more effective understanding of "life style" as well as "life-safety" concerns. Decision

tools are being developed to assure wise and

cost-effective decisions regarding rehabilitation

of buildings. Factors include design aspects,

economic aspects, adaptability for re-use, and

neighborhood and site influences. This work

presents a unique opportunity for CBT to advance building technology into the arena of

existing buildings to address a national need

issue.

6
Materials Studies

Evaluating equipment for detecting moisture in roofing insulation. One of the distinguishing traits of modem

man, according to philosopher Eric Hoffer, is that he worries about the maintenance and

durabihty of his monuments. The Egyptians

didn't worry about theirs, nor did the Romans or

the Druids, so what is left of their cultures today

is purely through chance. At the Center, and at other national building research institutions worldwide, research continues in hopes that society can prolong the lives of historic structures so they may be part of the legacy to

future generations.

CBT's preservation research has involved

paints for the White House, and has provided

guidance on maintenance aspects of the

restoration of the St. Louis courthouse, and the

preservation of several historic forts and adobe

dwellings—all under the auspices of the National

Park Service.

Materials research at the Center is multidisciplinary, employing the talents of researchers

in the fields of materials science, chemistry,

physics, metallurgy, and civil engineering.

Together, the materials team has developed new

ways of solving problems related to performance

and durability.

About $16 billion is spent on concrete in the U.S. each year and the equivalent of about 20

million tons of coal is used in the manufacture of

cements. In many design situations, concrete is overdesigned to ensure that safety factors allow

for the large uncertainties in estimating the

quality of concrete and its service life. The

Center is working to improve the state-of-the-art of predicting the performance of concretes in normal and severe environments, including the

performance of concretes in which a portion of

the cement is replaced by energy-conserving

substitutes such as "fly ash." The $5 billion that the country spends on built- up roofing each year offers a significant area for savings if roof life can be prolonged and failures can be avoided. Among other capabilities, the

Center has a hail gun which it developed to simulate the effects of hailstones on roofing and

walls. The Center has also developed test methods for the flow properties of roofing

asphalt. The performance of energy conserving

roofing systems and nondestructive detection of

moisture within roofs, are other important areas the Center is investigating.

7
Building and Community Acoustics

CBT research is developing design criteria to limit noise

intrusion in and around buildings.

Tomorrow's cities and urban regions will be even more densely populated than today's. As a

result, noise management will become a vital public service. The primary beneficiaries of this work will be the users of buildings and

communities; the primary targets of CBT's

building and community acoustic efforts are the

building and site designers—architects and city

planners—and the public agencies that regulate

those buildings and sites. Noise management at the early stages of the basic design provides

enhanced acoustical performance at little or no

cost. Early action will prevent the extremely

costly corrective measures needed in already-completed buildings. Take the case of aircraft noise: DOT/FAA estimates $200 million is needed to soundproof just the existing schools and hospitals near airports. Fortunately, the interdependencies

between acoustical and energy performance means that these retrofits would yield over $1.7

million in energy savings annually and over $3

million annually in productivity enhancement.

The Center's approach will define the

interdependencies among acoustical requirements

of buildings and sites and other needs (optimal resource use, occupant satisfaction, and worker

productivity) affecting decisions about land-use,

site planning, and methods of building

construction and operation.

CBT staff have been working closely with

several Federal agencies to develop and improve

acoustical criteria for buildings. A recent study

undertaken for the Environmental Protection

Agency evaluated the basis for existing

acoustical criteria for buildings.

8
Environmental Design

What levels of light do people need for performing various tasks? What size, shape,

shading, and glass tint make windows "work"

better? What color give unambiguous emergency

warnings? Building designers need reliable answers to questions like these. In fact, the

choice of light levels and design of windows

strongly affect energy conservation as well. In

response, the Center has developed a method to measure effects of illumination levels on human

performance. Another study addressed the

psychological reaction to environments with and

without windows and the impact of windows on

energy-efficient buildings. Still another codified

color nomenclature and classification with the

revision of the widely-cited Color: Universal

Language and Color Names. The results of such

work are vitally important in safety engineering

and in the manufacture of building products.

Similarly, the Center is investigating how

humans behave during fires. Related studies

looked at how the crowds in stadiums use exit ramps and stairways under normal conditions.

Thus, in this area CBT is developing the

technical basis through laboratory and field research for producing, testing, and

recommending revisions to building performance

criteria in illumination, visual communication

signs and symbols—building security, interior space requirements, noise and building

circulation. Complementary research is underway in the development of field measurement systems to enable these factors to be evaluated under the actual operating

conditions.

Since most buildings are intended to support

human activity, effective building research is, ultimately, people-oriented. This relating of

human behavior to physical environmental

conditions underlies environmental design

research at the Center.

Studies of pedestrian movement lead to improved criteria for stair and ramp design.

9
Safety and Security

Accidents in building construction make this occupation three times more hazardous than the

average job. Deaths or injuries to workers in concrete construction, trenching, and excavation

have established these as priority areas for improved safety. The Center is developing

technical criteria and guidelines for safer work

activities as the basis for new regulations for the

Occupational Safety and Health Administration.

The Center previously developed guidelines for the design and use of guardrails that protect

workers. Labor and management groups are

assisting CBT in its tasks. Today, CBT is developing a model for predicting lateral forces on bracing elements in shallow trenches,

measuring construction loads on concrete construction, improving safe practices in concrete

falsework, and cooperating with the ANSI A10 committee in developing improved safety standards. What is a slippery floor? The Center is engaged in measuring slipperiness and has

designed and constructed a portable slip tester

to be used in floors, stairs, bathtubs, and

swimming pools. This device has been adopted

by the American Society for Testing and

Materials for use in a standard for measuring the

slip-resistance of bathtub surfaces. Millions of Americans live in mobile homes.

But are they a good investment? Are they safe? How do they compare with conventional

houses? CBT's research studies are aimed at making mobile homes safer, with particular

reference to wind loading; energy conserving; more durability and liveability; and more

economical. CBT's environmental chambers for

testing the energy efficiency of mobile homes

were featured in a national magazine article. Analyses of the methods used by burglars

show that the majority involve low levels of

skill. Thus, a great reduction in burglaries could

Performance criteria were developed for doors to better resist forced entry.

be achieved through only slight improvements in door and window quality. Through extensive

laboratory test development, CBT has prepared

voluntary security standards for doors and

windows; these were published by the U.S. Department of Justice. The test methods for the

door standard have also been adopted and

published as an ANSI/ASTM standard, after a demonstration program proved their worth at a HUD public housing project.

10
Mechanical Systems

Testing and rating methods are being developed for heating, ventilating and air conditioning equipment.

Automated heating, ventilating, and air- conditioning systems can control building

comfort, energy use, fire alarms, security alarms,

maintenance alarms, and several other functions.

Their application has greatly increased since the

energy cost rise of 1973. Even though all the

systems supplied by different manufacturers use

the same basic components, different techniques

in system design and application make the

selection of the most effective system quite

complex. CBT is studying system performance

and developing a model purchase specification

based on its experience with installing and

evaluating the computer control system for the

NBS laboratory site. Equipment selection and energy conservation

decisions require that information supplied to consumers be based on the part-load and seasonal

performance of equipment as actually used in

service—to relate that use to costs, energy

consumption, and efficiency. The Center is developing dynamic test procedures to define

this performance for residential heat pumps,

furnaces, boilers, and air conditioners. These

procedures are the basis upon which all appliances will be labeled to indicate their operating costs. This will allow consumers to make purchases on a life-cycle cost basis rather

than a first-cost basis only.

The energy crisis and the advances in the solid

state electronics field have brought a multitude

of new household thermostats into the

marketplace. Many of those thermostats are of

radical new design and claim significant energy

savings. To protect the consumer, the Center is developing a standard test procedure by which

all residential thermostats may be evaluated. This

will become the model procedure for the

industry.

11
structural Studies

CBT is developing technical criteria for updating construction safety standards such as scaffolding and safety nets.

The Center has measured the forces and

effects of wind on buildings at sites around the

world. The findings are used to verify analytical

techniques and wind-tunnel modeling for improved design criteria. The Center was asked

by the Australian government to review plans

for rebuilding Darwin after its Christmas Eve

hurricane of 1974. CBT researchers are also cata- loging the probabilities of extreme winds at various locations worldwide to develop

improved risk-mapping methods. Researchers at the Center are among the first to study the cross- wind response of tall buildings in high winds. A

similar study is concentrating on the accuracy

and reliability of wind-tunnel modelling of

building designs. As an example of technical

support in a program designed to continually

upgrade standards, CBT developed criteria for wind loading of mobile homes. The criteria account for regional differences in wind climate,

the dynamic action of wind gusts, and anchoring

of mobile homes.

It is well recognized that many of the factors

that affect structural performance are random.

To simplify the design process for different construction materials and make it consistent from a

reliability viewpoint, current trends point toward

the development and use of probabilistic limit- states design. Toward this end, structural

reUability studies that integrate statistical data on

resistance and loads have been virtually completed for reinforced concrete and currently are

in progress for masonry and wood structures. The Secretariat for ANSI Standard Committee

A58, "Building Code Requirements for Minimum Design Loads in Buildings and Other

Structures," is held by CBT. This widely

respected standard provides the mechanism for implementing the above research on loads and

reliability and provides the opportunity for CBT

staff to collaborate with universities, designers,

and code officials on a problem of national

significance. As a result of these studies, a

revised load standard approved through ANSI

voluntary consensus standard procedures will be

issued in 1980 and a Loads and General Design

Guideline will be published shortly thereafter. The properties of unreinforced masonry walls

have been studied to better define their resistance—for example, to increase safety in earthquakes. In another study, CBT is attempting

to consolidate all the fragmentary standards that now cover masonry construction. Other work is progressing on fire-resistant structural designs,

the improvement of honeycomb cores in construction components, and an investigation of

the vertical support members of the Alaska

Pipeline, among numerous other projects.

12
Geotechnical Studies

A new research area at the Center is devoted

to the interaction of buildings with the earth

they rest upon. That is, the stability of sites and

foundations. A series of projects in the area of

geotechnical engineering study trenches and

excavation safety, foundation failures and testing,

and the danger of building in areas prone to mine

subsidence.

Over 80 percent of all foundations in the U.S.

are designed on the basis of results from the

internationally used Standard Penetration Test. As part of a program to study in situ

measurement of soil properties, CBT is measuring the hammer energy delivered to the

standard penetration test to determine the

parameters which affect test results. These data

have been misinterpreted because of differences

in energy delivered by different types of

equipment. This test plays a major role in U.S. foundation design practice and is currently being

used to determine the liquefaction of potential

sites. A draft standard for foundations and

excavations is being developed in cooperation

with the American Society of Civil Engineers.

13
CBT researchers studied the effects of mine

subsidence on structures and utiHties and

prepared guideHnes for the construction of

housing in subsidence areas. CBT, together with

the University of Texas, conducted a workshop

to determine research priorities in the field of

soil dynamics (geotechnical earthquake

engineering).

Problems associated with the protection of

construction workers against collapse of trenches

and excavations were studied by CBT

researchers. Measurements of transient forces on

crossbraces in shallow trenches are now in progress. The state of knowledge and available data on

the capacity of soil anchors used to tie down

mobile homes against wind and flood loads has

been studied. A field study is now in progress to determine anchor capacities for various soil conditions and flood loads that need to be

resisted by mobile home foundations.

14
Plumbing and Electrical

Shower heads are being tested to develop criteria and test methods to reduce water use.

This program is developing the technical basis for standard test methods, inspection techniques,

and criteria to reduce the 100,000 electrical system failures per year that cause building fires; to attain component and system standards to meet the goal of national water conservation; to provide new plumbing pipe sizing designs; and to

establish sensor accuracy to better control the

interior environment.

The Center is involved in developing criteria for more water-conserving and materialsconserving techniques. For the former,

researchers are determining requirements for evaluating the efficiency rating of water devices

through standardized test procedures. For the

latter, work in reduced-sized vents is exemplary.

Savings, which come from the use of smaller

pipes (about two commercial sizes smaller, on

the average, but up to five sizes smaller in some

instances) and fittings and reduced installation

costs, are estimated at about $100 per house. An

economic analysis indicated potential annual

nationwide savings of between $60 million and

$200 million (assuming, in the case of the latter figure, full implementation and 2 million housing

starts—the 1977 level).

Similarly, the Center has developed

performance criteria for plastic pipes and vacuum drainage systems for the Department of

Housing and Urban Development. The Center

also developed hydraulic performance criteria and submitted recommendations to the American

National Standards Institute committee and other

standards groups for a performance-based

standard under development for the National

Plumbing Code.

Among the Center's special laboratory

facilities is a five-story plumbing research test tower. This tower is used to study the

performance of plumbing systems and

components and is equipped with an automated

hydraulic load controller and display system.

The equipment permits preprogramming of test loads and its display board can be wired directly to show failure points and other operational

characteristics within the system. Researchers can then adjust experiments to determine the

parameters for optimal performance of the

system. Test data are fed into a small computer

compatible with the NBS central computer.

In the area of electrical distribution systems,

there is a need for a thorough review of the

National Electrical Code to study its effectiveness and adapability to new energy

sources, energy conservation controls, and new

thicknesses of thermal insulation that may bury

attic wires. Other innovations, such as flat conductor cable, are also being studied.

15
Disaster Mitigation

CBT is developing criteria for improving building performance during disasters.

NBS has the responsibiUty under the

Earthquake Hazard Reduction Act of 1977 to develop and improve seismic design and

construction provisions for incorporation into

codes and standards. The President's National

Earthquake Hazards Reduction Program

requires NBS to conduct research on

performance criteria and supporting

measurement technology for earthquake resistant construction.

After many disastrous earthquakes around the

world, a team of engineers from CBT is among

the first on the scene. Their objective is to assess examples of successful and unsuccessful building

performance to improve future design and

construction practices. Researchers are sometimes asked to help assess which buildings should

be evacuated and which can be safely re-entered. Two Center engineers were on the first struc- tural research team to reach Managua,

Nicaragua, after its 1972 earthquake. Similar help was sent after the Guatemalan earthquake of

1975, the Italian earthquake of 1976, the

Romanian earthquake of March 1977, and the

Japan earthquake of June 1978. The Center has

also been asked to give technical assistance after such domestic disasters as: the Alaska flood,

Hurricane Camille, the Lubbock tornado.

Hurricane Agnes, the St. Louis Federal Records

Center fire, the Fairfax, Virginia, high-rise

building collapse, and the West Virginia cooling

tower collapse.

16
Every disaster is different, and can teach

researchers anew how buildings perform. Based on these field studies and laboratory research,

the Center developed a method for surveying

and evaluating buildings for their resistance to earthquake forces. Tentative provisions for the

development of seismic regulations in buildings were prepared by the Applied Technology

Council, California, under NBS and NSF

sponsorship. But what of buildings now

underway or soon to be constructed? For

example, the largest earthquakes in U.S. history

struck near New Madrid, Missouri, in 1811- 1812—in an area seldom thought of as a potential

site for earthquake trouble. If it were to recur

today, property damage losses could well total over $50 billion, with massive human suffering

and numerous lives lost. The Center's five-volume report—resulting

from an Agency for International Development

sponsored research on improving the design

criteria for low-rise buildings to better resist hurricane wind—was being used in India to rebuild the area following their November 1977

cyclone. And CBT's wind engineering program

will redefine the basic design wind speeds in coastal and hurricane sensitive regions.
International Studies

Researchers perform post-disaster surveys of building failures in foreign countries to improve building practices.

Building research has application not only

domestically but also the world over. The

Center participates in a great many international building research projects. Such

work usually falls into two categories:

individual agreements to jointly pursue research

goals with the building research institutes of

another nation (such as France's Centre

Scientifique et Technique du Batiment

(CSTB), United Kingdom's Building Research

Establishment, or the Institute for Research

Technology in Brazil); or, research aimed at specific building problems of developing nations. This latter category recognizes the fact that the same technology that could improve a high-rise

in Chicago could also be put to good use in strengthening buildings in the tropics.

For example, the Center has long been

involved in investigating the response of

buildings to high winds. This work has led to updating standards for predicting wind pressures on new buildings. Eat it also contributed to improving low-cost housing designs in windprone nations worldwide. In Jamaica, the

Philippines, and Bangladesh, studies were made

of how local construction techniques survived

wind storms. The job for the researchers was to develop easy-to-do and practical steps, making

use of local materials, that would improve the

endurance of a home in such a storm. The Center's wind project has attracted a wide

international readership. The Center's 16-mm

sound movie of the results of its Philippine highwind study was awarded a first prize at a 1976

international film competition in Rome.

18
The wind project also developed materials for

local builders, homeowners, and the general

public. These were set forth in 43 Rules: How

Houses Can Better Resist High Wind, which

presents guidelines for the home builder by

making the technical results more understandable

and useable. Also, a poster that depicts damage

due to wind and some common mistakes in construction and placement of homes was

produced. It illustrated, graphically, ways of

reducing damage and injury carried by wind.

Most important, it told where to go for further

information.

Results from this project have become a part

of the Philippine National Building Code and are expected to be used by Jamaica in revising its building codes. The results will also have an impact on codes and standards dealing with

winds loads in the United States. Other

countries, such as the United Kingdom,

Australia, and Japan, are expected to use the

study results. CBT's cooperation with building research

groups in other industrialized nations is a prudent

attempt to avoid costly and time-consuming

duplication of effort. It is also an admission that no country holds an edge over the the others in building research. Some nations, however, do

have acknowledged expertise in certain areas: England, for community energy systems;

Sweden, for rehabilitation and recycling of

buildings; Israel, for water-conserving plumbing

systems; and Russia, for the analysis of blended

cements. CBT, in turn, has a similar catalog of

expertise that is attractive to building ministries

in other countries. The Center has also sponsored guest researchers from other

countries, France and Brazil among them.

Over the years, the Center has established ties with two dozen national building research

groups and is a full member of the Conseil

International du Batiment pour la Recherche

I'Etude et la Documentation (CIB). CIB's major

objective is to encourage and stimulate

international cooperation in the gathering,

refinement, and dissemination of building

research information. Recent collaborations

between CBT and CIB have covered plumbing

and energy conservation. Likewise, the

International Organization for Standardization

(ISO) is comprised of the national standards

bodies of some 80 countries. The work of ISO is aimed at worldwide agreement on international

standards for the purpose of the expansion of

trade, the improvement of quality, the increase

of productivity, and the lowering of costs. CBT

is very much involved in ISO work and

currently is contributing by taking part in the

discussion on the establishment of an

international standards center. CBT also participates in the Reunion Internationale des

Laboratories d'Essais et de Recherches sur les Materiaux et les Constructions (RILEM), an

international nonprofit association governed by

Swiss Law. Its aim is to constitute a medium of

exchange and of communication of scientific experience, especially the experience acquired by

the study of materials and building elements, by

observation, by tests in the laboratory and in-situ, and by research.

19
Codes and Standards

In the United States, the authority to regulate

the construction and use of buildings rests with

the State governments because the Constitution

does not assign that authority to the Federal

government. Until recently, however, the States have not exercised that authority, but have

deferred to local governments. Even though

many States have enacted statewide building

code programs in recent years, most legal

building codes are the laws of cities and towns,

and each one has the potential to be, and often is, unique. This tremendous diversity has been

decried by many as a millstone around the neck

of the construction industry, impeding

innovation and efficiency. While there are unifying influences underway that tend to reduce

the inconsistency and diversity of building

regulations, the fact remains that there are a

great many diverse building codes and standards. Where building regulations exist—and nearly all cities with a population over 10,000 have them

they exert strong control over how buildings are designed and built and what they are built with.

Because of this, building codes have a tremendous influence on our built environment

and thus on society as a whole.

Because the drafting of a building code is usually far too big a job for any but the largest

cities to undertake, model codes are in widespread use as the basis for most legal codes.

Individual jurisdictions often adopt one of the

models as their legal code; but frequently the

models are amended, so diversity still exists. The

model code associations are not the initial authors of all things in their codes. Indeed, the

bulk of technical provisions governing buildings

today come directly or indirectly from hundreds

of national standards that deal with engineering

practice, material specifications, and test methods. These standards are produced by over

a thousand different committees in hundreds of

different organizations.

Although the Center does not have regulatory

power, it participates actively in the code change

process and assists in developing a better understanding of our regulatory system to bring

about improvements for the public benefit. It provides technical advice to various Federal

CBT technical data provides a basis for building code

provisions.

agencies as well as State and local governments

and to voluntary standards groups. The Center

participates in the Model Codes Standardization

Council and provides special technical support to the National Conference of States on Building

Codes and Standards. CBT technical findings

draft regulatory criteria and technical guidelines

and criteria—are transferred directly to standards-setting committees in industry,

government, and to the model code groups. CBT

is also providing significant assistance to the U.S.

building community as it enters the metric

system of measurement.

20
Better Building Performance:

an Afterword

The Center's programs have developed to address all aspects of the environments men build

to meet societal needs:

° usefulness - the degree to which the

building serves its intended

function, the productivity

and delightfulness of the

environment provided.

° safety - the degree to which the

building mitigates natural and

manmade hazards to life and

property.

° economy - the relationship between

usefulness and safety

performance qualities of

building materials,

components, and systems and

their costs.

Only the second of these usually is a subject of

regulations. Primarily, the role of the Center is to provide decision makers in the building

community with rational bases for their decisions

in all three areas. An additional area of knowledge is explored

by the Center to fulfill this role. That is performance in the building process by building owners, occupants, designers, manufacturers,

fabricators, builders, regulators, and maintainers.

The Center provides them with performance

criteria and measurement technology to strengthen their activities.

21

<r U. S. GOVERNMENT PRINTING OFFICE : 1979 O - 291-027

i

I