A Life Cycle Assessment:
Comparing Fixed and ModularStructures. The right thing
to do—environmentallyspeaking—can also be the smart
thing to do—operationally andfinancially speaking. That isthe conclusion of a life cycle
assessment that compares theenvironmental impact of two
interior buildout options.

Research Summary / 2008

The first option consisted of fixed casework combined with architectural walls.
Both elements involved the construction of permanent, built-in millwork andsteel-stud-and-gypsum-board walls.
Researchers compared the first option against a second that consisted of modularcasework and modular walls. Once assembled, these elements have the appearance
and performance of permanent construction, but they can be rearranged without thewaste and mess of demolition.
In contrast to other similar studies, this research measured the effects of these twoapproaches on•

Global warming potential,•

Primary energy demand, and•

Waste generation.

While total cost of ownership typically considers purchase cost along with the ongoingcost of operations and utilities, this life cycle assessment (LCA) considered somethingelse: the impact on the environment of producing, installing, and reconfiguring orreplacing casework. It looked at multiple aspects of the product’s impact, from raw
materials to manufacturing processes. In addition, it considered the waste generated
from manufacturing, construction, and demolition.1
The assessment also took into account the impact to the environment on an ongoingbasis. What impact does casework have over time, and how might renovations andreconfigurations, for example, affect waste and energy consumption?
Data for the assessment was gathered from a number of sources. The model for theLCA calculations is Bluewater Health, a hospital organization in Ontario, Canada. Thishospital organization is undergoing a significant construction project, combining two
facilities under one roof for a total of five floors of new construction and five floors ofrenovation to the existing facility. Like a growing number of healthcare organizations, this
hospital counts environmental responsibility among its core values. Such organizations
have come to understand that a sustainable approach also impacts financial results. Yet
making a quantifiable case for instituting sustainable practices has been difficult.
Bluewater Health wanted an objective accounting of the environmental impact of its
purchasing decisions and ongoing operations related to casework. The hospital will
also be applying for silver LEED certification, so this data will be important through thesubmittal process. The analysis will be helpful, as well, for other organizations considering
LEED points and certification.
An independent research firm was engaged to conduct the LCA. The firm’s researchers
used installation measurements for the modular casework and modular walls based on
existing energy records and product specifications. Fixed casework statistics werecompiled from a database of information on materials. These statistics included details
such as costs of materials and construction and installation energy requirements.
A Life Cycle Assessment Research Summary / 2

The researchers then created the LCA model with a proprietary software system, whichassesses the cradle-to-grave environmental life cycle impact.

Facility Layout and Scope for the Life Cycle Assessment
The blueprints, specifications, and interior construction figures for the hospital became
the basis for the buildout scenarios. These included the following:•Exam rooms—246 treatment, isolation, and procedure rooms, each with similarfunctions and product layout•

Interview rooms—77 consultation, dictation, social work, assessment, and workrooms, each with similar function and product layout•

Nurse reception—46 registration areas•

Nurses’ stations—38, with different product and layout from nurse reception areas•

Pharmacy—1 large pharmacy•

Laboratory—1 large lab and 5 satellite stations•

Walls—6,117 linear feet, used in multiple areas

Rates of change were measured using three different scenarios: conservative, mid-point,and observed. Casework and walls have a high replacement rate in healthcare applications,so three scenarios were developed to determine additional materials required andwaste generated during remodeling and replacement. The scenarios include a rangeof replacement rates over a twelve-year time span, from slower change rates to more
rapid replacement rates.
Observed change rates are based on client experiences and field research. These change
rates were reinforced by the experiences of the VP of Redevelopment at Bluewater
Health. The conservative change rates were based on the minimal amount of change ahospital would make. Not all healthcare facilities change things as often as our observed
rates suggest, particularly facilities built with fixed millwork and conventional walls.
All three scenarios were used to measure material replacement, global warming potential,
energy consumption, and waste generation over a 12-year span. (See figure below.)Year 1
Year 2
Year 3
Year 4
Year 5
Year 6
Year 7
Year 8Year 9Year 10
Year 11
Year 12ConservativeMid-point
Observed
Replacement Scenario Replacement Scenario Replacement Scenario
Casework
Walls
Casework
Walls
Casework
Walls
5%
5%
5%
2%2%2%
2%
15%
2%
15%
2%
15%
2%
2%
2%
20%
35%
50%
2%
2%
2%
2%
25%
2%
25%
2%
25%
2%
2%
2%
2%
2%
2%
60%
50%
80%
50%
100%
50%
2%
2%
2%
2%
2%
2%
A Life Cycle Assessment Research Summary / 3

Casework: Initial Buildout Comparison

Comparing the Impact of Fixed and Modular Structures on the Environment

125%

Researchers analyzed three key areas of modular (modular casework and modularwalls) and fixed (millwork and fixed walls) structures. Each area relates to the effect100%of these structures on the environment.
75%
1. Influence on climate change using global warming potential (GWP) as an indicator.
· Measures greenhouse gas emissions, such as CO2 and methane. These emissions

50%

are causing an increase in the absorption of radiation emitted by the earth,25%

magnifying the natural greenhouse effect. Measurement unit = kg CO2 equivalent(1 kilogram = 2.2 pounds).
Fixed Modular

Fixed Modular

Fixed Modular

GlobalWarming
PotentialPrimary
EnergyDemandConstruction/
Manufacturing
Waste
Figure 2processes. Measurement unit = MWh (megawatt hours).

kg CO2 Eq

3. Waste using construction/manufacturing waste (C/MW) generation as an indicator.

Nurse Back Station
Pharmacy
Nurse Reception
Laboratory
Interview Rooms
Exam Rooms

500,000
400,000hydropower, and other sources, needed to produce the materials and manufacture
them in their final form. Takes into account the efficiency of electric power and heating

Casework: Global Warming Potential
600,000

2. Energy use using primary energy demand (PED) as an indicator.
· Measures total amount of primary energy extracted from the earth, including petroleum,· Measures waste generated during materials production, construction, and demolition.
Measurement unit = kg (1 kilogram = 2.2 pounds).

300,000

Finding #1—Impact Is Similar at the Outset, Then Diverges

200,000

At initial buildout, environmental impacts are similar for both modular and fixed casework.

100,000

Yet over their entire life cycle, modular casework and modular walls contribute less
Fixed Modular Fixed Modular Fixed Modular Fixed ModularInitial
Buildout

Conservative
Scenario

Mid-Point
Scenario

Observed
Scenario

to climate change, primary energy consumption, and waste generation when comparedto the impact of fixed casework and architectural walls. (See figure 2.)

Figure 3
The initial installation of modular casework generated slightly more GWP than fixed millwork.
This is due to the material makeup of modular products, primarily higher levels of plastic

Casework: Primary Energy Demand

3,000

MWh

4,000

and steel than fixed casework, which uses more wood. Within the first year, however,
fixed casework surpasses modular casework in its GPW impact.

Nurse Back Station
Pharmacy
Nurse Reception
Laboratory
Interview Rooms
Exam Rooms

Approximately 205,000 kg of CO2 equivalents are emitted from modular casework atinitial buildout. Just slightly less than 200,000 kg of CO2 emissions are emitted from fixedcasework. Contrast that initial comparison at 12 years: CO2 emissions from modular

2,000

casework have remained fairly static from initial buildout and are measured at approximately
220,000 kg of CO2 equivalents; fixed casework is measured at approximately

1,000

540,000 kg of CO2 equivalents, two-and-a-half times its initial measurement.
Primary energy demand represents the amount of energy consumed to produce theFixed Modular Fixed Modular Fixed Modular Fixed Modular

Initial
Buildout

Conservative
Scenario

Mid-Point
Scenariomaterials and manufacture them in their final form. The PED, for example, considers

Observed
Scenario
Figure 4
A Life Cycle Assessment Research Summary / 4

Casework: Construction/Manufacturing Waste

the energy associated with wood, from growing trees to processing the wood. PEDkg

measures both fossil and renewable primary energy.

Nurse Back Station
Pharmacy
Nurse Reception
Laboratory
Interview Rooms
Exam Rooms

28,00024,00020,000Modular casework always consumes less primary energy, from the initial buildout
through year 12 and for all replacement scenarios.

16,000Waste generation measurements considered construction and manufacturing phases as

12,000well as remodeling of the hospital. This assessment shows the advantage of modular

8,000casework over fixed: Since modular casework is 95 percent reusable, remodel waste is
negligible. On the other hand, 100 percent of fixed casework must be replaced.

4,000
Fixed Modular Fixed Modular Fixed Modular Fixed Modula

Initial
Buildout

Conservative
Scenario

Mid-Point
Scenario

Observed
Scenario
Figure 5

The conservative scenario measures remodel waste of modular casework at approximately
5,000 kg. By comparison, remodeling fixed casework results in nearly 90,000 kg sent
to the landfill. Construction/manufacturing waste is significantly different between fixedand modular casework. The conservative scenario measures approximately 6,000 kg
of modular casework waste versus approximately 19,500 kg of fixed casework waste.

Casework: Remodel Waste/Reusekg

150,000
12,000

Nurse Back Station
Pharmacy
Nurse Reception
Laboratory
Interview Rooms
Exam Rooms

The accompanying charts break down the environmental impact by specific areas. The
size and materials required for the laboratory represent the largest portion of modular
casework to GWP, PED, and C/MW, while exam rooms for the fixed millwork contributethe largest portion of GWP, PED, and C/MW. (See figures 3-6.)

9,000

Finding #2—Product Replacement Yields Dramatically Different Results

6,000

Consideration of product replacement yields dramatically different results when

3,000

comparing modular to fixed casework. Modular casework is reusable, keeping productreplacement low and landfill waste to a minimum.
Fixed Modular

Fixed Modular

Fixed Modular

Conservative
Scenario

Mid-Point
Scenario

Observed
Scenario

Because modular casework is reusable, only a small portion—5 percent—of new productFigure 6

is required during replacement. The same is not true for fixed casework: 100 percent
must be replaced, and 100 percent of the discarded product becomes landfill waste.

Observed Material Replacement Scenario Over Time

2.5

Material Replacement Factor

3.0

Material replacement is a significant factor in the life cycle assessment of the two
approaches in this study. The following chart highlights the difference in material

Fixedreplacement over a 12-year period. (See figure 7.)
Because fixed casework cannot be reused, 100 percent of it must be replaced for new
construction or any renovation, large or small. From an environmental perspective, that

2.0

means that 100 percent new products must be produced, impacting raw material demands
and energy consumption. It also means that 100 percent of the discarded product will

1.5

end up in a landfill.
1.0

ModularBy contrast, modular casework is highly reusuable. Over a 12-year period, modular

0.5

casework will use up to 151 percent fewer materials than fixed casework, primarily
Year1234567891011because new products don’t need to be produced.

12Figure 7

After only five years of use, a significant replacement increase occurs with fixed casework.
A Life Cycle Assessment Research Summary / 5

Walls: Initial Buildout Comparison

A similar jump occurs at the 10-year point. The modular casework, on the other hand,125%

stays relatively stable, requiring only a five percent replacement of product over the12-year span.

100%

Finding #3—Fixed Walls Have a Greater Environmental Impact
75%
Both modular and architectural walls had the largest overall environmental impact on50%

the hospital buildout in this study.

25%
However, modular walls have less impact in all environmental categories compared tothe steelframe-and-gypsum-board walls. Modular walls account for significant reductions
Fixed Modular

Fixed Modular

Fixed Modular

GlobalWarming
PotentialPrimary
EnergyDemandConstruction/Manufacturing
Waste

in waste and significant increases in change without product replacement. In addition,
the construction downtime in renovating spaces with architectural walls is considerable.
(See figure 8.)

Figure 8
The amount of modular walls specified for Bluewater Health is significant: 6,117 linear

Walls: Global Warming Potential
kg CO2 Eq

2,000,000

feet. This makes a compelling argument for using modular walls when environmental
impact is considered. Even a hospital that uses half as many feet of modular walls willrealize a positive environmental impact.

1,600,000
The differences between the two wall approaches increase when replacement scenarios
are considered. In all cases, the impact of modular walls from initial buildout through1,200,000

replacement is negligible. Fixed walls present a different picture. Environmental impact
nearly doubles from initial buildout to replacement for global warming potential, primary

800,000

energy demand, and construction/manufacturing waste. (See figures 9-12.)
400,000

Conclusion—Modular Casework and Modular Walls Reduce Impact
Fixed
Millwork Wall

ModularWall

Fixed
ModularMillwork WallWall

Initial Buildout

Replacement Scenario
Figure 9

Regardless of a hospital’s rate of change, modular casework and modular walls will
always yield better results for their impact on the environment when compared to fixedcasework and architectural walls. In addition, modular casework and modular walls
supports a hospital’s need or desire to change, whether due to expansion, renovation,

Walls: Primary Energy Demandor process improvements. Initial construction yields positive results as well.
MWh9,000

Modular casework and modular walls support change in another way: Reuse of products
positively affects the bottom line of a hospital organization. Fixed casework and architectural

7,000

walls essentially mean that a construction or renovation project is a start-over.
5,000
In fact, Bluewater Health, the hospital that serves as the model for this LCA assessment
is already using some of its purchased laboratory products in its existing lab. The hospital

3,000

was able to purchase products ahead of move-in, avoiding potential future price increases,and benefiting from the advantages of modular products in its lab processes. When

1,000

the time comes to relocate to the new laboratory, the products will go along. No waste
Fixed
Millwork Wall

Modular
Wall

Initial Buildout

Fixed
ModularMillwork Wall
Wallgenerated, no additional purchases required: The right way—and the smart way—toReplacement Scenario

operate a complex and environmentally responsible hospital.

Figure 10
A Life Cycle Assessment Research Summary / 6

Walls: Construction/Manufacturing Waste
kgNotes

140,000
1100,000

60,000Herman Miller provided the modular casework and wall products for this life-cycle assessment.
The modular casework products included the Action Office®, Ethospace®, and Co/Struc® systems.
In addition, Herman Miller provided modular walls from its Wall Alliance Partners, including
M-Wall and V-Wall® systems. This study compared these products to custom millwork andbuilt-in architectural walls. Therefore, the results of this research, while valid for these Herman
Miller products, should not be generalized to other modular furnishings.

© 2009 Herman Miller, Inc., Zeeland, Michigan® L is among the registered trademarks of Herman Miller, Inc.

20,000
FixedMillwork Wall

ModularWall

Initial Buildout

Fixed
Millwork Wall

ModularWall

Replacement Scenario
Figure 11

Walls: Remodel Waste/Reusekg

600,000
500,000
400,000
300,000
200,000
100,000
Fixed Wall
Replacement Scenario

Modular Wall
Replacement Scenario
Figure 12A Life Cycle Assessment Research Summary / 7