Modular Construction & LEED

Modular Building
and the USGBC’s LEED™
Version 3.0 2009 Building Rating System
Prepared for
___________________________
T his report was prepared at the request of the Modular Building
Institute (MBI). It is intended to provide the membership
of MBI and other interested stakeholders with an overview
The Modular Building Institute of how the Modular Building Institute’s current practices
944 Glenwood Station Lane, Suite 204 and products can benefit from an awareness of the US Green
Charlottesville, VA 22901 Building Council’s Leadership in Energy and Environmental
Design (LEED™) Building Rating System. Information in
this document represents the author’s best attempt to align the
modular building industry with the Prerequisite and Credit
requirements imbedded in LEED. The interpretations herein
are those of the author and do not represent any official posture
of the US Green Building Council beyond those contained in
the Reference Guide to LEED for New Construction and Major
Renovations, Version 3.0, 2009.
Prepared by
It is recognized that modular building components and finished
___________________________
modular building units can be a part of any LEED design and
Robert J. Kobet, AIA, LEED AP construction effort. This report is limited to LEED for New
Sustainaissance International, Inc. Construction and Major Renovations, applied to commercial
5140 Friendship Avenue
construction, and LEED for Schools. The literature shows
Pittsburgh, PA, 15224
there is a growing awareness of the environmental benefits
and of modular construction in the residential sector. LEED for
Homes has emerged from its pilot phase and is currently in use.
137 Golden Isles Drive
Most of the comments and observations of this report can be
Hallandale, FL., 33009
applied to LEED for Homes.

Rev 2 | 6.09

Modular Building AND the USGBC’s LEED™ Building Rating System

Modular Building and the USGBC’s LEED™ Building Rating System
Introduction

T
he emergence of green building as the The purpose of this paper is to align the interests
combination of environmental stew- and goals of the Modular Building Industry with
ardship and economic opportunity has LEED Version 3, 2009, or LEED V3. The newest
served to drive several related construction in- version of LEED reflects the US Green Building
dustries toward market opportunities provided Council’s desire to accomplish the following:
by the green building movement. Conversely,
existing industries with products and practices 1. Normalize the scoring of the various rating
that resonate with the tenets of sustainable de- systems to a 100 point system.
sign and development and green building have 2. Give greater emphasis to those credits that
naturally benefited from the increased aware- stress energy conservation, renewable energy
ness and market opportunities inherent in this systems and the US Green Building Council’s
paradigm shift. The US Green Building Council drive toward carbon neutral buildings.
with its Leadership in Energy and Environmen- 3. Introduce a new Credit Category that rewards
tal Design (LEED™) building rating system has LEED project teams for successfully achiev-
assumed a leadership position in the US and ing credits dealing with regional priorities. In
abroad and is serving as the preeminent organi- Version 3 (V3) these are referred to as Region-
zation identified with and instrumental in green al Priority credits or “RPs”.
building market transformation. This posture
is underscored by the international adaptation In LEED Version 3.0, 2009 the allocation of
of LEED as the most popular and best-known points between credits is based on the potential
third party verified green building rating system environmental impacts and human benefits of
currently in use. Federal, State and local build- each credit with respect to a set of impact catego-
ing construction requirements and development ries. These impacts are defined as the environ-
practices now commonly reference or require mental or human impacts of design, construction,
LEED certification. Its influence continues to operation and maintenance of buildings. These
grow. At the USGBC Greenbuild Conference in include such things as greenhouse gas emissions,
Boston in November 2009, it was declared that the production of toxins, fossil fuel use and water
the USGBC is the fastest growing not for profit and air pollution. The US Green Building Coun-
organization in history. In response to market cil used parameters from the US Environmental
opportunities and the desire to respond to stake- protection Agency’s TRACI environmental im-
holder desires to make LEED more specific to pact categories as the basis for weighting indi-
building applications, LEED has evolved from vidual credits. TRACI was developed to assist in
a single LEED for New Construction and Major the evaluation of life cycle assessment, industrial
Renovations to the following family of LEED ecology, process design and pollution prevention.
products: LEED 2009 also takes into account weightings
developed by the National Institute of Standards
LEED for New Construction and Major and Technology. These standards were used to
Renovations compare one credit to another and assign a rela-
LEED for Commercial Interiors tive value to each.
LEED for Existing Buildings
LEED for Core and Shell LEED for New Construction and Major Renova-
LEED for Schools tions Version 3.0, 2009 is based on Credit Cat-
LEED for Homes egories with the same titles. As mentioned the
LEED for Neighborhood Development Regional Priority category has been added. The
Market Sector Rating Systems Credits and attendant points in LEED 2009 are
o Multi Buildings and Campuses now:
o Retail
o Healthcare Sustainable Sites (SS)
o Laboratories (1) Prerequisite and (26) possible points
Water Efficiency (WE)
(1) Prerequisite and (10) possible points

Rev 2 | 6.09 www.modular.org :: 2009 :: The Modular Building Institute


Energy and Atmosphere (EA)
(3) Prerequisites and (35) possible points
Materials and Resources (MR)
(1) Prerequisite and (14) possible points Contents
Indoor Environmental Quality (EQ) Introduction..............................................2
(3) Prerequisites and (15) possible points
Innovation Design (ID) Modular Building
(0) Prerequisites and (6) possible points and the LEED Building
Regional Priority Rating System.........................................5
(4) possible points
Sustainable Sites
This results in an arithmetic tally of 110 possible and Modular Building...............................6
points. However the nature of LEED in practice Water Efficiency
holds that achieving all 110 points is not pos- and Modular Building...............................8
sible; they are available but subject to the influ-
ence of project context, design and construction Energy and Atmosphere
choices and design and construction process and Modular Building.............................10
variables. Project context is simply a matter of
where the project is located. A project pursu- Materials and Resources
ing Sustainable Sites Credit 1 – Site Selection is and Modular Building.............................14
awarded a LEED point if the site selected does Indoor Environmental
not violate any of the site selection criteria. An Quality and Modular Building................18
.
example of design and construction choices is
achieving the requirements for Materials and Innovation and Design
Resources Credit 4.1 – Low Emitting Materials, Process and LEED................................24
Adhesives and Sealants by not exceeding the al-
lowable volatile organic compound (VOC) lim- Regional Priority....................................26
its. Design and construction processes are such Conclusions...........................................27
activities as those necessary to attain Materials
and Resources Credit 3.2 – Construction IEQ Sustainable Sites
Management Plan Before Construction. The MATRIX.................................................28
many benefits of modular building do not enable
the finish project to escape the influence of site Water Efficiency
selection. However, the economies associated MATRIX.................................................30
with manufacturing in a closed environment Energy and Atmosphere
with stringent material use and quality control MATRIX.................................................32
capabilities makes modular building an ideal
choice for manufacturing energy, material and Materials Resources
resource efficient structures. MATRIX.................................................34

In LEED 2009 the threshold levels for LEED Indoor Environmental Quality
certification are: MATRIX.................................................36

Innovation and Design
Certified 40 – 49 Points MATRIX.................................................38
Silver 50 - 59 Points
Gold 60 – 79 Points Regional Priority
Platinum 80 or more Points MATRIX.................................................39

The goal of most stakeholders using LEED as
a building rating tool is to achieve the highest
LEED certification rating possible. Certification

www.modular.org :: 2009 :: The Modular Building Institute Rev 2 | 6.09


is the process by which a project team fulfills the aged to visit www.usgbc.org and www.gbci.org
prerequisites and earns sufficient credit points regularly to obtain the latest information on the
to reach one of four certification levels: Certi- LEED family of rating systems and the attendant
fied, Silver, Gold or Platinum. This process is LEED exam.
explained in complete detail in the Reference
Guides issued for each of the LEED rating sys- For the purpose of this study modular building is
tems as well as on line at www.usgbc.org. considered to be one of the following:

In the LEED certification system prerequisites Prefabricated building components, parts,
are activities or processes that must be done but pieces and sub assemblies assembled under
for which no points are awarded. Credits are controlled conditions and shipped to become
pursued as a matter of choice for which points part of a larger, primary building project. They
are awarded if the requirements of the credits may represent a small portion or a significant
are achieved. In LEED for New Construction contribution of the completed project but they
and Major Renovations Version 2009 there are are not considered to represent the finished
nine Prerequisites, one hundred Base Points, six habitable project in and of themselves.
Innovation in Design Points and four Regional Whole building units prefabricated under con-
Priority Points. trolled conditions and delivered to the construc-
tion site. These units are commonly identified
In LEED 2009 there are nine prerequisites and as those that are manufactured and assembled
seventy-nine possible points. The other LEED off site then shipped in whole or in part to the
building rating systems vary but most carry a construction site to complete a finished unit.
similar category / credit / point structure. The Usually they are erected on a foundation that is
reader is referred to www.usgbc.org for a more constructed ahead of delivery then assembled
complete description of each. in large sections or as largely completed units
less final systems connections to civil infra
A LEED Accredited Professional is anyone who structure and site utilities.
passes any of the current exams administered
by the Green Building Certification Institute Modular building applied to prefabricated com-
(GBCI), an organization allied with the US- ponents can be used in any building type LEED
GBC to provide professional development and is used to certify. It is important to note that if
LEED accreditation testing. After March 31, prefabricated modular components are used in
2009, individuals wishing to take the LEED AP the context of a larger building they must meet
exam will have to register for the LEED Ver- the LEED criteria that apply to them but also are
sion 3 exam. The GBCI will offer an entrance subject to the LEED rating system as it relates
level exam designed for individuals who are al- to the finished building type under consideration.
lied with the green building movement and the The individual components or subassemblies do
application of LEED but who may not need or not, in themselves, receive LEED certification.
desire to be tested for a high degree of techni- In the case of modular building units the com-
cal proficiency. A LEED AP Plus exam will be pleted unit may be the subject of the LEED rat-
available for individuals who anticipate par- ing application and certification effort and may
ticipating in the LEED certification process in a ultimately be the finished project that receives
more involved and technical capacity. For the LEED certification.
purpose of clarity buildings undergo a certifi-
cation process. Individuals who pass a LEED
accreditation exam become LEED Accredited at
the level of the exam they take and are entitled to
use the credential LEED Accredited Profession-
al Associate or LEED Accredited Professional,
LEED AP. The US Green Building Council
and the LEED building rating system continue
to evolve. Because of this the reader is encour-



Modular Building and the
LEED Building Rating System

I
n order to better understand what affects a modular building’s potential for LEED certification
and the way LEED certification scores are compiled it is necessary to consider the following
observations and conditions that inform the LEED certification process

LEED prerequisites and credit opportunities fall into three broad areas of
concern:
Context and Community Connectivity. These issues are largely a function of where the project is located.
They are not specific to modular building practice, processes or products. A project using modular building
techniques is subject to the opportunities or limitations inherent in good site selection the same as any
other project.

Architectural, Engineering and Construction Choices. These are the decisions that comprise how a proj-
ect is designed and constructed. Material selection, construction techniques, building systems selection,
installation and controls and most other decisions that pertain to building envelope, mechanical, electrical
and plumbing systems and space conditioning are in this category. Modular building offers significant
opportunities for environmental stewardship, economic opportunity, LEED certification and market pen-
etration in this area. Material handling, optimal construction conditions and environmental control during
construction all can contribute to attaining LEED credits and attendant points. Much of this report is
focused on this area.

Construction Administration and Processes. These include such activities as commissioning, construction
waste management, maintaining superior interior air quality during construction and before occupancy and
measurement and verification. Like Context and Community Connectivity, Construction Administration
and Processes are not specific to modular construction. Instead they are prerequisites and credit oppor-
tunities that are common to all construction and the project as a whole. However, commissioning can be
done under optimal factory conditions, construction waste management and material recycling can occur
under tight factory control and construction documentation can be very efficient. All of this can make LEED
credit compliance and documentation very efficient.

The LEED tables and attendant narrative that er self evaluate projects. The letters stand for
follow at the end of this document are provided “Yes”, “Maybe” and “No”, referring to the
to illustrate how modular building practices and likelihood of each of the credits in the project
products align with the goals of high perfor- under consideration. They are provided only as
mance green building and the USGBC’s LEED a guide to assist the reader in understanding the
building rating system. Each is presented as a application of LEED and how it can be used to
reflection of current industry practice. The “Y evaluate different products and projects.
M N” columns are provided to help the read-

LEED Evaluation Matrix - Modular Building Institute

Credit Description Y M N Submittal Requirement Modular Building Issues

Attaining the Sustainable Sites Credits is largely a matter of project context. They are not specific to the physical qualities or attributes of modular building with the exception
on SS Credit 7.2 : Heat Island Effect - Roof

Construction
www.modular.org ::Activity Pollution Modular Building Institute path. drawing and narrative.
Prereq. 1 2009 :: The Required Erosion and sediment control
Confirm compliance
This is a general requirement for most building projects. Modular units need to
Rev 2 | 6.09
be placed within the guidelines of good site management practice.
Prevention


Sustainable Sites
and Modular Building

T
he Sustainable Sites Category in LEED Even though the majority of the credits in the
2009 has one Prerequisite and twenty six Sustainable Sites category are not a function of
possible points. The additional weight construction techniques it is important for stake-
given to credits and points in this category are in holders in the modular building industry to un-
SS Credits 2 through 4.4, none of which have a derstand the overall intent and requirements of
direct bearing on modular building. each credit. Proper siting or placement of modu-
lar units can contribute to improved daylighting,
SS Credit 7.2: Heat Island Effect – Roof is the natural ventilation, better storm water manage-
only Credit in this category that is a matter of ment, more efficient site lighting and a host of
design and construction of a modular unit. The other sustainable design and development im-
Prerequisites and all other credits in this cate- provements that contribute to a more energy, ma-
gory are a function of context and community terial and resource efficient project.
connectivity. In order to achieve SS credit 7.2
modular construction must meet the require-
ments for solar reflective index or SRI in the
roofing material(s) used over 75% of the roof
area. These are SRI of 29 for roof areas of more
than 2 in 12 and SRI of 78 for roof areas in ex- MBI 2009 Awards of Distinction:
cess of 2 in 12. Green Building Winners
Modular construction may also have unique at-
tributes regarding SS Credit 6.1 – Site Develop-
ment - Protect and Restore Habitat. Option One
in this credit applies to construction done on
green fields or sites not previously disturbed or
developed. It rewards construction techniques
that limit site disturbance and keep disturbed ar-
eas to within the areas immediately adjacent to
the building footprint. The intent of the credit is
to stay within forty feet of the building perimeter,
within ten feet of sidewalks and utility trenches
serving connection of ten inches in Diameter or
less, within 15 feet of trenches with larger utility Waldorf School, Charlottesville, VA
connections and within twenty five feet of areas
intended to remain permeable.

Because modular components and complete
modular building units are fabricated off site
and delivered by a variety of over the road trans-
port it is possible to achieve tighter site control
and less disturbed area in the project perimeter.
Industry representatives need to coordinate de-
livery of modular components with contractors
to insure the site tolerances for SS Credit 6.1 can
be maintained.

SS Credit 9 – Site Master Plan and SS Credit 10
– Joint use of Facilities are specific to LEED for Jim Russell Racing Drivers School, Sonoma, CA
schools and are not reliant on either conventional
or modular construction for credit compliance.



How are modular structures more beneficial?
Modular construction techniques have been shown to be inherently advantageous in 7 major areas:

Less Materials Waste – Pre-fabrication makes it possible to optimize construction materials pur-
chases and usage while minimizing on-site waste and offering a higher quality product to the buyer. Bulk
materials are delivered to the manufacturing facility where they are stored in a protected environment safe
from theft and exposure to the environmental conditions of a job site.

Less Material Exposure to Inclement Weather – Many of the indoor air quality issues identified in
new construction result from high moisture levels in the framing materials. Because the modular structure
is substantially completed in a factory-controlled setting using dry materials, the potential for high levels of
moisture being trapped in the new construction is eliminated.

Less Site Disturbance – The modular structure is constructed off-site simultaneous to foundation
and other site work, thereby reducing the time and impact on the surrounding site environment, as well as
reducing the number of vehicles and equipment needed at the site.

Safer Construction – Modular construction is a safer alternative. Conventional construction workers
regularly work in less than ideal conditions dealing with temperature extremes, rain, wind, or any combina-
tion of natural conditions. This, by its very nature, is a much more challenging environment to work safely
in. Additionally, the potential for injury including falls, the most common work site risk, is much higher. In
a factory controlled setting, each worker is typically assigned to a work station supplied with all the ap-
propriate equipment needed to provide the safest work environment possible. Off-site construction also
eliminates the hazards associated with materials, equipment and an incomplete construction processes
typical of construction sites that can attract curious and unwelcome “visitors” (i.e. students on a school
expansion project).

Flexibility – When the needs change, modular buildings can be disassembled and the modules relo-
cated or refurbished for their next use reducing the demand for raw materials and minimizing the amount
of energy expended to create a building to meet the new need. In essence, the entire building can be
recycled in some cases.

Adaptability – Modular buildings are frequently designed to quickly add or remove one or more “mod-
ules” minimizing disruptions to adjacent buildings and surroundings.

Built to Code With Shorter Build Times – The bottom line is that with modular construction you can
get a facility built to the same local codes with construction quality as good as or better than a comparable
site built building in much less time. Additionally, the abbreviated construction schedule allows you to get
a return on your investment sooner while minimizing the exposure to the risks commonly associated with
protracted construction schedules.
source: Modular Building Institute



Water Efficiency

L
EED rewards project stakeholders for ap- universal principles and practices that apply to
preciating where our water comes from, all construction.
how we use and recycle it while we have
it on site and where it goes once we are finished WE Credit 2 – Innovative Waste Water Technology
using it. The primary emphasis is on reducing rewards project stakeholders for utilizing fixtures
dependence on municipally supplied potable that out perform the allowable water quantities
water for irrigation, the transportation of waste listed in the Energy Conservation Act of 1992.
using potable water and overall water conser- This is done by conducting an inventory of those
vation. Through integrated design we can see fixtures associated with flushing or transporting
relationships between the Sustainable Sites Cat- waste. The fixtures are inventoried and bench
egory in LEED and the water conservation goals marked against those in the Act. Then, substi-
and intents of the Water Efficiency category. tutions are made to enact a water conservation
Rainwater harvesting can reduce the reliance on strategy that reduces the overall need for potable
conventional civil infrastructure while contribut- water associated with transporting waste. Points
ing to the need for irrigation, if there is one. Or,
are rewarded for achieving a 50% reduction or
the reductions on potable water demand due to more in potable water required to transport waste
more water efficient bathroom or restroom fix- below that allowed by the flow rates listed in the
tures can lessen the need for transporting waste Energy Conservation Act of 1992. This can be
while integrating well with an on site grey water achieved through a combination of water effi-
separation and treatment facility. cient fixtures and / or the utilization of rain water
or treated grey water for flushing. Estimates of
In LEED Version 3, 2009, the Water Efficiency water saved from a single waterless urinal range
Category carries a Prerequisite and ten possible from 20,000 to 60,000 gallons per year depend-
points. WE Prerequisite1Water Use Reduction ing on the location and frequency of use.
– 20% is based on the previous WE Credit One
- 20% Reduction based on the Energy Policy Act WE Credit 3.1 and WE 3.2 – Water Use Reduc-
of 1992. In the new version project teams must tion recognize the potential for conserving water
achieve a minimum 20% reduction in water use in any way possible with the exclusion of pota-
below that allowed in the Energy Policy Act of ble water used for irrigation which is accounted
1992 in order to meet WE Prerequisite 1 Water for in WE Credits 1.1 and 1.2. Modular build-
Use Reduction – 20%. In addition, LEED 2009 ing manufacturers and suppliers have embraced
awards two points to each credit in the Water many of the strategies commonly used to reduce
Efficiency category, doubling that available in water consumption. Water conservation and the
LEED Version 2.2, 2007. ability to implement these strategies in modular
construction is well known and largely a matter
As with the LEED Sustainable Sites Category, of choice. Current products are durable, reliable
the LEED Water Efficiency credits are not spe- attractive and reasonably priced.
cific to modular building. WE Credits 1.1 and
1.2 associated with reducing potable water de- WE Credit 3.3 – Process Use Water Reduction is
mand for irrigation are a matter of resource ef- specific to LEED for Schools. It is intended to
ficient landscaping and site water management reward any effort to aggregate a number of wa-
in any project. All construction whether con- ter conservation opportunities commonly found
ventional or modular can include the principles, in schools. If these uses are housed in modular
practices and products associated with water building units then they are in play just as they
conservation and site water management. Rain would be for any other building type.
water harvesting systems can be integrated into
modular building designs. Ecologically sensi- Water conservation and the LEED Water Effi-
tive landscaping, intelligent plant selection, in- ciency credits are gaining in priority and applica-
tegrated pest management and sensitivity to the tion as the awareness of the importance of water
microclimates buildings create when sited are and, in some cases, growing shortages emerge.



Water conservation is one of the hallmarks of Contest Aims to Green Senior Living
high performance green buildings and one area Modular Building Institute Extends Annual Award Contest for a
where modular building can enjoy the same Real-World Application
benefits as conventional construction. Several
modular construction manufacturers currently
list water conservation and LEED Water Effi- In 2008 MBI’s Awards of Distinction contest proposed a real-world
ciency credit compliance as part of their mar- scenario aimed at delivering a sustainable design to deserving
keting effort. At the same time modular build- community populations.
ing advocates need to be aware of the integrated
design implications for whole building and total
site water management to insure the completed Students from eligible schools of design, architecture and
design meshes site water harvesting opportuni- engineering submitted their plans for a community center of a
ties with current water conservation and water senior population called The Meadows, located in Crozet, Va. The
management strategies. The modular building
Meadows provides low-income housing to people ages 62 and
industry can benefit by studying the art and sci-
ence of stormwater management to better par- older.
ticipate in LEED discussions centering on how
a building should be sited, how retention ponds, The winning entry, pictured here, was submitted by Ball State
rain gardens and other site amenities contribute
architecture student Tyler Stanley. Stanley’s 4,900-sf design
to LEED credits with open space requirements.
Modular construction that anticipates inclusion capitalizes on some of the greenest aspects of modular
in projects with rain water harvesting is best if construction: use of recycled materials and reduced waste from
it has anticipated the detailing, structural loads off-site construction.
and system interfaces that are part of the build-
ing and site engineering necessary to be part of
the overall systems integration.

MBI’s student design competition offered a challenge to architecture students for a real-world
scenario. The winning entry (pictured here) came from Tyler Stanley of Ball State University. The
senior community center’s green features include: Low to no emitting materials; no VOC paint and
carpets; double-pane, low E windows; sound absorbing gypsum for reduce noise pollution; LED
lighting and low-energy appliances; and, a vegetative roof.



Energy and Atmosphere

C
urrent literature supports the fact that extent possible that a building will perform and
energy conservation and the attendant be operated and maintained as it was intended.
reduction in building operating costs are LEED requires fundamental commissioning of
two of the major drivers in the high performance the HVAC and controls, lighting and controls,
green building movement. LEED recognizes the domestic hot water systems and renewable en-
history of the energy conservation movement as ergy systems if they are included. Commission-
the energy crises of the 1970s and the tools that ing differs from traditional testing and balancing
have been developed to model energy use reduc- or the start up primary space conditioning equip-
tion via building envelope and building energy ment by manufacturer suppliers or subcontrac-
systems optimization since that time. LEED tors in that commissioning must insure that all
also recognizes the ongoing connection between systems are working collectively as intended. In
the production of primary power via fossil fuels the case of modular building commissioning is
and the consequences for air pollution, global assumed to be applied to a finished project.
warming and ozone protection. Increasing en-
ergy costs and growing concern about energy If a modular building is fully assembled prior to
availability and security are sure to keep the in- delivery and the systems that must be commis-
terest in energy conservation and renewable or sioned are installed and operational most funda-
alternative energy sources in the forefront of the mental commissioning activities can take place
high performance green building movement. in the factory. However, the modular building
is subject to additional commissioning activi-
All of the Energy and Atmosphere Prerequisite ties if connecting to the civil infrastructure, site
and Credit opportunities can be applied directly mounted renewable energy systems, site water
to modular construction projects. While this is supply pressure testing, etc. These activities can
true of conventional construction modular build- only happen in the field and are required for a
ing has a number of potential advantages if the complete commissioning report.
industry chooses to pursue them. Modular con-
struction that uses structural insulated panels or It should be noted that beyond the traditional
SIPS can produce relatively high R-values and commissioning activities themselves LEED re-
low infiltration rates if fabricated and construct- quires the following:
ed with good quality control. Steel and alumi-
num stud frame construction can also produce 1. Designate an individual as the commissioning
energy efficient units if care is taken to insure agent to lead, review and oversee the comple-
proper installation techniques and air sealing. tion of the commissioning process activities.
High performance windows contribute to the a. The commissioning authority shall have
pursuit of high performance building envelopes documented commissioning authority ex-
in each case as do proper air sealing procedures perience in at least two projects of similar
and quality entrance systems. Several modular scale, scope and complexity.
building manufactures tout superior energy con- b. The individual serving as the Commission-
servation and reduced operating costs as a func- ing authority shall be independent of the
tion of quality control in factory environments project’s design and construction manage-
as opposed to conventional construction where ment, though they may be employees of the
both labor and materials can be subject to the firms providing those services. The com-
influence of weather. missioning authority may be a qualified em-
ployee or consultant of the Owner.
The following discourse summarizes the rela- c. The commissioning agent shall report the re-
tionship of modular building and the LEED En- sults, findings and recommendations directly
ergy and Atmosphere Prerequisites and Credits. to the owner.
d. For projects smaller than 50,000 square feet,
EA Prerequisite 1 – Fundamental Commission- the commissioning agent may include quali-
ing of the Building Energy Systems fied persons on the design or construction
teams who have the required experience.
Commissioning is the art and science of using 2. The Owner shall document the Owner’s Proj-
diagnostic tools, experience and building fo- ect Requirements (OPR). The design team
rensic knowledge to guarantee to the greatest shall develop the Basis of Design (BOD). The
10


commissioning authority shall review these It is quite common for municipalities to base
documents for clarity and completeness. The their building code requirements on ASHRAE
Owner and design team shall be responsible standards and references. In this case the modu-
for updates to their respective documents. lar buildings in question are assumed to be per-
3. Develop and incorporate commissioning re- manently installed on foundations not meant to
quirements into the construction documents. facilitate removal or frequent relocation.
4. Develop and implement a commissioning
plan. EA Prerequisite 3 – Fundamental Refrigerant
5. Verify the installation and performance of the Management
systems to be commissioned.
6. Complete a summary commissioning report. This prerequisite prohibits the use of CFC
– based refrigerants in new building HVACR
Lastly it may be possible that the completed systems. These refrigerants are not permitted in
modular unit which has been commissioned new construction in the US but may be present
largely in the factory is still a subassembly in in central plants that modular buildings are ser-
a larger completed project. In this case all of viced by. If this is the case the project using the
the modular building commissioning activities modular building serviced by the central plant
will be part of a more comprehensive commis- must obtain an inspection of the central plant as
sioning plan and will have to be coordinated well as a commitment to phase out the equipment
accordingly. One of the most important roles a using CFCs in the central plant over time. Each
commissioning authority has when a project in- is weighed on its merits.
volves modular buildings is to act as the liaison
between the modular building manufacturing EA Credit 1 – Optimum Energy Performance
plant and the construction site. The commis-
sioning plan should address how commissioning This credit is based on meeting all the require-
activities that vary in scope and location will be ments of EA Prerequisite 2 Minimum En-
coordinated and reported. ergy Performance which mandates exceeding
ASHRAE 90.1 2007 minimum energy perfor-
EA Prerequisite 2 – Minimum Energy Perfor- mance requirements by 10% for new construc-
mance tion. In Version 3, 2009, LEED provides an op-
portunity to obtain up to twenty one points for
In LEED 2009, all LEED projects are subject new construction by computer modeling the pro-
to exceeding the minimum energy performance posed design against a base case building using
criteria set forth in Sections 5.4, 6.4, 7.4, 8.4, Appendix G of ASHRAE / IESNA 90.1 – 2007.
9.4, and 10.4 of ASHRAE / IESNA 90.1 – 2007 Once the base case is created and an annual op-
without amendments as well as the prescriptive erating budget is established the design team is
requirements of Sections 5.5, 6.5, 7.5 and 9.5 tasked with creating a design case building that
without amendments by 10% for new construc- reduces the annual operating budget by at least
tion and 5% for major renovations. The reader 12% below that required for the base case build-
is referred to ASHRAE / IESNA 90.1 2007 for a ing before points can be scored. Projects whose
complete description of the requirements. Gen- yearly operating budget for energy is 12% below
erally the building categories are: the Base Building modeling as established by
Section 5 – Building envelope Appendix G of ASHRAE 90.1 2007 can score
Section 6 – Heating, Ventilating and Air Con- the minimum two points. Projects with yearly
ditioning (including parking garage ventilation, energy operating budgets forty eight percent or
freeze protection, exhaust air recovery and con- more below the Base Building estimate are eli-
denser heat recovery) gible for nineteen points.
Section 7 – Service water heating
Section 8 – Power (including all building power It is important to note that the modular building
distribution systems) in question must be modeled in the context of
Section 9 – Lighting (including exit signs, build- the site and the final design. This exercise can-
ing exterior. Grounds and parking garages) not be done remotely or theoretically in the fac-
Section 10 – Other Equipment (including all tory. This is because energy performance and the
permanently wired electric motors) criteria that LEED requires to be considered are
11


dependent in whole or in part on final building ing projects. Integrated design is driving design
orientation, passive solar and natural ventilation trends that install relatively small-scale PV pan-
contributions, site lighting, occupancy and mi- els as window shading devices. Other eligible
croclimate conditions that effect yearly energy systems such as low impact hydro dams, while
use. contributing to the credit, are clearly a matter of
site selection and proximity. The contribution of
In large projects energy modeling using DOE.2e these systems to the reduction of the annual en-
or other sophisticated modeling software is used. ergy costs are reflected in the energy modeling
In smaller projects more prescriptive measures or prescriptive approaches to energy cost calcula-
can be used based on several ASHRAE publica- tions found in EA Credit 1. EA Credit 2 Renew-
tions such as the Advanced Buildings Core Per- able Energy points are rewarded for displacing
formance Guide. The LEED Reference Guide conventional fuels and the attendant reduction in
contains an extensive discussion of what evalu- yearly energy costs on a graduated scale. The
ation procedures are most appropriate and what percentage listed in the title of the credits refers
is acceptable as building envelope, building sys- to the reduction in dollars below the yearly en-
tems, site and occupancy variables. ergy cost in dollars for the base building modeled
in Appendix G or through some other prescrip-
EA Credit 2 – On-Site Renewable Energy Sys- tive method. They are:
tems 1% Renewable Energy 1 Point
5% Renewable Energy 3 Points
Once the yearly operating budget of the design 9% Renewable Energy 5 Points
case building has been determined using the 13% Renewable Energy 7 Points
procedures contained in EA Credit 1 the proj-
ect team can address meeting the annual energy EA Credit 3 – Enhanced Commissioning
demands of the project with renewable energy
sources and building systems. LEED considers LEED 2009 awards two points for EA Credit 3.
the following systems eligible for consideration Enhanced commissioning is related to the basic
in this credit: commissioning required for all LEED projects in
EA Perquisite 1. In addition to the basic require-
Photovoltaic systems ments inherent in EA Prerequisite I the commis-
Solar thermal Systems sioning authority must also:
Bio-fuel based electrical systems
Geothermal heating systems (Geothermal 1. Conduct a minimum of one commissioning de-
heat pumps are excluded but their benefits sign review of the Owners Program Require-
are considered in EA Credit 1 – Optimum ments (OPR), the Basis of Design (BOD),
Energy Performance) and design documents prior to the mid-docu-
ments production phase. A back check of the
Geothermal electrical systems
remarks and responses to the design reviews
Low impact hydro electric power systems
must be included in subsequent phases.
Wave and tidal systems
2. The Commissioning authority shall also re-
For EA Credit 2 these systems are generally con- view contractor submittals concurrent with
sidered to be located on site and dedicated to the the A/E reviews. Findings must go directly to
subject project. Systems such as photovoltaics the owner.
and solar domestic water heating systems can 3. Develop a systems manual that provides fu-
have their internal components installed in the ture operating staff the information needed to
modular building factory but final assembly of understand and properly operate the commis-
the collectors or PV arrays is typically done in sioned systems.
the field. This is certainly true of any array that 4. Verify the requirements for staff training and
is site mounted or part of a larger central array operating personnel have been completed.
dedicated to more than one modular building. 5. Participate in a review of the building opera-
tion within 10 months of substantial comple-
Renewable energy systems can be applied to tion.
any building construction type and are being As in the EA Prerequisite 1 – Fundamental Build-
found increasing frequently in modular building Systems Commissioning enhanced commis-
12


sioning activities and responsibilities may be is to acquire sufficient building systems data to
split between the manufacturing plant and the verify the building is performing as anticipated.
construction site. The commissioning plan must In this regard this credit is often evaluated as a
reflect how commissioning activities will be co- compliment to the commissioning activities that
ordinated. And, systems that are assembled or are taking place in the same time period, espe-
sub-assembled at the factory which become part cially if Enhanced Commissioning activities are
of the permanent installation must be commis- taking place.
sioned as part of the finished installation.
The work associated with obtaining this cred-
EA Credit 4 – Enhanced Refrigerant Manage- it can be relatively simple if the structures are
ment modest in scale and the systems are limited and
straight forward. Many modular building appli-
LEED 2009 awards two points for EA Credit 4. cations be they classrooms or small office are in
LEED rewards project teams that make respon- this category. Modular buildings of this type are
sible choices regarding the selection, installation often single zone structures with dedicated space
and maintenance of refrigerants. This credit conditioning systems and simple controls.
opportunity is not specific to modular building
but is a function of space conditioning equip- EA Credit 6 – Green Power
ment and the refrigerant choices that accompany
them. The point for this credit is obtained by not LEED 2009 awards two points for EA Credit 6.
using refrigerants or by selecting one that has the Green Power refers to electrical energy generat-
qualities and attributes of being efficient while ed off site using criteria established by the Center
minimizing the potential for ozone depletion and for Resource Solutions (CRS) Green-e products
global warming should the refrigerant wear out certification requirements. Projects are rewarded
prematurely, require difficult or dangerous main- one LEED point for contracting for at least 35%
tenance or escape to the atmosphere. R410A or of the project’s electrical requirements for two
Puron is preferable to R12 or R22. A LEED years. A second point is available if the contract
point is rewarded for selecting a refrigerant that doubles to 70% for the same two year period.
balances these criteria and still meets equipment
performance and warranty requirements. This credit is not specific to modular buildings
sans for the indirect implication that very energy
EA Credit 5 – Measurement and Verification efficient modular buildings can reduce the actual
kW required per year, hence lowering the per-
LEED 2009 awards three points for EA Credit centage of Green Power that is contracted for.
5. Measurement and Verification is a process by
which the operation and associated energy per- The literature supports the fact that modular
formance of a completed project is monitored for buildings can be very energy and resource ef-
at least one year using the processes and prac- ficient. Competitions now showcase the vari-
tices set forth in the International Performance ous ways in which modular building suppliers
and Measurement Verification Protocol (IP- are incorporating energy and water conserving
MVP) Volume III. The IPMVP allows the use equipment and features in completed projects.
of two protocols, Option B and D respectively Stakeholders representing modular buildings in
depending on the complexity of the project and LEED applications need to have an appreciation
the number of systems that use energy. for which activities are joined in the manufactur-
ing facility and which are a function of outside
While this credit is not specific to modular build- collaborations and team member participation.
ing project teams need to understand the require- It must also be noted that unless the modular unit
ment of the credit as it related to the installed represents the entire finished project, modular
controls, sensors, data acquisition systems and sub assemblies and modular units that comprise
other performance indicators the IPMVP proto- a portion of a larger whole project are evaluated
cols involve. Obtaining this point may require against the energy performance of the project as
coordination between the modular building sup- a whole.
plier and the HVAC and / or the mechanical,
electrical and plumbing engineers. The intention
13


Materials and Resources

M
odular building by nature is material In order to facilitate the LEED application the
and resource efficient. One of the great modular component or modular unit manufac-
economies of modular building is the ture must be intimately familiar with the nature,
ability to assemble repetitive units in controlled source and manufacturing processes associated
conditions. Another is to minimize material with the materials assembled in the modular
waste associated with conventional construction building entity in question. This will be discussed
due to weather intrusion and construction site further in the Credit interpretations below. The
theft. Modular components and subassemblies reader is invited to study the LEED Reference
that exhibit controlled tolerances can be coordi- Guide for the LEED rating system being used for
nated into larger projects. Whole modular units a more complete discourse on the subjects of ma-
—largely finished prior to arriving at the con- terials and resources.
struction site—can significantly limit construc-
tion waste generated at the site and contribute The Prerequisite and LEED Credit opportunities
directly to construction site waste management. in the Materials and Resources section are:

LEED rewards projects for recognizing where MR Prerequisite 1 – Storage and Collection of
materials come from, how they are used on site, Recyclables
whether or not they are salvaged during renova-
tions, and how the residual waste stream is man- This prerequisite is common to all LEED projects
aged. Special recognition is given to using ex- and not specific to modular building. The project
isting buildings, materials with recycled content team must illustrate how glass, aluminum, paper,
and those that are mined, harvested, extracted corrugated cardboard, and plastic are collected,
and assembled within 500 miles of the construc- stored and then removed from the project site
tion site. Finally LEED rewards projects that whether or not a municipal waste collection pro-
use products grown using good stewardship gram is in place. This is typically the responsibil-
practice, and are lightly processed or have low ity of the design team.
embodied energy.
MR Credit 1.1 – Building Reuse, Maintain
In order to accurately evaluate the role of materi- 75% of Existing Walls Floors and Roof
als and resources in modular building and LEED MR Credit 1.2 – Building Reuse, Maintain
projects the following must be understood: 95% of Existing Walls Floors and Roof
MR Credit 1.3 – Building Reuse, Maintain
There are no LEED certified products 50% of Interior Non Structural Elements
A product can not give a LEED project
points These credits only apply to LEED projects that
A product can contribute toward or comply involve existing buildings. In LEED 2009 MR
with LEED credit requirements Credit 1.1 is awarded two points. It is possible
that the existing building in question is a modu-
In LEED products fall into two categories: Con- lar building. It is also possible that the project
tribution Credits and Compliance Credits. involves adding modular buildings or new con-
struction that contains modular components to an
Contribution Credits require a calculation to de- existing building. In each case an inventory of
termine what percentage of the project’s materi- the building(s) is conducted to calculate the per-
als meet the requirement set forth by the LEED centage of each involved. These credits stay in
rating system that the project team is applying play unless the new construction being added to
for certification. Compliance Credits require all the existing building (if any) exceeds the size of
related materials to meet a certain requirement the existing building by two hundred percent, at
set forth by the standard. All products related which point these credits drop out and the exist-
to the credit must all pass the standard. These ing building materials segue into MR Credits 2.1
credits are pass or fail. and 2.2, Construction Waste Management.

14


MR Credit 2.1 – Construction Waste Man- LEED rewards incorporating used building ma-
agement, Divert 50% from Disposal terials in new construction and major renovation.
MR Credit 2.2 - Construction Waste Man- To date this practice is very limited in the manu-
agement, Divert 75% from Disposal facture of new modular building components
or modular units. However, it is quite possible
One of the significant economies associated that modular building practices could be used in
with modular construction is the ability to man- LEED projects where other aspects of the overall
age construction waste. LEED rewards con- construction could feature these materials. The
struction waste management at the construction percentages listed refer to the percentage of Di-
site by being able to account for the materials, visions Two through Ten material costs of that
by weight or by volume, that are diverted from are represented by reused materials.
landfills. This includes all non-hazardous ma-
terials excluding cut and fill and organic mate- MR Credit 4.1 – Recycled Content, 10% (post
rial removed from the site. One direct benefit of consumer + ½ pre consumer)
reducing the overall waste stream is the simpli- MR Credit 4.2 – Recycled Content, 20% (post
fication of construction waste management at consumer + ½ pre consumer)
the site and the attendant reduction in dumpster
costs and hauling fees. Modern modular building construction uses a
full range of materials with high recycled con-
In the case of modular building overall construc- tent. These materials are recognized for there
tion waste generated at the site can be reduced relatively high strength to weight ratios, mois-
significantly. Moreover there may be Innovation ture resistance and cost effectiveness. LEED
Points available to LEED project teams that can recognizes the contribution of material manufac-
illustrate similar waste management practices tures that use both post consumer and pre con-
are in play at the modular building manufactur- sumer recycled content. Post consumer recycled
ing facilities. In order to apply for an Innovation content is that which is manufactured from such
Point the LEED team must be able to do a similar items as plastic bottles and cans which, once
“upstream” evaluation to determine the amount used, find their way back into the manufactur-
of construction waste material generated in the ing process. Pre consumer recycled content is
fabrication of modular buildings at the plant and that which transfers from one industry to another
the amount also diverted from landfills. without interfacing with consumers. Fly ash in
concrete or wheat straw substrate are two exam-
In order to calculate MR Credits 3.1 through ples. In order to participate in obtaining these
5.2 LEED requires project teams to calculate credits the modular building manufacturer must
the cost of building materials in Divisions Two be able to identify and quantify the nature and
through Ten less labor and transportation costs. percentage by weight of recycled content in the
This number then forms the denominator in materials used in modular construction. These
the calculations used to determine compliance include but are certainly not limited to materials
with the Credit requirements in each. Achiev- commonly found in the modular construction in-
ing these credits requires a working knowledge dustry: oriented strand board (OSB) and insula-
of the source of the materials, their composition tion plastics found in structural insulated panels
and the point of purchase. Modular building (SIPs) agriculturally based substrates, linoleum,
representatives should familiar themselves with aluminum, metal and glass window assemblies,
the full range of credit requirements detailed in medium and light gauge steel framing, carpet
the LEED Reference Guides. Only materials systems, floor tile, acoustic ceiling tile, cabine-
that are permanently installed qualify for inclu- try, interior drywall partitions, surface treatments
sion in MR Credits 3 through 7. and fabrics, doors, metal roofing, etc. Each must
be evaluated for recycled content and cost rela-
MR Credit 3.1 – Material Reuse, 5% tive to the overall cost of the modular component
MR Credit 3.1 – Material Reuse, 10% or unit less labor and transportation. Because
transportation costs associated with transporting
15


modular building units is documented separatelyshow that at least 2.5% of the cost of the mate-
from the product this information simply needs rials in Division Two through Ten in the entire
to be recorded an provided to the appropriate project is represented by materials that have these
LEED submission contact person. attributes. In order to qualify for this Credit and
the point available the modular building supplier
MR Credit 5.1 – Regional Materials, 10% Ex- must be able to identify and quantify which ma-
tracted, Processed and Manufactured Region- terials comply. These are then evaluated against
ally the total project cost of materials in those divi-
MR Credit 5.2 – Regional Materials, 20% Ex- sions and a determination is made.
tracted, Processed and Manufactured Region-
ally MR Credit 7 – Certified Wood

These Credits recognize the economic and en- Certified wood is that which comes from sources
vironmental benefits of building with materials certified by the Forest Stewardship Council’s
that are found in proximity to the construction Principles and Criteria. These include but are not
site. The percentages listed refer to the portion limited to structural framing, sub-flooring, wood
of the total material cost less labor and trans- doors and finishes. In order to qualify for this
portation of materials in Divisions Two through Credit and the point available 50% of the value of
Ten. In order to qualify for these points the point the wood based products in the completed proj-
of purchase of the modular building component ect that are permanently affixed must come from
or modular building unit must be within a 500 FSC certified sources. The modular building sup-
miles radius of the project site. The modular plier should be able to identify and quantify what
building manufacturer must then be able to iden- those products are and have proof of the chain of
tify what building products used in the construc- custody that accompanies FSC certification. If
tion of the component or modular building unit the FSC certified source is within 5oo miles of
were extracted, processed, manufactured and the construction site credit can be taken for MR
purchased within that same 500 mile radius. For Credit 5.1-Regional Materials.
homogenous materials this can be a relatively
easy assessment. For materials that are complex
or which derive a portion of their materials out-
side the 500 mile radius this can be an involved
calculation. The 1000 mile diameter that results
from the 500 mile radius is a significantly large
area and many LEED projects get one or both of
the points associated with these Credits. Most
modular building units are shipped from within
a 500 mile radius of the construction site so it be-
hooves the project team to attempt these Credits.
It should be noted that the 10% and 20% of the
value of the materials on the project are calcu-
lated against the total cost of materials including
site development.

MR Credit 6 – Rapidly Renewable Materials

Rapidly renewable materials and products are
those which are derived from raw materials that
come to market in a ten year cycle or less. These
are typically such materials as bamboo, Agrifi-
ber, linoleum, cork, wool and cotton. LEED
awards a point to LEED project teams that can
16


Markets Currently Served by Commercial Modular Construction

source: Modular Building Institute,
2007 Commercial Modular Construction Report

17


Indoor Environmental
Quality and Modular Building

N
ext to overall energy efficiency, effec- We have arrived at this juncture in time with the
tive daylighting and natural ventilation,full capability for industry-change toward provi-
superior indoor environmental quality sion of both environmentally conscious buildings
is one of the most desirable and important at- and eco-friendly building materials. The modular
tributes of high performance green buildings. building industry has control over both the ma-
Improved health and optimum building occu- terials and quality control features that provide
pant performance as a function of interior envi- superior building atmospheres. LEED is used
ronments that are allergy free and non toxic are to explore the relationship of energy efficiency,
now appreciated as one of the most important the influence of daylight and natural ventilation,
returns on the investment in high performance the use of allergy free, non toxic materials and
green buildings. Studies linking occupant health the psychology of space with respect of acous-
and satisfaction to natural light and clean inte- tics and views to provide highly desirable spaces
rior air have been in the medical literature for using a variety of assembly techniques, includ-
decades. More recent studies range from those ing modular building. This is evidenced by the
focusing on single issues such as absenteeism creative and inspirational responses produced by
and lost asthma days to the importance of good modular building manufactures who have par-
acoustics to broader concerns of human ecology, ticipated in green building challenges. They are
ergonomics and the ongoing impact of spending proof positive the modular building industry can
as much as 90% of our time indoors. continue to pioneer and respond to the evolution
of the green building movement. The following
The design and construction market’s response to is a discussion of modular building as it relates
our growing awareness of the impact of the built to the LEED Indoor Environmental Quality cat-
environment on our general well being and the egory.
financial benefits associated with environments
optimized for health and productivity has been EQ Prerequisite 1: Minimum IAQ Performance
very positive. It has precipitated a major shift
in industry response and product availability This prerequisite is based on ASHRAE 62.1-
within the green building movement. Where it 2007, Ventilation for Acceptable Indoor Air
may have been difficult ten years ago to find non Quality with separate consideration of paragraph
proprietary products that were allergy free and 5.1 for buildings that are naturally ventilated.
non toxic today they are commonplace and price ASHRAE 62 is commonly used as the founda-
competitive. Some are enhanced by the fact that tion of many codes but LEED requires adher-
they are manufactured with recycled materials ing to local code requirements if they are more
and often found within 500 miles of the project stringent. Generally ASHRAE 62 determines the
site. Improvements in HVAC system efficiency, amount of ventilation air required as well as stan-
dehumidifying capability and the use of energy dards for the quality of ventilation air and how it
system modeling to right size space condition- is best distributed. The Prerequisite apples to all
ing systems and controls has all contributed to building types classified as permanently installed
more cost effective ways of maintaining accept- buildings regardless of the fabrication or con-
able psychrometrics and comfort conditions. struction deliver method.
We have arrived at the point where product sup-
pliers aware of the health consequences of how EQ Prerequisite 2: Environmental Tobacco
materials impact interior air quality have joined Smoke (ETS) Control
forces with an enlightened design and engineer-
ing community who have the diagnostic tools The Prerequisite to eliminate or strictly control
necessary to optimize both natural and mechani- environmental tobacco smoke is applicable to
cal space conditioning systems. LEED has pro- all building types. The LEED reference guide
vided the forum through which the principles gives specific requirements for the design, con-
and practices of integrated design can be used to struction, commissioning and control of smoking
combine the best of both in the most cost effec- areas inside LEED certified buildings if they are
tive ways possible. to be included. Requirements vary between com-

18


mercial and multi-family residential buildings. must be maintained in spaces that are not defined
They are not specific to modular buildings. as high density.

EQ Prerequisite 3: Minimal Acoustical Perfor- Spaces that are naturally ventilated must have
mance (LEED for Schools only) CO2 sensors in each space located between three
and six feet above the floor.
LEED for Schools contains this prerequisite
which is intended to provide minimum acoustic Modular building manufactures must confirm
performance in core learning spaces in academic these rates are achievable and install the proper
buildings. Attaining the credit is based on de- sensors and associated limit indicators to inform
signing classrooms and other learning spaces building operators and occupants when design
to meet the Reverberation Time (RT) require- conditions are not being met. If space condition-
ments of ANSI standard S12.60-2002, Acousti- ing is accomplished with a combination of forced
cal Performance Criteria, Design Requirements air and other equipment the LEED team must ex-
and Guidelines for Schools. Also, classrooms plain how ventilation air will be controlled and
and other core learning spaces must meet Sound how the sensors will work in concert with other
Transmission Class (STC) requirements except controls.
for windows which must meet an STC rating of
at least 35. EQ Credit 2: Increased Ventilation

In addition a background noise level of 45 dBA LEED rewards project teams for providing a
must be met using the methodologies described minimum of thirty percent additional ventila-
in annexes B through D of ANSI Standard tion air to the regularly occupied areas of the
S12.60-2002. Or, classrooms and other core building. The benefit is additional fresh air and
learning spaces must achieve an RC (N) Mark II increased assurance that any residual pollutants
level of 37 with HVAC equipment and installa- will be removed with additional ventilation and,
tions as defined in the 2003 HVAC Applications hopefully, effective filtration. This credit can be
ASHRAE Handbook, Chapter 47. applied to modular construction the application
of which must be modeled in EA Credit 1: Opti-
Modular building units can be optimized to meet mum Energy Performance.
these criteria as they are seldom fabricated of
heavy masonry construction or massive materi- EQ Credit 3.1 Construction IAQ Management
als that reflect sound. SIP construction, metal Plan During Construction
studs with multiple layers of drywall mounted
on resilient clips, acoustic ceiling tiles and other Obtaining this Credit requires understanding
acoustic design techniques can all be applied. the Credit intent with respect to modular build-
The strategy for meeting this Prerequisite and ing manufacturing environments and conditions.
the associated EQ Credit 9: Enhanced Acousti- The criteria for maintaining acceptable IAQ dur-
cal Performance can be formed around materi- ing construction are based on the Sheet Metal and
als and construction techniques commonly used Air Conditioning Contractors National Associa-
in the modular building industry. The overall tion (SMACNA) IAQ Guidelines for Occupied
approach must be considered against the site Buildings Under Construction, 1995, Chapter 3.
context, whether or not the finished project is When applied to conventional construction proj-
multi-story and ambient noise conditions. ects the intent is to insure that work in place is
protected, the project site is generally clean and
EQ Credit 1: Outdoor Air Delivery Monitoring free of excessive water, materials are effectively
stored and kept dry and ductwork is kept clean,
This Credit is intended to insure occupant com- especially if the HVAC system is used during
fort by monitoring the amount of air mechani- construction.
cally delivered to spaces with a density of 25
people per 1000 square feet or less, keeping it In modular building manufacturing plants the
within 10% of designed air flow rates. 15% conditions are often ambient, reducing the need
19


for supplemental space conditioning during con- Once healthy building products and practices
struction. The assembly areas are not subject to are implemented the LEED team can subscribe
excessive moisture or extremes in temperature to one of two techniques to obtain the point for
and are generally controlled to provide accept- this credit.
able working conditions. If modular units are
assembled in whole or in part outside these con- The first is to flush out the building with a mini-
trolled conditions do not exist and the modular mum of 14,000 cubic feet of outside air per
building units are subject to the same criteria for square foot of building. The air must be intro-
this Credit as conventional construction. And, it duced maintaining at least 60ºF and 60% relative
is assumed that factory finished units are shipped humidity. Alternative approaches to this tech-
and installed in ways that also maintain the in- nique are allowable if the building is occupied.
tent of the credit which assumes the precautions The flush out is complete when the total amount
are observed until the project is completed. In of air necessary to satisfy the credit requirement
order to meet the intent of this credit the con- has been routed through the building.
ditions expected by meeting the SMACNA
standard should be evidenced in the completed The second alternative is to perform IAQ sam-
project. The narrative provided in the LEED pling and testing using testing protocols con-
template for this credit should explain how this sistent with the US Environmental Protection
is accomplished. Agency’s Compendium of Methods for the De-
termination of Air Pollutants in Indoor Air. In
EQ Credit 3.2 Construction IAQ Management this approach testing is conducted to specifically
Plan Before Occupancy detect the presence and concentrations of the
pollutants listed above. This approach is much
LEED rewards project teams that build with al- more scientific and useful than simply flushing
lergy free non toxic material and building prac- air through the structure although both are ac-
tices as defined in EQ Credits 4.1 through 4.6 ceptable.
described below. As an extra precaution EQ
Credit 3.2 Construction IAQ Management Plan In order to meet the intent of the credit either
Before Occupancy is available to insure that method should be conducted on site in what is the
any residual indoor air pollutants are removed. completed LEED project. Air sampling and mea-
This is done by either flushing out the complet- surement done inside the modular building man-
ed building or measuring the same using IAQ ufacturing facility can be adversely impacted by
testing procedures focused on the following: the manufacturing environment. Also, modular
units can pick up pollutants during transportation
Formaldehyde (HCHO) not to exceed 50 that could impact the testing and which should be
parts per billion removed or ventilated out before the intent of the
Particulates not to exceed 50 microns per cu- credit can be met. LEED only rewards accept-
bic meter able IAQ levels in the completed structure so the
Total Volatile Organic Compounds (TVOC) testing must be completed on site.
not to exceed 500 micrograms per cubic me-
ter EQ Credit 4: Low Emitting Materials
Carbon Monoxide (CO) at 9 parts per billion
and no greater than 2 parts per million above The modular building industry is scrutinized
outdoor levels more than site-build construction for its ability
4-phenylcyclohexane (4-PCH) not to exceed to provide usable habitats with acceptable indoor
6.5 micrograms per cubic meter air quality, despite the fact that this feature has
also been proven to be very possible in modu-
In order to insure superior air quality in any lar environments. The combination of growing
completed structure it is important to build with awareness of the consequences of poor indoor
allergy free non toxic materials and maintain air quality coupled with LEED and the growing
the same with ecologically acceptable cleaning high performance green building movement has
products. Modular building is no exception. made compliance with this collection of credits
20

Modular Construction & LEED

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