8/14/2019 Florida Engineering Society Article - Hidden Risks Of Green Buildings

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The great irony of building green in thesoutheast is that the very concepts thatare intended to enhance a buildingsperformance over its entire lifetimeare many of the same concepts thatmake a building highly susceptibleto catastrophic moisture and mold

problems during its first few yearsof operation.

While green buildings (also sometimescalled sustainable design) have manypositive benefits, there is also strongevidence to suggest a direct correlationbetween new products/innovativedesign and building failuresespeciallyin hot, humid climates. Simply put,departing from the tried and trueoften means increasing the risk ofbuilding failure.

Two strong characteristics of mostgreen buildings are: 1) the use ofinnovative, locally-produced productsand 2) the implementation of newdesign and construction approachesthat are intended to reduce energyusage and be environmentally sound.

These environmental goals are typicallyorganized around a set of nationallyaccepted benchmark guidelines such asthose of LEED (Leadership in Energyand Environmental Design), which is

the standard established by the U.S.Green Building Council (USGBC).LEED certification is a checklist andpoint system of recommended practiceswhere achieving various point levels cancertify the building as having achievedsilver, gold, or platinum status. These

practices involve such issues as efficientwater and energy use, the reuse of wastematerials, and the use of renewable andregionally produced products.1

The overall goal of these new materialsand procedures is to achieve a structurewith reduced negative environmentalimpact both during constructionand throughout the buildings life.The intent of building green isunquestionably noble and good,and should be aggressively pursuedfor the improvement of the Earthsenvironment. However, because of thedramatic change that this will presentto the design and construction industry,its implementation will present newrisks that are likely to be both technicaland legal in nature.

Some of the legal risks are fairlyobvious, such as the risk of not meetinga building owners expectation ofachieving a certain level of LEEDcertification (i.e., implied or evenwritten warranties). Other risks are

more obscure, such as: The failure of new products to meet

their promoted performance levels,which is more likely withnew materials.

Accepting the higher standardof care that a green building

might presentwhat is currentlyconsidered best practices may nowbecome the new expected standardof care.

Failing to recognize (or prepare for)the unknowns in cost and scheduleimpacts that a green buildingmight present.

It is even unclear if a LEED certifiedbuilding can be built under a design-build method of construction withoutthe construction team assuming hugeamounts of unknown risks becauseof the vague definition of what isconsidered green.

The building industry has beenhistorically conservative, relying ontime-proven construction materialsand methods. The introduction of newmaterials and methods has not alwaysproven to be successful and sometimeshas resulted in notable building failures,especially those related to moistureintrusion and mold contamination.

The Hidden Risks of Green Buildings:

Why Moisture and Mold Problems are Likely

By J. David Odom, ASHRAE, Richard Scott, AIA, NCARB, LEED, APand George H. DuBose, CGC, Liberty Building Forensics Group, LLC

8/14/2019 Florida Engineering Society Article - Hidden Risks Of Green Buildings

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The proliferation of new products andinnovative building approaches relatedto green development is challenging thedesign and construction communityin such a dramatic fashion. Thesechanges virtually guarantee an increasein building failures and lawsuits. Pastexperience indicates that many of thesefailures will be predictable and some arelikely to be catastrophic.2

Examples of Technical Risks forContractors & Designers

Moisture intrusion, whether bulkwater intrusion through the buildingenvelope or relative humidity increasedue to the heating, ventilating, and air-conditioning (HVAC) system, resultsin a large percentage of constructionliability claims in the U.S. Moistureintrusion not only results in buildingdeterioration, but has been linked tooccupant comfort and health issues,especially in those buildings thatbecome contaminated with mold.3Sustainable building practices, someof which are part of the LEEDaccreditation process, can increase thepotential for moisture intrusion if notcarefully considered and implemented.Examples include: Vegetative roofs which obviously

are more risky than conventionalroofs (due to the constantly wetconditions) and must be carefullydesigned, constructed, andmonitored after construction.

Improved energy performance

through increased insulation andthe use of new materials whichmay change the dew point locationin walls, resulting in damagingcondensation and a reduced dryingpotential for wall assemblies.

Reuse of existing buildings orrecycled components which may notprovide optimum water-sheddingperformance in new configurationsor may not be readily integrated tothe adjacent new materials.

Use of new green construction

materials that have not been field-tested over time. Increased ventilation to meet indoor

air quality (IAQ) goals that mayunintentionally result in increasedinterior humidity levels in hot,humid climates.

Building startup procedures, suchas building flush out, whichcould result in increased moistureintrusion and mold growth.

New green construction materialsappear to be entering the market atan accelerated rate as manufacturersrealize the benefits of green products.Because many of these products helpto achieve multiple LEED credits,designers working on green buildingsare eager to specify these products. Therisk to contractors is that many of thesenew products are not time-tested, anddesigners often do not have the timeto fully research the efficacy of theseproducts. If the new product fails, itmay be considered a design error, butit may be difficult to determine if itis a design error, an installation error,or a product defect. Additionally,general contractors must rely on sub-contractors to install new materials whothey may not have experience with thenew material for proper installation.

Some of the expandable foaminsulation products are examples of

new green materials that pose risks.The water absorption properties ofthese insulation materials can be quitedifferent than what designers expectas compared to traditional fiberglassinsulation. Increased absorptionof water into the insulation couldnegatively affect the wall performance.This is not to say that such materialsshould not be used; however, theirproperties need to be recognizedand accommodated in the design.

The amount of ventilation (outdoor

air) necessary for occupant health andcomfort has been debated for decades.Although there are sound arguments onboth sides of the debate, the emphasison increasing ventilation to achieveLEED environmental quality creditshas increased the incentive to add moreoutdoor air to a building through itsHVAC system (a minimum of 30%more outside air is recommendedby LEED).1

This action is especially risky in theSoutheast U.S., where outdoor relativehumidity levels are elevated for a goodpart of the year. Experience in theSoutheast, as well as other areas of thecountry with humid summers, hasshown a direct correlation betweenthe number of moisture problems andincreased ventilation rates.

To effectively minimize the risk ofmoisture problems while increasingventilation, designers need toincrease the complexity and capacityof the HVAC components and

control systems to achieve properdehumidification. This adds tocontractor risk, since complex systemsfail more often than simple systems.Additionally, the complexity of thesystem operation can cause unintendedpressurization relationships where localdepressurization causes humid outdoorair to be drawn into interstitial buildingcavities, causing condensation andmold growth.4

Building owners, designers andcontractors all assume more risk whenthey deal with complex, and possiblyuntried, technologies. Pinpointingwhether the problem is design- orconstruction-related may be verydifficult after the problem hasalready occurred.5

Building startup procedures to meetLEED credits include a flush-out ofindoor containments using increasedoutdoor air either at the end ofconstruction or during the initialoccupancy period. The intent is toremove pollutants from off gassing ofvolatile organic compounds (VOCs)from new materials. The amountof air needed to meet the flush-outrequirements places a Southeast USbuilding at great risk because of theamount of moisture introduced withthe increased outdoor air. LEEDrequirements are that a minimum of14,000 cubic feet per square foot offloor area is required for flush out.

This presents multiple problems: mostHVAC systems are not designed todehumidify that amount of outdoorair which, in a 100,000 square footbuilding, is 1,400,000 cubic feet ofoutside air. Depending on outsideconditions at the time of the flush-outas much as 240,000 gallons of watercan be added to a 100,000 square footbuilding. This added moisture willget absorbed into building materials,finishes, and furnishings, increasing therisk of mold growth.6

Most specifications put the generalcontractor in charge of the flush-out,including controlling the relativehumidity levels during flush-out. If thesystem is not designed to handle theloads, the contractor is faced with adifficult challenge that may require theaddition of a temporary, and extremelycostly, dehumidification system.

Continued on Page 24

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BrowardRicardo G. Estripeaut, PE; FECONCreative Engineering GroupSponsor: Ramzi B. Asfour, PE

Ronald R. Eyma, PE; FPEGCity of MiramarSponsor: Rudy M. Ortiz, PE

Louis E. LeBrun, PE; FECONParkson Corporation

CalusaBrian J. Barnes, PE; FPEGCharlotte County Public WorksSponsor: Danielle Pitt Slaterpryce, PE

Michael Jankowski, PE; PEPPJohnson Engineering Inc.Sponsor: Christopher D. Beers, PE

Central FloridaJohn F. Becker, PE; PEPPHNTBSponsor: James P. Anglin, PE

MiamiArnaldo Carrillo, PE; PEPPT.Y. Lin InternationalSponsor: Francisco J. Alonso, PE

North CentralArthur L. Campbell, PE; PEPPCampbell Engineering of North

Florida Inc.

Tiffany Davies, EI; PEPPWilsonMiller Inc.Sponsor: David A. Kemper, PE

Northeast FloridaDow W. Peters III, PE; PEPPPeters and Yaffee Inc.Sponsor: Michael P. Whelan, PE

Stephen R. Weaver, PE; PEPPNodarse & Associates Inc.Sponsor: John B. Kimberly, PE

Northwest FloridaMatthew B. Hinote, EI; PEPPHatch Mott MacDonald Florida LLCSponsor: Steven White, PE

Brandon A. Knight, EI; FPEGEmerald Coast Utilities AuthoritySponsor: Michael N. Hamlin, PE

Kelly Perkins, PE; PEPPHatch Mott MacDonald Florida LLCSponsor: J. Brent Rawson, PE

PinellasJames Russell Tripp, PE; FPEIAdvanced Drainage SystemsSponsor: Charles Warrington, PE

RidgeJeffrey A. Beriswill, PE; PEPPDunkelberger Engineering & TestingInc.Sponsor: Craig Dunkelberger, PE

David James Molnar, PE; PEPPChastain-Skillman Inc.Sponsor: Stephen McConn, PE

Thomas R. Valentine, PE; PEPPSponsor: William R. Jonson, PE

Tampa

Joseph A. Cimino, PE; PEPPWater Resource AssociatesSponsor: Richard G. Smith, PE

M. Ali Iranmanesh, PE; PEPPAdvanced Engineering Group Inc.Sponsor: William J. Weber Jr., PE

Peter R. Lehmann, PE; PEPPUniversal Engineering SciencesSponsor: Mark Israel, PE

Quanghee Yi, PE; PEPPGolder AssociatesSponsor: Todd D. Anderson, PE

8/1/08 through 8/31/08

Conclusions

Theres one sure way to kill an idea:Sue it to death.

Quote from ENR,July 2008

What is the greatest risk to thegreen building movement? Its likelynot the increased costs associatedwith certifying that buildings aregreenits more likely green buildings

that dont perform to expectationsand, in some cases, may experiencesignificant failures. The increased costsof litigation and insurance that resultfrom underperforming green buildingswill be absorbed by designers (in ahighly competitive marketplace) butmost costs will be passed onto buildingowners. These increased costs, alongwith the negative publicity on failedgreen buildings, could dramaticallyinfluence building owners NOT tobuild green.

Only recently has the marketplacebegun to recognize the variouscontractual, legal, and technical risksthat are inherent to green buildings.A growing number of experts havesuggested that the first two stepsto improved green building riskmanagement are to: 1) recognize theunique risks for green buildings in hot,humid climates and 2) develop a setof guidelines that merge the uniquerequirements in hot, humid climateswith green building guidelines

In the Florida, our hot humid climateposes additional long-standing

recognized technical risks, whethera building is sustainable or not.However, many of the green buildingconcepts, such as those found inLEED requirements, exacerbate thosetechnical risks. USGBC recognizes theclimatic and regional technical gaps buthas not addressed them in the currentversions of LEED. These gaps may notbe easily recognized by designers andcontractors in their pursuit ofLEED credits.

The design and constructioncommunity must not assume thatif you build green then you will bebuilding regionally correct. Untilthe gaps between regionally correctbuildings and green buildings areaddressed the design community wouldbe advised to prioritize the lessonsalready learned from the waterproofing,humidity control, and buildingforensics community. Without these

priorities, poorly functioning greenbuildings are the likely result andthis could be the ultimate killer forthe green building movement in ourunique climate.

In our opinion the solution to goodperforming, green buildings in Floridaare at least three-fold: Development of a unique set of

Hot, Humid Climate DesignCriteria that integrates (andprioritizes) hot, humid climatecriteria with current green buildingpractices. Best practices for hot,humid climates must take priority

over green building practices. A detailed Green Building Risk

Management Plan that providesguidelines for the design andconstruction team from conceptthrough the 1-year warrantyperiod. These guidelines wouldincorporate the best ideas of greenbuilding specialists, moisture controlspecialists, attorneys, and insurance

companies. A hot, humid climate customized

Building Commissioning Programthat identifies, and resolves, theknown conflicts between nationalgreen building criteria and specificregional criteria. n

Liberty Building Forensics Group, LLC(www.libertybuilding.com ) is a firm that specializesin forensic building investigations and expert

witness/litigation support. Their staff has led thelitigation support of some of the largest buildingfailures in the country, including the $60 milliondefect claims at a luxury resort in Honolulu and the

$20 million Martin County Courthouse problems.They have performed green building-related serviceson over $3 billion in new construction since 1995.Their staff has authored three manuals and over 50technical publications. Liberty Building Forensics

Group

References1 U.S. Green Building Council. http://www.usgbc.org/.2 Odom, J. David; Scott, Richard; and DuBose, George H. The

Hidden Risks of Green Buildings: Avoiding Moisture and MoldProblems.Washington, DC: National Council of ArchitecturalRegistration Boards (NCARB), 2007.

3 U.S. Environmental Protection Agency/ Office of Air and Radiation/Indoor Environments Division.Mold Remediation in Schools andCommercial Buildings.Washington, DC:EPA, March 2001.

4 Odom, J. David and DuBose, George H.Mold and MoisturePrevention. Washington, DC: National Council of ArchitecturalRegistration Boards (NCARB), 2005.

5 LEED for New Construction. U.S. Green Building Council. www.usgbc.org/DisplayPage.aspx?CMSPageID=220.

6 Brand, Stewart. How Buildings Learn: What Happens After TheyreBuilt. New York: Viking, 1994.

Hidden Risks Continued From Page 13