The Wood User's Guide to Green Building - California Redwood ...

The Wood User’sGuide to Green Building

Table of ContentsIntroductionWood for a Cooler Planet 5Wood and Greenhouse GasesWhat is Greener than Wood? 9Green Building StandardsWhat are Green Building Standards? 17Materials Origin and ImpactHow Wood Rates 25ConclusionSustainability Reigns Supreme 33Front and inside covers: Green-built homes inCastle & Cooke’s Windermere community in Bakersfield,California offer energy efficient designs.3

4This spread and following page: Blakely Hall in Issaquah, Washington achieved a ratingof Two Globes from the Green Building Initiative in recognition of the incorporation ofenergy and environmental considerations in the building’s planning and construction.

IntroductionWood for aCooler Planet5

Introduction — Wood for a Cooler PlanetCalifornia is gagaover green buildings.The concept, not the color.Since the turn of the century, interest has explodedin creating more environmentally sound, energyefficient and water-saving structures. And thedesire to build green is growing exponentially.Some potential homebuyers are attracted togreen because it’s the right thing to do – andothers are attracted to the savings they get onheating and water bills, among other things.Much of the focus on building green today centerson commercial development and governmentbuildings. These structures consume considerableresources and many governments have seizedthe opportunity to position themselves asenvironmental leaders. Residential constructionappears to be the next frontier. Home builders areincreasingly featuring green attributes and greenlabels in marketing efforts.The United States Department of Energy says thatAmerica’s 81 million buildings6

Wood and Greenhouse GasesWhat is Greenerthan Wood?9

Wood and Greenhouse Gases — What is Greener than Wood?When you talk about construction materials,wood is about as green as it gets.Wood is renewable. Steel,plastics and concrete aren’t.Wood is recyclable andbiodegradable.That’s three reasons why nine outof 10 homes today are built withwood.While lumber and plywood areused predominantly in residentialconstruction, there is considerablepotential for expanding wood usein commercial buildings.The same considerations that makewood a green building materialfor homes make it a good choicefor non-residential construction.Low-rise buildings three storiesor less, in particular, are moreamenable to wood constructionnow that building codes increasinglyrecognize creative ways to encourageusing wood.See www.woodworks.org formore information on using woodin commercial construction.Using more wood in non-residential structures like schools, stores and office buildings could saveenergy and reduce greenhouse gas emissions.Photo courtesy of APA - The Engineered Wood Association.10

Managed forests remove carbon dioxide fromthe air. Wood stores the carbon, keeping it outof the atmosphere for the long haul.Removing Carbon from the AirWood, by its nature, helps reducegreenhouse gas emissions.The biggest contributors toglobal warming are three gases– carbon dioxide, methane andnitrous oxide.Trees remove CO2 from theatmosphere and replace it withoxygen. In fact, wood is about 50percent carbon by weight.Through photosynthesis, treesabsorb the carbon and store it intheir leaves, roots and wood fiber.Younger trees grab more CO2 thanmature trees. The older trees storecarbon dioxide well, but the rateat which they absorb carbon hasslowed significantly. Some oldgrowthforests may actually releasemore CO2 into the air than theyremove.California’s laws governing forestmanagement are centered onthe idea of sustainability – justas green building standards are– especially on privately-ownedtimberland.When trees are harvested on privateforestland in California and theatmospheric carbon they absorbedis safely secured in wood products,new seedlings typically arereplanted to replace them. Youngtrees remove carbon from the airfaster and more efficiently than themature trees they replaced, andforesters continue a perpetual cycleof removing and storing carbon.11

Wood and Greenhouse Gases — What is Greener than Wood?At the same time, the carbonabsorbed by the harvested treesgets stored for the long-termin lumber, furniture and otherproducts.According to the U.S.Environmental ProtectionAgency, it is estimated that eachyear, forests in the United Statesremove the greenhouse gasesemitted by 139 million cars.In addition to pulling carbonout of the air while they grow,managed forests also help reducethe amount of carbon releasedinto the atmosphere by controllingfuel loads. That lowers the threatof catastrophic wildfires that spewmillions of tons of greenhousegases into the air every year.Renewable, recyclable wood is a greenbuilding material excellent for residential andcommercial construction.Some consumers fear thatusing more wood will lead todeforestation. While tropicaldeforestation is a significantcontributor to greenhousegas emissions, deforestation isnot an issue in California orelsewhere in the United States.“The arguments to promote “local food” areno more or less valid when considering one’sconsumption of wood products. Forestryremoves carbon and conserves resources moreefficiently in California than in most cornersof the globe.”— Dr. Keith Gilless, University of California - Berkeley12

California grows far more woodthan it harvests every year andhas about the same amount offorestland as it did a hundredyears ago. The vast majority ofCalifornia’s wood is harvestedfrom private forestland, andtherefore in accordance withlong-term sustainability plansand regulations.But rather than harvest treesgrown right here at home,California imports about 80percent of the wood it uses fromplaces where Californians have nosay in environmental standards orregulations.Despite upholding some of the highestenvironmental standards in the world, Californiaimports nearly 80 percent of the wood it uses.Overcrowded forests are prone to burning in catastrophic wildfires. Managing forests can reducefuel loads and emissions from wildfires while safely storing carbon in wood.13

Wood and Greenhouse Gases — What is Greener than Wood?Global Focus on CO2CO2 gets so much of thegreenhouse gas story spotlightbecause it is closely linked toenergy, and because atmosphericcarbon levels are on the rise.When used in construction, woodretains its stored carbon. It stayssafely out of the atmosphere forthe life of the wood structure,and even then wood can often berecycled.Using wood keeps CO2 out of theatmosphere for a very long time.It’s not just wood framing thatis beneficial. All wood doors,cabinets, flooring, molding andfurniture store carbon dioxide.While wood represents 47 percentof all raw materials used in theUnited States, the energy usedto produce it is just 4 percentof the energy used to make allmanufactured materials. That’sbecause wood is energy-efficient.Not only is wood grown byharnessing solar power, butmore than 60 percent of woodprocessing is powered by biofuels,a far cleaner source of energythan fossil fuels.Energy to BurnBiofuel energy means burningwood and other organic materials– chips, agricultural waste,bark, sawdust – to producesteam. The steam drives aturbine, which turns a generatorto create electricity. BiofuelManaging forests can conserve criticalresources for generations.14

A Northern California biofuel plant turns wood chips and agricultural waste into clean energy.“One of the best ways to address climate change isto use more wood, not less. Every wood substitute– including steel, plastic and cement – requires farmore energy to produce than lumber.”— Dr. Patrick Moore, co-founder of Greenpeaceenergy results in relatively lowemissions, whereas burningfossil fuels results in significantcarbon emissions. The U.S.Environmental Protection Agencyconsiders biofuel emissions toBiofuels can help California meet its growingdemand for energy.be “impact-neutral” on globalwarming because burning barkand agricultural waste for energycreates no net emission increase.Although the production ofbiofuel energy has fallen inCalifornia since 1992, increasedrecognition of the importanceof thinning overgrown publicforestlands to reduce the threatof catastrophic wildfires mayhelp revive the industry and, inturn, reduce reliance on importedwood and environmentallyharmful fossil fuels.15

Wood and Greenhouse Gases — What is Greener than Wood?More Good News about EnergyThere’s more to wood’s energystory than the clean energy thatcan come from it.The energy to grow wood comesfrom the sun. Other materials likesteel and concrete require a greatdeal of energy to produce.Studies have shown that fromtheir creation to their scrapping,non-renewable products likeconcrete, steel and aluminumconsume up to 250 percent morefossil fuel energy than woodproducts. Using concrete andsteel therefore results in greatergreenhouse gas emissions thanusing wood.A 2005 study compared a woodframehouse to a steel-framehouse and a wood-frame houseto a concrete-frame house. Woodoutperformed steel and concreteacross a range of environmentalperformance criteria. Steel andconcrete required far more energyto create and caused more airpollution. Using steel generated26 percent more greenhousegas emissions than wood. Usingconcrete generated 31 percent more.Energy Efficiency Comparison — Wood to Steel and ConcreteMinneapolis HouseWoodFrameSteelFrameDifferenceSteelenvironmentalimpact vs. woodEmbodied energy (GJ) 651 764 113 +17%Global warming potential (CO2 kg) 37,047 46,826 9,779 +26%Air emission index (index scale) 8,566 9,729 1,163 +14%Water emission index (index scale) 17 70 53 +312%Solid waste (total kg) 13,766 13,641 -125 -0.9%Atlanta HouseWoodFrameConcreteFrameDifferenceConcreteenvironmentalimpact vs. woodEmbodied energy (GJ) 398 461 63 +16%Global warming potential (CO2 kg) 21,367 28,004 6,637 +31%Air emission index (index scale) 4,893 6,007 1,114 +23%Water emission index (index scale) 7 7 0 0%Solid waste (total kg) 7,442 11,269 3,827 +51%Source: Consortium for Research on Renewable Industrial Materials (CORRIM)16

Green Building StandardsWhat are GreenBuilding Standards?17

Green Building Standards — What are Green Building Standards?Green building standards are meant to be tools tohelp builders and architects design, construct andpromote environmentally sustainable structures— and for consumers to understand how theycan reduce their carbon footprint.These systems encompass siteplanning, structural design andmaterials analysis. They aimto promote construction andland use practices that conserveenvironmental resources andimprove energy efficiency.At the center of green buildingscience are four Rs:Reduce.Recycle.Reuse.Renew.Green building relies oncomplex science, innovationand common sense. Greenbuildings use less constructionmaterials because of betterplanning such as designingrooms in four foot multiples toaccommodate standard-sizedwallboard or plywood sheets.Green buildings use less energyand water by design.Previous page: Castle & Cooke’sWindermere community in Bakersfield,California embraces green building principles.Right: Wood is featured prominently insideBlakely Hall, Washington, which earneda rating of Two Globes from the GreenBuilding Initiative.18

In general, recycled products arefavored when feasible. Even thestructure itself can be designed to berecycle-friendly at the end of its life.Old construction materials arereused if structurally sound.Naturally generated energy, such aspassive solar design, is encouraged.Green building encompasses manythings, including selecting plantswith less pesticide and water needs,using low flush toilets and tighterheating and ventilation ducts; andkeeping more onsite constructionwaste out of landfills.At first, some builders avoidedbuilding green because of the cost itadded to construction. But as moregreen building products come tomarket, the prices keep falling.Estimates vary as to how muchgoing green might add to theinitial cost of construction. Greenbuilding supporters expect that thesavings on energy and water useoffset higher initial costs over thebuilding’s life.Are the Standards Standard?Evaluating green buildingprograms can be confusing becausethere are a lot of standards and/or guidelines being proposed by alot of organizations. Good news:there are more similarities thandifferences among them.There are the Minnesota DesignGuidelines, Built Green ColoradoThe U.S. Green Building Council’s Leadershipin Energy and Environmental Design, orLEED, is a leading-edge system for designing,constructing, operating and certifying greenbuildings. The Green Building Initiative’s GreenGlobes is an Internet-based alternative.and Wisconsin Greenbuilt.The National Association ofHome Builders has its own greenconstruction guidelines. TheCalifornia Building IndustryAssociation has a Green BuilderInitiative. There’s also a Californianon-profit called Build It Green,which has a set of guidelines.In 1993, the United States GreenBuilding Council created perhapsthe best-known rating system,LEED® – Leadership in Energyand Environmental Design.LEED has programs specificto new construction, existingbuildings, commercial interiors,homes, and more.Newer to the U.S., but also wellknown, is Green Globes, aWeb-based tool that includesan assessment protocol, ratingsystem and guide for integratingenvironmentally friendly design intocommercial buildings. It featuresmodules for “New Construction”and the “Continual Improvementof Existing Buildings” and facilitatesrecognition of completed projectsthrough third-party assessment.LEED is a registered trademark of the U.S. Green Building Council. Green Globes is a trademark of the Green Building Initiative.19

Green Building Standards — What are Green Building Standards?Buildings that complete anindependent, two-stage assessmentprocess receive a final rating ofone, two, three or four GreenGlobes, which are roughlyequivalent to the certified, silver,gold and platinum levels thatare offered under LEED. Infact, a report prepared for TheCarpenters Industrial Councilby the University of Minnesotaestimates that nearly 80 percent ofthe available points in the GreenGlobes systems are addressed inLEED 2.2 and that more than85 percent of the points specifiedin LEED 2.2 are addressed in theGreen Globes system.The California Integrated WasteManagement Board has a wealth ofinformation on green building withlinks to most of the standards orguidelines in use around the stateand throughout the country. See:www.ciwmb.ca.gov/GreenBuilding/Design/Guidelines.htmJust complying with the requirementsof California’s existingbuilding codes compares favorablywith most commercial greenbuilding programs and those ofother states. And California stillwants to be greener.California’s Building StandardsCommission is developing statewidegreen building standards that takea different approach from manyexisting standards.Rather than offering architectsand builders only an extensivelaundry list of voluntarygreen options as most existingguidelines do, the state is alsocreating a list of mandatoryrequirements, such as low-flushThe Gulf Islands Operations Centre designed by Larry McFarland Architects, Ltd is the firstbuilding in Canada to achieve a LEED Platinum rating.20

Reducing greenhouse gas emissions and California’s increasing demands for energy have helpedfuel an interest in green building.toilets and a 50 percent reductionin construction waste.California’s emerging greenstandards also encourage the useof wood by allowing buildersto use responsibly grown andharvested timber certified byany of four national marketinggroups. LEED and Build It Green,in contrast, reward only woodcertified by one group.California’s energy efficiencystandards are already muchtougher than those of the federalgovernment. In the wake ofone of its recent energy crises,California updated its energyefficiency rules in October 2005to call for more efficient lighting,the use of radiant barrier panelsand improved window glazing,among other things.More information on thosestandards can be found at theCalifornia Energy Commissionwebsite. www.energy.ca.gov/title24/2005standards/index.html21

Green Building Standards — What are Green Building Standards?California’s Higher StandardsCalifornia is developing evenstronger efficiency standards, andwill likely remain a world leaderin advancing green buildingpractices.The executive order signed byGovernor Schwarzenegger inDecember 2004 mandated that newand existing state office buildingssharply increase their energy andwater efficiency in keeping with theprinciples of green building.Some local governments haveadopted green building ordinancesor issued voluntary guidelines. SanDiego County has had voluntaryguidelines since 1997. SantaMonica’s energy efficiency andrun-off guidelines have also beenin place more than a decade. SanMateo County and San Franciscohave green requirements forgovernment buildings. MarinCounty demands that new homesbe more energy efficient. Andother cities and counties continueto follow suit.Like California, the federalGeneral Services Administrationrequires new U.S. governmentbuildings to increase energy andwater efficiency.Other groups, like the AmericanSociety for Testing and Materialsand the American Society ofHeating, Refrigerating andAir-Conditioning Engineers,are creating minimum highperformance standards.Materials and Resource Considerations within LEED and Green Globes.IssueLife CycleAssessment (LCA)RenewabilityForest CertificationLocally ProducedMaterialsOther PossiblePointsLEED ® for New ConstructionNot currently included; the USGBC isconsidering how to incorporate LCA intofuture LEED products1 point if 5% of the total value ofbuilding materials comes from rapidlyrenewable sources, defined as 10-yearrotation or less1 point if 50% or more of the woodbasedmaterial and products are FSCcertified1 point if minimum 10% of totalbuilding materials were extracted,processed and manufactured withina 500 mile radius; a second point for20% minimum1 point for low-emitting materialsif composite wood and agrifiberproducts contain no addedureaformaldehyde resinsGREEN GLOBES for NewConstruction10 points each for using LCA tools tochoose building systems or assemblies5 points for proportion of materialsthat are bio-based, such as greeninsulation, natural fibers and naturalstructural materials5 points for lumber and timber panelproducts that originate from sustainablesources and are certified through SFI,CSA, FSC or ATFSPotential advantages of locallymanufactured materials are captured inpreference for materials that haveundergone LCA5 points for environmentallypreferable products and equipment thatare third-party certified0.5 points for raised floors0.5 points for partition walls that areeasily removed and recyclable22Source: Wood Promotion Network

The goal for all these programs isto raise the efficiency bar to levelshigher than currently set in statelaw or regulations.How Do the Rating Systems Rate?How the rating systems ratedepends on who you talk to.First of all, it’s important tounderstand that with the exceptionof some state and local governmentprojects, there is no requirement“Many green building programs determineenvironmentally preferable products based onintuition, bias, and internal politics.”— Dr. Jim L. Bowyer, Professor Emeritus of Bioproducts andBioprocess Engineering, University of Minnesotathat a builder or designer must gettheir project rated for greenness.It’s also important to understandthat buildings can be built “green”without third-party certification.Rating entities charge moneyfor certification – sometimes somuch money that developersbelieve going through the processneedlessly inflates their bottomline.Instead, they go ahead andbuild green and leave it at that.Like so many other things, thebeauty of a rating system is oftenin the eye of the beholder. Somepeople say a particular ratingsystem demands too much ofarchitects and builders. Othersinsist it doesn’t demand enough.Different rating programs havedifferent costs. The University ofMinnesota found that certifyinga commercial building throughLEED could cost $20,000 for nonmembers($17,500 for members),plus a fixed registration fee of $600($450 for members), compared toa flat registration fee of $500 forGreen Globes with certificationcosts ranging between $4,000 and$6,000. The October 2007 editionof BUILDERnews says LEEDcertificationof a commercialstructure can cost in excess of$50,000.Rating systems also have differentpoints of emphasis. For instance,Green Globes emphasizes “EnergyUse” above all other categories.In contrast, LEED allocatescomparatively more points to“Materials.” Within its “Materials”category, LEED credits onlymaterials that are renewablewithin 10 years. It credits bambooas renewable but not wood.LEED also recognizes only onesustainable forestry certificationprogram and requires certificationfor wood only, not otherresources like bamboo, steel orconcrete.23

Green Building Standards — What are Green Building Standards?Green Globes is recognized asbeing user-friendly, practical andaffordable, while also helping toachieve the desired end result.The fact is that rating systems areevolving – and evolving quickly.A key change appears to be amovement away from ratingsystems that dictate what practicescan and cannot be used tosystems that reward performancein improving sustainability.Different rating systems are alsogeared toward different segmentsof the construction industry. Thefirst word in LEED, its supporterslike to say, is Leadership. SoLEED says its standards should behigher than other rating systems.In fact, LEED targets just the top25 percent of the market.Although similar to LEED in whatconstruction strategies it rewards,Green Globes is designed formore widespread appeal.Projecting Market DemandWhile green building is a popularidea, it’s still unknown howcommercial standard systemswill fare when the rubber meetsthe road. In other words, howmuch of an impact will theyreally have on sales? How muchmarket advantage will there beto getting an independent rating?How much will the consumer bewilling to pay?The argument goes that if anarchitect or builder demonstratesa home or some other structureis LEED certified or has a ratingof three Green Globes that’s akinto the “Good Housekeeping Sealof Approval” – an independentthird-party has vouched thatthe building was designed to beenergy and water efficient, that itused materials sustainably and hasother green characteristics.It’s too soon to know if buyerswill be content in the belief thata building is “green” because itcomplies to strict standards and isconstructed by a builder who didthe right thing – chose sustainablematerials, attained energy savings,etc. – or whether buyers willdemand and pay for a seal ofapproval.Nor do we know how far greenmandated programs will spread.While developed as voluntaryguidelines for certain types ofbuildings, local governmentsincreasingly are requiring designersor builders to certify projectsmuch in the same way the state ofCalifornia currently insists biddersfor state office building projects earnat least a LEED Silver rating.Click on LEED Credits atwww.BuildingGreen.com for moreinformation on specific credits or visitwww.thegbi.org or www.usgbc.org.24

Materials Origin and ImpactHow Wood Rates25

26Sustainable forest managementconserves a host of forest resourceslike wood, soil and water.

Materials Origin and Impact — How Wood RatesWood rates very well, if its prevalence as aconstruction material is any indicator. It rateswell when you apply science, too.Generally speaking, a relativelysmall amount of the points usedin green rating systems are basedon wood or other constructionmaterials. Far more points comefrom energy efficiencies andthe like.But if from this point forwardevery new home built in theUnited States that wouldnormally be framed in woodwere instead framed in steel, thedifference in energy consumptionwould be roughly equivalent tocontinuously operating a fleetof 950,000 SUVs, each driving20,000 miles each year.Using wood makes a difference.But green building rating systemsdo not treat wood equally. LEEDcredits only wood certified by theForest Stewardship Council.That represents less than onesixthof the certified forestsin North America. In notrecognizing other crediblecertification systems, LEED limitsthe supply of lumber that can beused in green building.Green Globes recognizes woodcertified not just by the ForestStewardship Council but alsoby the Sustainable ForestryInitiative, the Canadian StandardsAssociation and the AmericanTree Farm System – which are allvalid certification systems aimedat promoting sustainable forestry.Being rewarded for using woodapproved by a broader range ofcertifying agencies gives buildersmore choice and encouragessustainable forestry on a broaderscale – an approach California issupporting in the standards it isdeveloping.If from this point forward every new homebuilt in the United States that would normallybe framed in wood were instead framed insteel, the difference in energy consumptionwould be roughly equivalent to continuouslyoperating a fleet of 950,000 SUVs, each driving20,000 miles each year.27

Materials Origin and Impact — How Wood Rates390 Million Acres of Certified Forest in North AmericaCertification:American Tree Farm SystemThe Forest Stewardship CouncilSustainable Forestry InitiativeCanadian Standards AssociationOf the more than 390 million acresof certified forest in North America,the Canadian Standards Associationcertifies nearly 180 million acres.The Sustainable Forestry Initiativecovers 132 million acres. The ForestStewardship Council certifies 57million and the American TreeFarm System 24 million.The websites for the ForestStewardship Council and theSustainable Forestry Initiativeboth detail their requirements forcertification. See www.fscus.organd www.sfiprogram.org.Generally, third-party certificationis awarded to private timberowners who employ the bestpractices of sustainability. Thereare requirements relating to thelicensing and training of forestmanagers, rules on harvestingpractices, protections for soil, airand water quality, and more.Interestingly, a 2003 study byCalifornia Polytechnic Universityin San Luis Obispo found thatthe rules California imposeson forestland owners are, inmost cases, as strict or stricterthan those set by the Forest807060504030201001st Qtr10%8%6%4%2%0%The O Bel Sole! development by Jennie Stabile & Al Stabile/K Street East LLC in Lancaster,California features 41 green homes.28

Advanced science and technology have become key tools of sustainable forestry.Stewardship Council and theSustainable Forestry Initiative.For an overview of the comparison,visit: www.calforests.org/pdf/CalPoly_Explainer_Bro.pdf. Forthe complete text of the study see:www.ufei.calpoly.edu/files/ufeipubs/CAFPC.pdf. The study is the firstitem after clicking on the A-Zdirectory.Sustainable ForestryLeadershipCalifornia is recognized as a worldleader in sustainable forestry.Before a tree can be turned intolumber in California there has to bea comprehensive harvesting plandeveloped by a licensed RegisteredProfessional Forester and approvedby state regulators with input frombiologists, geologists, hydrologists,archeologists and fish and wildlifespecialists, among others.Every harvest and replantingoperation on private forestlands inCalifornia includes provisions toconserve resources and maintainhabitat for diverse wildlife. Evenaesthetics must be considered,and all private forest managementplans are open to public review.California’s tough forestry rulesare one reason some builders –going for green certification ornot – prefer to use Californiagrownwood.29

Materials Origin and Impact — How Wood RatesLife Cycle Assessment EmergesAnother important distinctionbetween LEED and Green Globesis that Green Globes uses adifferent methodology than LEEDto calculate the ecological merits ofconstruction materials.This difference has a directimpact on how constructionprojects can earn points. As anexample of how standards canbe employed, LEED’s ratingsystem grants a builder onepoint if at least 50 percent ofthe wood-based materials andproducts used are certified bythe stewardship council. Anotherpoint is earned if 10 percent oftotal construction materials areprocessed or manufactured within500 miles of the building site. Anadditional point is awarded if 20percent of the materials are fromlocal sources.While Green Globes doesn’treward materials manufacturednear a construction site, itdoes reward design teams thatincorporate Life Cycle Assessmentas part of the decision-makingprocess – and LCA takes intoaccount the environmental impactof transporting the material.LCA does just what the namesays: it examines the impact of amaterial, assembly or even wholestructure, from its creation to itsdisposal. It is the most rigorousscientific methodology that canbe applied to the selection ofmaterials or assemblies.For example, an assessment of abuilding material (like wood, steelor concrete) calculates a range ofenvironmental impact indicators– such as the energy used to createand dispose of that material;the toxic releases generated; thepollution caused by transportingit; and other impacts on globalwarming – to form a detailedappraisal of that particularproduct’s environmental impact.The assessment offers architectsand builders an impartial way tocompare the environmental impactor value of various constructionmaterials. Being able to do so givesthem more flexibility in choosingthe right mix of materials to meettheir green objectives.A helpful design tool forincorporating LCA is theATHENA® EcoCalculator forAssemblies, offered free of chargefrom the Athena Institute.Originally developed for use withGreen Globes, the EcoCalculatoroffers engineers and architectsinstant life cycle assessmentresults for a variety of buildingassemblies. It can be used for newconstruction projects, retrofitsand major renovations.The EcoCalculator offers results forhundreds of common assembliesgrouped under six main categories:exterior walls, roofs, intermediate30

floors, interior walls, windows,columns and beams. Find itat www.athenasmi.ca/tools/ecoCalculator/.Why Wood?It’s easy to answer “why wood.”Beyond the broad renewablevs. nonrenewable materialslogic, in-depth science makes acompelling case.When using life cycle assessment,wood is superior to otherconstruction materials in severalkey aspects – air and water qualityand greenhouse gas emissionsamong them.Very little energy at all is used inthe life cycle of wood.The energy to grow trees comesfrom the sun and much of theenergy used to process lumbercomes from wood itself. Producingsteel and concrete requires lots offossil fuels. The production of woodreduces carbon emissions while theproduction of steel and concreteincreases carbon emissions.A 2005 study examined the impactsof lumber, plywood, strand boardand other wood-derived buildingproducts. It compared the impact ofwood to two houses, one in a coldclimate and the other in a warmclimate, one using steel frame andthe other concrete.A wood frame house in the coldclimate was compared to one inThe NewPage Corporate Headquartersbuilding in Miamisburg, Ohio achieveda rating of Three Globes from the GreenBuilding Initiative for combining innovativeenvironmental design with the functionalityof an office space.which steel was substituted forwood studs in the walls and floors.In the warm climate, a wood framehouse was compared to one inwhich concrete was substituted forwood in the exterior walls.The truth is most buildings,particularly homes, use a varietyof different materials, eachwith differing environmentalfootprints. A wood framed housesits on a concrete pad. Focusingon assemblies that feature directproduct substitution – exteriorwalls, for instance – highlights theimpact of using wood rather thansteel or concrete.31

Materials Origin and Impact — How Wood RatesUse of steel had 33 percentmore global warming impactthan wood. Steel generated 11percent more air emissions and867 percent more harmful wateremissions. The solid waste impactwas the only factor in which woodand steel were roughly equal.Similarly, concrete had 80 percentmore global warming impactthan wood. Concrete had 46percent more air emissions and164 percent higher impact onsolid waste. Concrete and woodgenerated the same amount ofwater emissions.While wood conserves moreenergy and releases fewergreenhouse gas emissions, it willstill be part of a mix of materials.Tools like the Athena InstituteEcoCalculator can help strike themost environmentally soundbalance.Understanding the Value of WoodEnvironmental performance indices for above-grade wall designsMinneapolis HouseAtlanta HouseWoodFrameWoodFrameSteelFrameConcreteFrameDifferenceDifferenceSteel vs. wood(% change)Embodied energy (GJ) 250 296 46 +18%Global warming potential (CO2 kg) 13,009 17,262 4,253 +33%Air emission index (index scale) 3,820 4,222 402 +11%Water emission index (index scale) 3 29 26 +867%Solid waste (total kg) 3,496 3181 -315 -0.9%Concretevs. wood(% change)Embodied energy (GJ) 168 231 63 +38%Global warming potential (CO2 kg) 8,345 14,982 6,637 +80%Air emission index (index scale) 2,313 3,373 1,060 +46%Water emission index (index scale) 2 2 0 0%Solid waste (total kg) 2,325 6,152 3,827 +164%A comparison of wood, steel and concrete shows wood to be an energy efficient buildingmaterial. Focusing on exterior wall assemblies that directly substitute concrete or steel for woodhighlights the environmental benefits of using wood.32

ConclusionSustainabilityReigns Supreme33

Conclusion — Sustainability Reigns SupremeWorldwide, there is a growingawareness that without carefulstewardship, the natural resourceswe depend on may be squandered.In California, sustainability is more than anabstract concept – it is an approach to conservingnatural resources and beautiful landscapes forgenerations. Increasingly, private forestland ownersare demonstrating how forest management canprovide green building materials, clean water,abundant wildlife habitat and safer forests. Managedforestlands may be the most effective scrubbers ofgreenhouse gases on the planet and can be a criticaltool in addressing global warming.Unlike other building materials, wood is renewable.Growth exceeds harvest across California and thereis roughly the same amount of forestland in theUnited States today as there was 100 years ago.34

California forestry hasbeen in the forefront ofadvancing technologyand science to sustainforest resources whilemeeting the demands ofa growing population.Wildlife biologists andhydrologists increasinglywork with foresters andarcheologists to ensureCalifornia’s forestrypractices are not onlyefficient and high techbut also ecologicallyWorld class research institutions, high-techharvesting equipment and advanced sciencehave helped establish California as a leader insustainable forestry. California’s well managedforestlands provide diverse wildlife habitat,conserve water resources and yield perhapsthe greenest building material on earth.responsible. Computer-based harvesting equipmentand milling operations have helped raise California’shigh environmental standards.Regardless of how green an architect, a builder or ahomeowner wants to be, whether they want to payfor a green rating or go green on their own, the mostsustainable choice is wood.Wood looks great, too.35

853 Lincoln Way, Suite 208Auburn, CA 956031-877-REPLANT(1-877-737-5268)www.calforests.org©2008 California Forest Products Commission