Sustainable Wood
Forest certification, reduced-formaldehyde panels build on natural qualities
The manufacturing of wood products uses fewer resources and is less polluting than other materials
by Kathy Abusow
Of all building materials, wood has the largest number of inherent green attributes. Biodegradability, carbon sequestration and renewability top an impressive list that also includes low embodied energy, low manufacturing emissions, and natural insulating properties. The largest question marks for wood in the area of green building have centred not on the material itself, but on the sustainability of forest management practices and the quality of indoor air affected by urea-formaldehyde bonded wood panels.
There are a wide variety of certification standards worldwide, just as there are many forest types and tenures. In Canada, lands are certified to at least one of three independently audited certification standards - the Canadian Standards Association’s Sustainable Forest Management Standard [CSA], the Forest Stewardship Council [FSC] and the Sustainable Forestry Initiative [SFI]. There are also three programs used in the United States - American Tree Farm System [ATFS], FSC and SFI.
There are also international endorsement programs for forest certification. FSC International endorses FSC standards developed at the regional and country level, and PEFC [Programme for the Endorsement of Forest Certification schemes] also endorses a variety of national certification programs that meet their rigorous assessment criteria. In North America, PEFC has endorsed both CSA and SFI standards.
While there are differences, the forest certification standards used in Canada and the U.S. cover the basics of responsible forest management, and go beyond this by ensuring biological diversity is conserved and wildlife habitat, soils and water resources are maintained. They all require that third-party, qualified certification bodies conduct the audits and that audit findings are publicly available. [See Table].
On the international front, CSA, FSC, PEFC and SFI all meet the sustainable procurement or marketplace acceptance requirements of the governments of the United Kingdom, France, the European Commission and Japan.
Forest certification and green building
In North America, both the Green Globes and the Leadership in Energy and Environmental Design [LEED] Green Building Rating System recognize wood products from certified forests.
Green Globes, www.greenglobes .com, is a design tool for green building that can evaluate the environmental impacts of building design choices. It recognizes a variety of credible forest certification programs including CSA, FSC and SFI.
The preference for FSC forest certification in the U.S. Green Building Council’s [USGBC] LEED Green Building Rating System would appear to be based on historic preferences rather than on current analysis. To the USGBC’s credit, it has understood the need to study the current state of the forest certification standards to help inform their decision-making and, as such, have retained professionals to develop criteria that could potentially lead to acceptance of other forest certification programs.
The USGBC has looked at recognizing other certification programs before. A few years ago the USGBC declined the Canada Green Building Council’s recommendation that the CSA and SFI standards be recognized alongside the FSC standards in the Canadian LEED products. And in 2005, when the USGBC leadership proposed several changes to LEED-NC Version 2.2 in its draft format - including recognition of CSA and SFI alongside FSC - the response from the USGBC’s environmental constituency was highly critical stating that SFI certification, for instance, allowed for clearcutting. What they neglected to communicate is, so does FSC.
A review of various FSC standards across North America shows that FSC is not synonymous with clear-cut free wood, nor old-growth free wood. The FSC Boreal Standard, for example, has no hard and fast requirements against clearcutting, nor does it contain any numeric clearcut size limitations. The FSC Boreal Standard does say the following in the guidance to the Standard, but not as a requirement of the Standard:
“Clearcut size is itself not an effective ecological indicator. Although the concept of natural disturbance emulation is becoming increasingly popular as a management concept, it is the outcome of a natural disturbance regime, and not the outcome of disturbances, that should be the focus of emulation. The amount of concern generated by clearcuts tends to increase with their size. Clearcut size determination should therefore be based on a consideration of size-dependent impacts such as wildlife movement, hydrological impacts, and effects on other forest users.”
This approach to clearcutting is not an exception for FSC standards, but nor should it be taken as a criticism of the FSC standards. It is recognition of the reality that all standards under discussion understand the need for the long term sustainability and productivity of the forest resource; and all standards being discussed ensure that special attributes or special sites are managed for their continued existence and that wildlife considerations are addressed.
While the bar can always be raised higher for forestry in North America, we have likely reached the point of diminishing returns when compared to other nations where systemic issues of illegal logging and corruption can dominate. Some of these higher-risk nations are increasing their sales to the North American marketplace, therefore, forest certification remains an excellent indicator of both legality and sustainability. With less than one-tenth of the world’s forests certified, it is safe to say that forest certification is an excellent tool for governmental, corporate and green-building decision-makers seeking to source forest products responsibly.
Other building product manufacturers are not held to the same third party audited standards for transparency, social, economic and environmental responsibility. Steel and concrete, for example, can secure a variety of points under LEED rating tools compared to wood, and yet they do not offer voluntary certification to assure customers of responsible resource management and sourcing.
Independent life-cycle assessments, such as those conducted by the ATHENA™ Institute [www. athenasmi.ca], rank wood as the leader across a variety of environmental attributes when compared to steel and concrete, provided that wood comes from a well-managed source. CSA, FSC, PEFC and SFI certification standards provide that assurance.
Kathy Abusow is principal of Ottawa-based Abusow International Limited, a forest certification and market acceptance consultancy. abusow@sympatico.ca.
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wood and sustainable building
Life-cycle assessment sheds new light
by Linda McPhee
Life-cycle assessment [LCA] is the recognized international approach to assess the environmental merits of products or processes as set out in the ISO 14000 series of standards.
LCA includes the entire life cycle of a product, process, or activity, from extracting and processing raw materials to manufacturing, transportation and distribution, use, maintenance, recycling and final disposition.
Based on LCA, wood products have proven to be one of the most environmentally responsible building products.
In the concept of cradle to cradle, where materials are designed to be returned safely to the soil or to flow back to industry to be used again, wood is a material that can be recycled or reused and ultimately is biodegradable. With good forest management practices, sustainable wood can make the strongest of claims as a sustainable building material.
Following are excerpts from a comparative environmental impact LCA assessment of embodied and operating energy of three hypothetical but typical single family homes in Toronto. The study was conducted by the ATHENA™ Sustainable Materials Institute for the Canadian Wood Council.
The LCA study considered different construction materials in the three hypothetical homes, though all were similar in outward appearance and size. One is designed using lumber and engineered wood I-joist framing, the second design incorporates light frame steel for its structure, and the third design uses insulated concrete forms [ICF] and a composite concrete slab on steel joists.
The assessment results were summarized into six key measures covering total primary energy [operating and embodied energy, where embodied energy includes the direct and indirect energy associated with extraction, manufacturing, on-site construction and maintenance and repair activities during the first 20 years of operating these homes], global warming potential, air pollution, water pollution, resource use, and solid waste.
The Institute retained engineers Morrison Hershfield to review the drawings and material lists for accuracy, gauge the comparative “fairness” of the alternative designs, and assist in entering assembly and material data into the ATHENA™ EIE model. Morrison Hershfield also completed the operating energy simulation for the three material designs.
Summary of Results
Summing the total embodied and operating energy for 20 years for each design, and then comparing these overall results relative to the wood design, indicates that both the steel and concrete designs respectively:
- embody and consume 12% and 20% more energy;
- emit 15% and 29% more greenhouse gases;
- release 10% and 12% more air pollution;
- discharge 3 and 2.25 times more water pollution;
- use 7% and 50% more resources from a weighted resource use perspective; and
- produce 6% and 16% more solid wastes,
Another way of looking at these results is to compare them on the basis of years of operating energy and related greenhouse gas releases saved by building the wood design [the lower embodied design] over the steel and concrete designs.
In the first 20 years, the savings attributable to building the wood home are equivalent to about 2.5 years of operating energy and 3.6 years of global warming gas emissions in the case of the steel design, and 5.5 years of operating energy and 8.6 years of global warming gas emissions in the case of the concrete design.
For more information visit the ATHENATM Sustainable Materials Institute at www.athenasmi.ca and the National Renewable Energy Laboratory at www.nrel.gov/lci.
Linda McPhee is Director, Sustainable Building with the Canadian Wood Council in Ottawa.
How wood contributes to LEED
Of the 70 points outlined in the LEED® Canada Standard, 17 are relevant to wood. The certified wood credit [MRc7] encourages environmentally responsible forest management by recognizing wood and wood products certified under the standards of the Forest Stewardship Council, the only forest certification standard currently recognized by LEED. Projects qualifying for the certified wood credit may be able to achieve other wood-related points using the same product. The four top credits most often combined with MRc7are: recycled content [MRc4], the use of local materials [MRc5], rapidly renewable materials [MRc6] and low emitting materials [IEQc4].
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