Abstract

Specification in nonresidential buildings

The government of the province of Quebec, Canada, expressed in 2008 the intention to promote the use of wood in nonresidential buildings (Béchard 2008). In buildings, wood utilization is usually related to structural materials. However, a broad range of wood building material is used for interior finishing, including wood floor covering, decorative wall paneling, ceiling tile, sidings, and mouldings (Robichaud and Lavoie 2010, Drouin et al. 2012). Those materials have an aesthetic function and are often used in large volumes. They also show high added value and represent an application of choice for wood products.

Studies have been published on the development of wood use in nonresidential construction among building professionals in Canada (Fell and Lavoie 2009, Robichaud and Lavoie 2010, Drouin et al. 2012). From these studies, with a specification rate of 66 percent, wooden doors were identified as the most specified appearance wood product by architects. The least specified appearance wood product was wooden windows with 23 percent of nonresidential construction projects. These studies also show that wooden doors are more likely than other appearance wood products to be specified in the Canadian National Building Code (CNBC) class B2 buildings for care and detention (physical and cognitive limitations) and commercial buildings (CNBC class E). Finally, it was shown that the use of appearance wood products, such as millwork, cabinetry, floor covering, and exterior and interior siding, vary in an inversely proportional manner to the built area. On the other hand, products such as windows, doors, and stairs are specified independently from the designed building area. It should be noted that the main limitation for the interior use of wood products in large construction is maintenance.

Environmental profile

In wood-based appearance products manufacturing, adhesives, glues, coatings or paints, stains, and varnishes are commonly used and may contain VOCs. Among VOC-emitting adhesives, the most mentioned is formaldehyde and its derivatives, which are known to have negative effects on human health (Mølhave et al. 1995, Irigaray et al. 2007, An et al. 2010, Gminski et al. 2010). Furthermore, additives, such as halogen-based flame retardant, fungicides, pesticides, and other biocides, improve the material's durability against fire, decay, or mold and are potentially detrimental to human health and result in negative environmental impact (Mølhave et al. 1995, Irigaray et al. 2007).

Werner and Richter (2007) reviewed life‐cycle research on wood building products. Conclusions pointed to wood products having a better environmental profile compared with functionally equivalent products made of alternative materials. One of the worst cases for wood products is the impregnation with metal-based preservatives, which appears to be more critical with respect to toxicological effects and/or photochemical oxidation. Incineration of wood products caused higher impacts of acidification and eutrophication than other products in spite of thermal energy recovery. The review of Werner and Richter (2007) also revealed that wood composites, such as particleboard or fiberboard, resulted in higher raw material yield compared with solid wood products. However, the consumption of fossil fuel associated with the production of raw fibers and particles as well as the production of resin and additives were very high.

Finally, various environmental studies have been conducted on interior appearance wood products, but the context of residential buildings is generally considered. Appearance products that have been analyzed are mainly wooden floor coverings, followed by wood-based furniture and doors (Knight et al. 2005; Nebel et al. 2006; O'Connor 2009; González-García et al. 2011, 2012a, 2012b; Mahalle 2011; Cobut et al. 2015b). The present study proposes to address the lack of environmental information for this type of product, taking into account the nonresidential construction contexts.

Appearance wood products family selection

In order to represent the interior appearance wood products family in the context of nonresidential construction, key products were selected. Previous qualitative Canadian research projects described their specification rate in nonresidential building projects (Fell and Lavoie 2009, Robichaud et al. 2009, Drouin et al. 2012). Consequently, selecting key products was done according to these results. The products representing the interior appearance wood products family for this study are doors, office furniture, mouldings, architectural paneling, and floor covering. Products are presented in details in Table 1 and displayed in Figure 1.

Table 1 Presentation of selected interior appearance wood products for nonresidential applications.

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The choice of raw materials was made to represent practices among appearance wood products manufacturers in eastern Canada, more specifically in the province of Quebec. For that reason, hardwood species selected for the manufacture of most parts of the mentioned products are sugar maple and yellow birch. The door design is based on a manufacturing company based in the province of Quebec. The office desk design was chosen according to data collected from two Canadian manufacturers of office furniture Web sites, Teknion and Global Contract. Wall paneling composition was decided after consulting a manufacturing company in the province of Quebec. Mouldings and floor covering compositions were chosen according to specifications from field experts.

Environmental profile establishment and generalization

The door environmental case study, presented in Cobut et al. (2015a, 2015b), was used through extrapolation to establish the environmental profile of the interior appearance wood products family. The study should be viewed as generalizing previous findings obtained for interior wooden doors, instead of performing complete LCA for each segment of the studied family of products. LCA results from the door case study were analyzed and adapted based on life‐cycle processes similarities and differences among the product family.

Extrapolation process

The extrapolation process to expand on Cobut et al. (2015b) was split into three steps. The first step consisted of identifying the similarities and differences between unit processes used in the door case study compared with the other products of the family, as presented in Tables 1 and 2. The raw material constituting each product from this product family was identified. The raw material of each product was then compared with the raw material found in the door assembly. Then the same procedure was carried out for all other life‐cycle stages. It was decided that shipping and the end of life would be the same for all product categories, as in the wooden door case study scenario. Packaging differs for flooring products because additional cardboard is used. Consequently, the use phase is also different for flooring products because they include packaging waste management.

Table 2 Similarities among raw material processes.^a

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The second step of impact extrapolation was the modeling of ecoinvent unit processes not used in the case study. This is the case for a majority of components (Table 2) and some life‐cycle stages shown in Table 3. When processes were different from the door system, it was decided to model the environmental impacts of each appropriate unit process in SimaPro with IMPACT 2002+ and export the results in the extrapolation data set. This was done for medium-density fiberboard (MDF), acrylic coating, alkyd paint, polyurethane, phenol-formaldehyde resins, and cardboard for packaging.

Table 3 Similarities among remaining life-cycle stages.^a

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The third step was the calculation of impacts for each product of the family using a common functional unit. The functional unit used was the coverage of the door system already studied, which was an area of 1.92 m². For flooring products, the amounts of additional cardboard, resins, and coating were taken from the work of Mahalle (2011). The amount of polyvinyl acetate (in grams per square meter) needed for assembling products, such as paneling and office desks, was assumed to be equal to the amount of glue in the door system per square meter.

Life‐cycle stage contributions and product weight

When looking at Figure 2, in terms of stage contributions, it is quite obvious that the acquisition and transformation of raw material have the highest contribution to the total environmental impact regardless of the product. Slightly negative contributions found in each product profile for the EQ category are owing to the avoidance of virgin raw material usage in the particleboard manufacturing process through the recycling of trimmings and sanding by-products.

Glues and coatings

From the door study and from all extrapolated impacts, the contribution of glues in assemblies and coatings to total environmental impacts seems negligible in comparison to the contributions of resins in composite panel production. Nevertheless, in the case of lighter products, such as engineered wood flooring, the contributions of glues and coatings were noticeably higher compared with what was observed in other products. In fact, the weight of coatings and glues is, in general, dominated largely by the weight of wood components. Engineered wood flooring is an exception because of its lower thickness combined with a higher use of coatings for a higher resistance and product longevity. Also, the use of plywood that requires a noticeable amount of glue is also responsible for those results. In the end, glues and coatings still represent a more significant impact contribution in lightweight products.

Solid wood and veneer versus wood composites

Environmental profiles differ between composite-based and solid wood– and veneer-based products. The main reason lies in the type of wood raw materials. For solid wood or veneer products, the required quantity and quality of wood lead to a higher impact on EQ owing to wood selection specificities. In contrast, composite-based products are usually made of residues from the aforementioned processes, so the impact on EQ is of lesser importance. It is logical to see higher scores and contributions for solid wood– and veneer-based products in Figure 2 compared with composites in the EQ category. On the other hand, composite-based products have greater impacts and contributions on CC and R damage categories. Based on Cobut et al. (2015b), resins and additives, as well as processing energy consumption needed for composite board production such as particleboard, high-density fiberboard (HDF), and MDF, have important impacts on CC and R. Considering the HH category, it appears that composite-based products and solid wood– and veneer-based products have similar environmental impact patterns.

Wood-based modular playground

González-García et al. (2012a) studied the environmental profile and the ecodesign potential of a wood-based modular playground. The impacts were analyzed from cradle to gate. The main wood material in their products was Scandinavian solid pine (50% of total weight), three-layered laminated board (25% of total weight), and plywood (12% of total weight). The environmental impact assessment (EIA) methodology used was CML 2 Baseline 2000 v2.1 biogenic. As a main contributor to the total environmental impacts, they found the assembling stage had a contribution of from 60 to 83 percent, depending on the impact category. Assembling comprises raw material, such as wood boards, solid timber, metal and plastic pieces, and raw materials transportation. These results are quite similar to what was found in this research, except metal and plastic pieces were not part of our inventory. Packaging had a higher contribution in the study of González-García et al. (2012a) because of the presence of cardboard, and many impacts were also because of metal pieces that were not present in this research. Plastic pieces and lacquering were not noticeable contributors to the total impact.

Indoor furniture for children

In another study, environmental profile and ecodesign of an interior wood product were analyzed, from cradle to gate, by González-García et al. (2012b). The product was a set of indoor furniture for children. The main components were wood materials, such as solid timber (less than 5% of product weight), MDF (nearly 10% of product weight), and particleboard (at least 80% of product weight). The same EIA methodology as in the modular playground study was used (González-García et al. 2012a). The main LCA results were again very similar to the results of the present study, even though the EIA methodology is somehow different from that of the Cobut et al. (2015b) study. Raw materials were found to be the most contributive to total environmental impacts of the product. The particleboard was the main contributor to the raw materials impacts because of its proportion in the product composition, just as in the door case study (Cobut et al. 2015b). Extrapolation results presented in the current study are hence in accordance with the work of González-García et al. 2012a, 2012b).

Floor coverings

Different types of floor coverings, including hardwood flooring, were studied by Mahalle (2011). The study was performed from cradle to grave. A modified version of North American TRACI methodology, CO₂ from air being accounted for as a negative emission to include CO₂ sequestration by forests, has been used as well as the cumulative energy demand method. As for prefinished hardwood flooring, the main findings suggest that the manufacturing stage was the dominant stage in terms of energy and environmental flows. It consumes 72 percent of total energy and emits 30 to 76 percent of environmental emissions among the chosen categories. The manufacturing stage consisted of drying green lumber, milling operations (planning, ripping, trimming, and moulding), and finishing operations (coating and packaging). The drying process was the most contributive to the manufacturing stage. It was also the most energy intensive with 75 percent of energy consumption on a cradle-to-gate basis. Moreover, drying was responsible for most of the greenhouse gas emissions. Finally, drying contributed significantly to all other impact categories compared with the two other manufacturing processes. These results again confirm that raw materials acquisition and transformation are large contributors to the products' environmental impacts as identified by the results from the current study.

Wood building products

Werner and Richter (2007) made a literature review on comparative LCA studies performed on wood building products. From their review, it appears that composite wood products, such as particleboard, HDF, or MDF, obtain a better roundwood yield compared with solid wood products. However, there is generally a very high consumption of fossil energy associated with the production of fibers and chips as well as of resins or additives. The same observations have been made in the door LCA study (Cobut et al. 2015b). They also pointed out that methods used for the impact assessment, at the time of their study, did not allow consideration of the impacts of forests, such as land occupation, impacts on biodiversity, purification of air, and other environmental services. The depiction of toxicological effects of chemical components is also criticized because both existing methodologies and the model structure of LCA do not allow spatial or temporal resolution. These limitations were also observed later in Cobut et al. (2015b).

Wood coatings

The environmental profile of four types of wood coatings has been studied by Gustafsson and Börjesson (2007). They studied two wax-based coatings—rapeseed oil–derived wax and paraffin-derived wax—and two UV cured coatings—one water based and the other 100 percent solid. An LCA from cradle to grave of these four coatings was performed using a common functional unit. The study revealed that the most environmentally friendly alternative was the 100 percent solid UV coating. In fact, the most contributive life‐cycle stage was the production of ingredients as well as the application and drying of coatings for which the productive country electricity grid mix could play an additional role in coating global warming impacts. It was seen in a sensitivity analysis that coatings applied or dried under a coal-based electricity grid mix, like in Poland, had a higher global warming score than under a hydro-based and nuclear-based electricity grid mix, like in Sweden. Gustafsson and Börjesson (2007) results led to the exploration of issues of ecodesign, which is done in the next section.

Board design

Particleboards and MDF are the main components for products such as doors, office desks, architectural paneling, and composite mouldings. They also are the most contributory components to those products' environmental impacts. Four types of solutions addressing board design are considered.

Lightweight panels

Another ecodesign option that was not mentioned in the door study is replacing particleboard or MDF core with a lighter core. That could be interesting for the office desk, the heaviest product of this group. By reducing the weight of problematic components, their associated environmental impact may be reduced. This could also decrease transport impacts that are calculated on a ton-per-kilometer basis.

There is scientific literature discussing and companies producing boards that can be used for the furniture and door industry as lightweight substitutes for MDF and particleboard. Lightweight panels can be distinguished into conventional wood-based panels with reduced density by lower compaction of the mat or low-density raw materials; tubular boards; sandwich panels with a homogeneous core layer, such as foam core; and sandwich panels with a heterogeneous core layer, such as honeycomb panels. Figure 3 illustrates several types of lightweight panels. These panels are less present in North America than in Europe and are still subjects of research (Thoemen 2008, Sam-Brew 2010, Shalbafan 2013). In general, the reduced weight in panels comes with lower mechanical properties and higher production costs compared with conventional wood panels (Thoemen 2008). Lightweight panels can be up to 75 percent lighter than regular wood boards (Sam-Brew 2010, Cascades Inc. 2013). The highest benefits from lightweight panels may be seen in the transportation of both raw materials and shipping. A reduction of a component's weight is a reduction of both freight costs and freight environmental impacts. Once again, on a whole life‐cycle basis, durability of the products, considering their lower mechanical properties, should be considered in their footprint.

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Forest product companies, such as DendroLight, are starting to produce interesting panel cores from cellular solid wood ranging in density from 260 to 477 kg/m³ (Bell 2013a, DendroLight 2013a). Different DendroLight panels are presented in Figure 4. Their products have the advantage of not containing resin. Other advantages that concern mostly interior wood doors are that the door-specific panels are fire rated at 30 minutes and present good acoustic performance with a sound insulation up to 35 dB (DendroLight 2013b). A version of these panels exists also for tabletops and may be suited for office desks (DendroLight 2013c). No formal environmental studies have ever been performed on these products, but interesting diminutions in weight-associated impacts can be foreseen.

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Lightweight panels may be particularly interesting for heavy products, such as doors or office desks, but a life‐cycle analysis could determine their true environmental benefits. It seems essential that manufacturers should be able to make informed decisions, especially when selecting environmentally responsible suppliers, because their raw material choices can definitely have a large influence on the final product environmental profile, especially when the main component is a composite.

Transportation

In the door case study, it was observed that changing transport mode could provide environmental impact reductions on the order of 30 percent of overall transportation impacts (Cobut et al. 2015a). However, these reductions were relatively minor (a maximum of 9% for HH) in comparison to the overall life‐cycle door impacts.

Nevertheless, sensitivity analysis results show that shipping characteristics can have a substantial influence on the LCA results of all studied appearance wood products (Cobut et al. 2015a). For instance, a decrease of truck loading by 25 and 50 percent increases the contribution of the shipping stage, thus exceeding that of the end of life. On the contrary, increasing the loading by 25 percent diminishes the environmental impacts of the shipping phase. Appearance wood products often need extra space owing to packaging to preserve integrity and quality during shipping. This results in higher environmental impacts at the shipping stage. It is then important to consider this parameter when trying to decrease the environmental burden of the product.

As with truck loading, the same observations were made for shipping distances when raised by 100 percent for road transportation and 300 percent for rail transportation (Cobut et al. 2015a). The shipping phase becomes the second most contributive stage to the product's life cycle. Therefore, as rail freight has less environmental impacts than road freight, it should be preferred for longer distances.

In summary, transportation parameters can have substantial impacts on the LCA results of products, and decisions should be made accordingly, whether it is by managing shipping logistics differently (including packaging and loading), promoting shipping by rail, or finding local area suppliers whenever possible or applicable.

Packaging environmental contribution in lighter appearance wood products

With a special view to lighter appearance products or developing lighter panel use, packaging options should be assessed more thoroughly because their contribution to the total environmental impact is inversely proportional to weight. In González-García et al. (2012b), the question of packaging was also investigated. The substitution of plastic bags with cardboard shows interesting impact reductions as well as the use of recycled plastic materials. Therefore, these solutions could also be applied in the studied context.

Reuse and remanufacturing

For the door, the remanufacturing option with the core assembly reutilization exhibited the largest benefits in terms of environmental damage reduction over the whole life cycle (Cobut et al. 2015a). One reuse of the core assembly permitted saving at least 25 percent of the original score regardless of the damage category. Remanufacturing is a short-term option that does not require investing in new technologies or changing suppliers. However, it does involve the implementation of reverse logistics networks.

Remanufacturing could be a reasonable end-of-life option to reduce office desk and architectural paneling impacts. However, the high degree of customization in architectural paneling may bring supplementary difficulties in reuse and reverse logistics. Moreover, highly customized products may not be fitted for remanufacturing since they meet very specific demand for specific functions and building configurations. To counter the problem of high customization, pieces of sanded MDF panels, depending on their conditions, may be reused in the production of other architectural panels of different sizes. Moreover, an office desk has a different fastening system that may require more inspection and attention for remanufacturing. On the other hand, these specific fasteners may make disassembly of the desks into their components easier. The use of standard fasteners can improve the reusability of such products.

For composite moulding, remanufacturing may not be as straightforward as in the previous cases, if possible at all. The value of composite mouldings, in comparison to solid wood mouldings, might not justify the implementation and use of a remanufacturing process. However, composite mouldings could be sanded and shaped to serve as backup or filler raw materials. It could be used, for example, as raw material input for nonconventional-size wood products, including MDF components of different shapes and forms, such as in cabinetry or paneling. This process is already used in the studied door manufacturing plant (Cobut et al. 2015a). Unused particleboard parts serve as raw material input for doors to reach higher and nonstandard dimensions without extra board costs. In addition, González-García et al. (2012b) mentioned the reuse of internal wastes in order to decrease the environmental impacts of products. It was observed that the higher the recycling rate, the greater the environmental benefits (González-García et al. 2012b).

The use of postconsumer boards such as MDF and particleboard as raw materials in composite panels manufacture is also an option (Composite Panel Association 2012). However, the quantity of contaminated wood cannot be over 2 and 10 percent by weight for MDF and particleboard, respectively (Clean Washington Center 2001, 2002).

In any case, the redirection of wood products from landfills and their reintroduction into other similar product life cycles have a high probability of success in reducing the product environmental footprint.

Energy generation

Composite-based products may not be suited for energy generation because they are identified as contaminated waste. In general, contaminated wood is used less frequently or in smaller quantities owing to widespread concern over its potential to produce air contaminants. The option can be one of choice, though, when using a proper high-temperature furnace with a high filtering capacity, considering the interesting results obtained when substituting fuel oil for heat production (Cobut et al. 2015a). Besides, several sources mention that in the context of the province of Quebec, energy production from wood wastes may not be as beneficial environmentally and economically as in other jurisdictions because of the low cost and availability of renewable hydroelectricity (Laurent et al. 2011, Gouvernement du Québec 2013).

Sustainable wood resource

As solid wood–based appearance products are believed to have a significant impact on the quality of ecosystems compared with composites, it seems legitimate to ensure that solid wood is sourced from sustainable forest practices. The use of certified wood is a valid option for that matter. Information on sustainable forestry certification programs is available in Gulbrandsen (2004), Ozinga and Krul (2004), Cashore et al. (2005), Wingate and McFarlane (2005), Hansen et al. (2006), ITS Global (2011), Cobut et al. (2012), and Tikina et al. (2012).

Freight and local sourcing

For minimizing freight environmental impacts linked to raw materials acquisition, it is important to deal with local solid wood and chemicals suppliers. Optimizing logistics in order to minimize overall transport and the transport footprint is of importance. For all life‐cycle stages, the use of rail or waterway freight, wherever possible and available, decreases the environmental impacts linked to shipping compared with conventional truck transportation, according to Horvath (2006).

Packaging and coatings

Packaging strategies, mentioned for composite-based appearance wood products, still stand for solid wood– and veneer-based appearance wood products. For engineered wood flooring, the contributions of UV coating and glues have taken a higher share than in all previous appearance products environmental profiles. Even though the applied UV coating contribution is nonnegligible, a study has shown that 100 percent UV coating is the most environmentally friendly option considering its resistance to wear compared with solvent-based UV coatings and wax-based coatings (Gustafsson and Börjesson 2007). Replacing chemical nonrenewable resources with renewable ones could enhance their environmental profile. However, it is necessary to ensure, through a life‐cycle analysis, that such substitution brings real environmental benefits.

Reuse and remanufacturing

Architectural woodwork was often valued for its character and beauty, making it a prime candidate for salvage and reuse (Jeffrey 2011). Therefore, the cost of salvaging architectural woodwork is easier to justify during the demolition process because of the prohibitive costs associated with its reproduction. Reclaiming wood is actually a growing industry. This market appeal lies in the material's environmental story and history, its unique visual patina, and its strength and stability (Bell 2012). Furthermore, landfilling wood construction waste has been banished in the province of Québec since 2014 (Ministère du Développement durable, de l'Environnement et des Parcs [MDDEP, currently MDDELCC] 2012). In the case of hardwood mouldings, salvaging appears to be one viable end-of-life option. The diversion from landfill will avoid greenhouse gas production and substitute virgin solid wood production, in the end reducing related raw material impacts. Reclaiming hardwood floors is actually more common than is seen for other wood products. Hardwood floors can be recovered for more versatile applications than hardwood mouldings due to their shapes and sizes. Wall coverings, furniture, and floor coverings are potential applications. Innovation in the installation system, possibly through clickable systems, could enhance the recovery potential of hardwood floorings.

To summarize, additional care should be brought to hardwood mouldings and hardwood and engineered wood floors during removal to maximize their recovery potential. Innovations in the installation system may also help enhance this potential.

Recycling

If hardwood mouldings or flooring are not worth being kept in the same condition because of deterioration or wear, they could easily be used as raw materials for other products. It is easier, of course, when they are free of finishes or glue. For that, it would be recommended to sand them before removal. Textured wood walls are potentially interesting for reusing hardwood waste as tiles because of their value and quality. It is also interesting to notice that textured wood wall markets are emerging in North America (Bell 2013b). Other applications that use reclaimed wood are potentially interesting for reusing hardwood mouldings. All of these remain niche applications and need further commercial development.

Energy generation

Energy generation from hardwood-based product waste is conceivable, especially when the solid wood is free as much as possible of contaminants, such as glues and finishes. In some facilities, wood wastes used for fuel are tested to ensure that contaminant levels are kept at the required level (Jeffrey 2011). Negative impacts of contaminated wood wastes can be controlled through the use of proper high-temperature and high-filtration furnaces. The use of clean waste wood as a fuel source for heat and electricity production is a well-established practice in many countries, including Canada and the United States (Jeffrey 2011). Several studies established that postconsumer wood recovery for energy generation is beneficial for net greenhouse gas reduction mostly when substituting fossil energy (Jungmeier et al. 2003, Sathre and O'Connor 2010, Laurent et al. 2011, Cobut et al. 2015a). Jungmeier et al. (2003) are very specific about the fact that using this kind of bioenergy, although generating a substitution benefit, it is not CO₂ free, and there is a need to assess through proper LCA all energy production from wood waste before making decisions. As an example, in the context of the province of Quebec, there are benefits when such projects substitute diesel or bunker energy production, but not when substituting hydroelectricity. The last question to be addressed is whether it is economically profitable to use high-value products such as hardwood flooring or hardwood moulding for energy generation in comparison to reuse or remanufacturing options.

Life‐cycle environmental impacts calculation methodology

Finally, methodological choices such as the use of IMPACT 2002+ damage categories and data adapted to North America and the province of Quebec bring more limitations to the presented findings. One such limitation certainly lies in the high level of controversy on the capacity of IMPACT 2002+ to assess correctly the diversity of forest management situations for the EQ impact end-point indicator. For all wood products, this is a serious limitation because the raw material procurement stage is in all products the main contributing factor.

Biogenic carbon

The carbon stored in wood products has not been accounted for and added in our model. The ecoinvent database, used for LCA, has been selected to assess wood products processes. However, the carbon storage benefit from carbon storage in wood products is not accounted for in the LCA results because IMPACT 2002+ does not take into account carbon intake when calculating environmental impacts. This is a limitation in the LCA methodology. Many scientists assess this benefit becaues it does exist, but it is not yet encompassed in LCA methodology.

Wood products in landfills have a slow rate of decomposition, and deposition in landfills is widely considered as a means to enhance carbon storage, assuming that landfill gases are recovered properly (Skog 2008, Sathre and O'Connor 2010, Larson et al. 2012). Nevertheless, in this study, appearance wood products disposal in a sanitary landfill was not considered as carbon storage, following the assumptions of the used impact evaluation methodology of IMPACT 2002+. Thus, it is fair to expect that accounting for carbon storage during landfilling may improve the environmental record of the end of life to the total score of appearance wood products, which may balance waste transportation impacts to the landfill site.