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Following is my summary and critique of the USGBC's LEED Building Design & Construction Reference Guide, v4. Commentary on the Reference Guide can be found in these red boxes, sometimes within each of the chapter links immediately above, but also in my summary and critique of the prior versions: Version 2.2 NC and Version 3.0.
Reducing embodied energy is just one of many environmental impacts typically measured using life-cycle assessment (see discussion below); it's not clear why only embodied energy is mentioned here.
Diversion of waste from landfill does nothing to encourage the optimal strategy of "source reduction." In fact, LEED continues to effectively margnalize source reduction by providing credits (points) for less effective recycling and reuse strategies.
Life Cycle "Assessment" (LCA):
This overview does not mention "cradle to gate" (where the LCA ends at the factory "gate," and does not even consider any subsequent environmental impacts) even though this minimal form of LCA actually shows up as a requirement in one of the credits.
LCA is fraught with problems, as it attempts to evaluate the environmental impact of various activities by "adding" their impacts together in order to arrive at some sort of numerical value. Unfortunately, such impacts — including things like global warming potential, acidification, and so forth — cannot be rationally added together unless they are reduced to some common metric (which is a subjective and politically-charged act). More importantly, LEED's list of "LCA impact indicators" is hardly exhaustive, and includes only 6 items for consideration: global warming, ozone depletion, acidification, eutrophication, tropospheric ozone, and nonrenewable energy depletion, the first five of which are the "life cycle-impact assessments" (LCIA) sanctioned by ISO 21930:2007 (Environmental Declaration of Building Products) while the sixth is derived from the list of "life-cycle inventory" (LCI) items sanctioned by ISO 21930. Even environmental issues mentioned in other LEED sections (e.g., preservation of wetlands, maintenance of the nocturnal environment, disposal of mercury, etc.) are excluded from consideration, except indirectly. Remarkably, the life cycle measurement of "embodied energy," mentioned in the overview of this section, does not show up in the actual credit.
What is a "product"?
LEED's contradictory explanation of the product-content of concrete is that each component of concrete "serves a different function" (but then, so do the various components of gypsum wallboard, which are not each considered as "products"). Of course, given the way in which prior versions of the LEED rating system were "tweaked" in order to increase the apparent value of fly ash, it's quite possible that this dubious distinction concerning the constituent ingredients of concrete is just a ploy to give another boost to what otherwise would be characterized as a single product.
And so on and so forth: glossy paint is a separate product compared with flat paint; but red and blue paint constitute a single product.
Intent: Reduce landfill waste.
Requirements: Collection/storage area provided in building for recycling materials. In addition to dealing with paper, cardboard, glass, plastics, and metals, this prerequisite also mandates dealing with two of the following three things: batteries, lamps with mercury, and e-waste.
Intent: Reduce landfill waste originating from construction or demolition debris.
Requirements: Make a plan that considers at least 5 "material streams" (excluding land-clearing debris). That's all: just make a plan.
Intent: Improve "environmental performance" of materials/products; encourage adaptive reuse of buildings.
Requirements: There are four options, only one of which can be (needs to be) satisfied to get points.
The alleged value of building reuse, rather than new construction, is based in part on a 2011 report on The Greenest Building cited in the v4 Reference Guide. This report shows that impacts of Global Warming Potential (GWP) are, or are not, mitigated by reuse (as opposed to more energy-efficient new construction) depending on the climate, the type of occupancy, and the number of years that new construction would need to be in place to offset the carbon costs of demolition and construction — i.e., the GWP impact mitigation of new construction, based on its more efficient energy profile, requires anywhere from 10 to 80 years (or "never" in the case of warehouse conversions into residential uses) of lifespan. Aside from the enormous variation in outcomes, and in spite of the limited environmental impacts considered (GWP only), what this type of study completely neglects to consider is the global growth of fossil-fuel-derived energy use. Whether an individual project chooses to reuse and renovate, rather than building new, is a useless metric for assessing global environmental impacts, since the sheer mass of new projects, whether adaptive reuse or new construction — and therefore the continual increase in fossil fuel use and greenhouse gas emissions — renders such distinctions moot.
OPTION 1: Reuse a historic building.
One gets 5 points simply by using a historic building, and leaving intact its historic features. What constitutes a historic building, and to what extent alterations are permitted, is a function of various official "listings" and their requirements.
OPTION 2: Fix up and use an abandoned (or "blighted") building.
First, the criteria for whether a building is abandoned or blighted is left to the local jurisdiction. Second, the criteria for achieving 5 points is that at least 50% of the structure and enclosure is kept — after demolishing up to 25% on the basis of "deterioration or damage."
OPTION 3: Reuse building materials.
Just salvage (reuse) building material, whether it originates on site or off site. Lots of fussy documentation is required, since the criteria for achieving points is based on the surface area of salvaged stuff compared with the total surface area of stuff in the completed building. Windows and hazardous materials are allowed to be excluded (this makes it easier to achieve the credit, since a smaller total surface areas is thereby allowed in the denominator of the equation). One gets between 2 and 4 points as follows: 2 points for 25% salvaged material; 3 points for 50%; and 4 points for at least 75%.
OPTION 4: Conduct a life-cycle assessment (LCA) of the building.
One gets 3 points for producing an LCA that includes only the building structure and enclosure. To get these 3 points, the LCA has only to show a 10% reduction in global warming potential and 2 of 5 other impacts, compared to a so-called "baseline" building. For the baseline building, the envelope is as defined by ASHRAE 90.1-2010, Appendix G (various sections), although the geometry of the baseline building need not be the same as that of the actual building, so the various quantities of materials in the building envelope may not be consistently measured. The baseline building is tweaked and altered to create the actual building design, but the following parameters must not change: LCA scope; total floor area; occupancy (function); basic orientation (although the shape/geometry can vary); site/climate; and ASHRAE requirements cited above. The five other impacts in addition to GWP, as listed above, are ozone depletion, acidification, eutrophication, tropospheric ozone, and nonrenewable energy depletion. To get the 3 points, none of the 6 impacts can exceed the baseline by more than 5%.
Various LCA calculators can be used, including one that can be downloaded for free (for PCs only*), created by Athena Sustainable Materials Institute.
* As of April 3, 2014, Athena is providing a free, remote, reservation-based service for Mac users.
In other words, one can make a building that exceeds baseline limits for half of the listed environmental impacts, and still achieve 3 points. And of course, it is possible to damage the environment without penalty in innumerable other ways — not even considered within the six categories listed in this credit. Thus, the U.S. Department of Defense, known for despoiling environments in countries around the world, has been the biggest client of the LEED rating system. Finally, the ASHRAE standards cited above were designed to create a baseline for measuring energy cost savings in a proposed building — they have no interest in, nor any means for assessing, LCA impacts. Therefore, there is no guarantee that a baseline building used in the LEED credits (for LCA-related credits) is in any way an environmentally-meritorious starting point. And if the baseline has no documented merit, then a 10% improvement over it has no particular environmental significance. Ten percent better than bad may still be bad.
Intent: Encourages the use of products/materials that are environmentally sound, based on life-cycle assessment (LCA) documentation produced by product/material manufacturers.
Requirements: There are two options, each worth a point, and each independent of the other, so that both may be achieved.
OPTION 1: [For 1 point] A building must contain at least 20 "products" (what exactly constitutes a product is specified in the criteria below, but at least 5 different manufacturers of such products must be included) meeting one of the following three criteria concerning how the environmental impact of the product is "disclosed" by the manufacturer:
OPTION 2: [For 1 point] Instead of, or in addition to, adding up the number of products (or half, or quarter products), this option allows a computation based on cost. Specifically, the point is achieved if at least 50% of the cost of products used in the building is derived from products that are either certified to have lower-than-industry-average impacts in three of these LCA categories (GWP, ODP, acidification, eutrophication, or tropospheric ozone), or comply with other USGBC-approved EPD programs.
This is a remarkably weak criteria: even the 50% of products meeting this standard could have huge deficiencies in terms of, say, global warming potential and tropospheric ozone — a gaseous component of smog — while only barely beating "industry-average" levels of all the other negative impacts; while the non-compliant 50% of products can have unlimited LCA deficiencies. Not only that, there is no interest in the quantity of such products in relation to the building size, so that even a tiny, token area of some certified material counts as a "product" in these calculations, encouraging the purchase of needless finishes, for example, just to achieve additional points.
But the real problem with this option is more fundamental: measuring environmental impact by cost makes no sense, if the goal is to establish a useful metric for actually understanding and mitigating environmental impacts. A product might be quite expensive while having only marginal benefits, but it could single-handedly contribute to the achievement of this credit option nevertheless. One must assume that the strategists at USGBC view this, not as a serious methodology to assess and reduce negative environmental impacts, but as a market-transforming tool to encourage and reward manufacturers who use LCAs to create EPDs. However, there are still two problems with this approach. First, actual standards are set so low that achieving the credit has virtually no relationship to mitigation of environmental impacts. Second, and more important, by measuring only one building at a time, LEED ignores completely the net environmental impact of all global construction — this total global impact can neither be measured, mitigated, nor controlled when individual property owners make economic decisions (as capitalist businesses within a competitive marketplace) entirely on the basis of increasing profit by lowering costs of production. The public-relations benefit of "green" products is certainly factored into such calculations, but cannot change the basic calculus: despite the wishful thinking of USGBC and its apologists who imagine that for-profit enterprises make decisions based on social and environmental impacts in addition to financial impacts, there is simply no such thing as a triple bottom line — I'll say a bit more about the "TBL" or "3BL" myth in MR Credit 3.
Products created entirely within a 100-mile radius measured from the project site (formerly a 500-mile radius in previous incarnations of the LEED guidelines) can be considered as twice as expensive within this option, while products constituting structure and enclosure are limited to 30% of the total cost of products that can be considered.
One minor note about the cost calculations (which applies to other MR credits as well): The LEED Reference Guide's "calculation" worksheets are presumably intended to place a scientific/mathematical veneer over what is otherwise a vapid and illogical methodology — consisting in this case of the addition and multiplication of a few numbers, converting the "word problems" spelled out in the credit descriptions to "number problems." The calculation for Option 2 gives an extra "bonus" to products whose "location valuation factor" or "criterion valuation factor" is greater than one by applying this bonus only in the numerator, and not in the denominator of the fraction from which the required percentage is found. For example, if a building consists of two products, with Product A having a cost of $100, meeting the criteria for Option 2, and having a location valuation factor of 2 (because it is manufactured within 100 miles of the building site) and with Product B having a cost of $300 but not meeting the criteria for Option 2, then the weighted percentage of A with respect to (A + B) would normally be computed as: [100x2 / (100X2 + 300)] x 100 = 40%. This percentage is less than 50% and so the credit would not be achieved. However, LEED permits the denominator of the fraction to exclude all valuation factors, so the percentage is computed as: [100x2 / (100 + 300)] x 100 = 50%, achieving the credit. In other words, the actual cost of Product A is 25% of the total cost, the "normal" weighted cost of Product A is 40% of the total cost, while the "LEED" weighted cost of Product A is 50% of the total cost.
In fairness to these LEED calculation methods, it should be admitted that — since the entire premise of using cost is flawed — it really is of no consequence that the actual method of working with these "cost valuation factors" has little internal coherence. The absurdity of such calculations can be seen by replacing Product A with a Product C that is manufactured 10,000 miles from the project site and, like Product A, satisfies the criteria for Option 2 (the environmental impacts of transporting the product 10,000 miles are excluded from consideration in these "cradle to gate" calculations). In this scenario, we assume that Product C costs twice as much as Product A. In spite of any number of differences in environmental impact, nothing changes in Equation 2; the 50% criteria is still met: [200 / (100 + 300)] x 100 = 50%. Cost rules!
Intent: Encourages the use of products/materials that meet "triple bottom line" criteria and, in particular, have been extracted or "sourced" in a "responsible manner."
The so-called triple bottom line presumes that businesses may make decisions on the basis, not only of profitability, but also on the basis of environmental or social considerations. This is clearly false, since only profitability ensures the survival ("sustainability") of the business within a competitive capitalist marketplace. Any social or environmental efforts that reduce profitability threaten the viability of the business itself, and therefore would never be undertaken. Social or environmental measures enter into the marketplace via governmental regulations that apply to all businesses (e.g., clean air act or child labor laws). That businesses may decide to enter a market niche with environmental or socially-conscious attributes has nothing to do with any triple bottom line: rather, such businesses have simply decided to compete within a market — still governed by the single "bottom-line" criterion of profitability — in which environmental or social factors are recognized as opportunities for making money.
The "bottom line" is, literally, the bottom line of a business ledger in which expenses and income are tabulated; a positive value on the bottom line indicates profit. In this literal sense, a business could well create some sort of "social" and "environmental" ledger, in which expenses and social/environmental outcomes were tabulated, and a triple bottom line could thus be established. The problem with this concept is two-fold. First, all "expenses" devoted to social or environmental causes would, by definition, show up in the "financial" ledger, since the investment of capital — for whatever reason — is a financial matter: it is not possible to remove "social" or "environmental" expenses from the financial bottom line calculation. Second, the bottom line concept — taken literally — is simply a measure of whether the business is "in the black" or "in the red." From this neutral standpoint, a social or environmental "bottom line" could similarly attempt to measure the social or environmental impacts for which the business is responsible. However, such a "neutral" reading of the bottom line — as a mere tool for measuring various parameters — misses the actual meaning that the term has come to embody: it is not simply a tool for measuring impacts, but an imperative to successfully compete by taking all viable measures to cut costs of production and improve profitability. The bottom line is the life or death struggle for survival that compels businesses to search the globe for the cheapest sources of labor, materials, and energy. It is in this latter sense that the concept of a triple bottom line is meaningless, since there are no such "life or death" factors that compel businesses to achieve particular social or environmental outcomes. Instead, all such noble endeavors are quickly transformed into line items within the financial ledger, justified by any number of business calculations concerning the economic value of well-publicized good deeds.
Requirements:There are two options, both of which can be achieved for a total of 2 points:
OPTION 1: [For 1 point] A building must contain at least 20 "products" (what exactly constitutes a product is specified in the criteria below, but at least 5 different manufacturers of such products must be included) for which the "responsible" extraction of raw materials is documented. Self-declared documentation counts as a half product, while third-party "corporate sustainability reports" (CSR) count as full products. Various organizations are listed that can sanction such CSRs.
OPTION 2: [For 1 point] Another point can be earned by proving that products accounting for at least 25% of product costs in the building meet one or more of these criteria:
This is another example of the inappropriateness of "cost" as a metric for sustainable behavior. Since the actual cost of salvaged material may be quite low, or even free, LEED allows the actual cost to be replaced by the potentially higher cost of a new product. Why? Because the lower the actual cost of such beneficial materials, the lower its sustainable valuation, according to the "logic" of the marketplace endorsed by LEED in this credit. LEED therefore is forced to sabotage its own market-driven ideology by artificially increasing the costs of salvaged material so that the "sustainable" value of such salvaged material is, well... salvaged!
The logic for this distinction doesn't seem to be explained in the Reference Guide, but presumably has to do with the assumption that postconsumer waste has a greater potential downside than preconsumer waste, since the former, if not recycled, will end up in a landfill (or worse), while the latter — being within a manufacturing process in which waste is predictable and some sort of profitable recycling is more likely — presents less of an environmental problem. Except for the piles of preconsumer contaminated coal ash that ended up in the Dan River in North Carolina — but that's another story.
The Table 1 "sample calculation" in LEED's example of an MDF Panel with FSC-certified veneer seems to ignore the "preconsumer penalty," by giving the locally sourced MDF core (valued at $9,000, of which 80%, or $7,200, is preconsumer recycled content) a "sustainable criteria value" of $7,200 X 2 = $14,400. In this calculation, the $7,200 is multiplied by 2 to account for its local origins and manufacture, but it also should be divided by 2 to account for the fact that it's preconsumer, rather than postconsumer, recycled content. The fact that this $9,000 value is determined by the relative weight of the MDF core is also a bit strange, since the FSC-certified veneer is presumably quite a bit more valuable/expensive than its 10% weight would indicate. But getting the actual costs right still does nothing to make the calculation more rational vis-à-vis environmental impact or sustainability. If rationality is the goal, these procedures are merely cumbersome and time-intensive, but otherwise pretty much useless.
As before, products created entirely within a 100-mile radius measured from the project site can be considered as twice as expensive within this option, while products constituting structure and enclosure are limited to 30% of the total cost of products that can be considered.
Intent: Encourages the use of products/materials that meet "triple bottom line" criteria [see red box comments above] and, in particular, limit the amount of harmful substances used in the product, and provide better life cycle assessment (LCA) outcomes.
Requirements: There are three options, each worth 1 point. The stated total limit for this credit is 2 points, even though 3 points seem possible by adding up the points gained in the separate options, which are as follows:
OPTION 1: [For 1 point] A building must contain at least 20 "products" (in this case, there are no half- or quarter-products, but at least 5 different manufacturers of such products must be included) where various programs are implemented to measure chemical composition at an accuracy of at least 1000 parts per million (ppm). Acceptable methodologies include disclosing a "manufacturer inventory" of chemical content using Chemical Abstract Service Registration Numbers (CASRN), except that "trade secrets" and "intellectual property" need not be specifically identified as long as their "role, amount and GreenScreen benchmark" are disclosed. Other acceptable methodologies are the "Health Product Declaration" standard; "Cradle to Cradle" v2 basic or v3 bronze level; or an approved USGBC program.
OPTION 2: [For 1 point] Here, we have one of two "cost-based" options, this one requiring that 25% of materials (measured by a weighted cost, as noted below, plus an additional "double-cost" bonus where sourced within 100 miles of the project site) have documented material ingredient "optimization" based on:
OPTION 3: [For 1 point] This is the other "cost-based" option, requiring that 25% of materials (measured by the actual cost, except that costs are doubled for products extracted and manufactured within 100 miles of the project site) meet both of these two criteria:
While 99% may seem like a large percentage, it allows enormous quantities of hazardous substances, such as mercury [pdf], to be used within these "green" products, as such ingredients often consist of far less than 1% of the total product weight while still posing enormous hazards in the aggregate. The LEED credits for mercury, lead, cadmium, and copper reduction apply only to healthcare facilities, and are optional — like all LEED credits — in any case. There is also a "mercury lamps" option (one of three choices of which two need to be picked) in Prerequisite 1.
According to LEED instructions for this credit, products satisfying either Option 2 or Option 3 can be combined to reach the 25% cost threshold, but any given product can only be counted in one of these two "cost-based" options. This, at first glance, would appear to make it somewhat more difficult to satisfy the criteria for all three Options. But it still seems technically possible to satisfy all three options and thereby gain 3 points: for example, Product A could represent 25% of product costs and satisfy Option 2; while Product B could represent 25% of product costs and satisfy Option 3; and Products A, B, C, D, etc. could satisfy the criteria for Option 1 (20 products whose ingredients are measured...). However, the "step-by-step" explanation reiterates that only 2 points are possible for this credit. Products constituting structure and enclosure are limited to 30% of the total cost of products that can be considered in Options 2 and 3.
Intent: Like Prerequisite 2, the intent is to reduce landfill waste originating from construction or demolition debris.
Requirements: There are two options for compliance, all of which exclude land-clearing debris or excavated soil. Wood that is not recycled, but rather burned as fuel, can be considered; whereas other "waste-to-energy" materials cannot be counted unless they comply with European standards promulgated by the European Commission (2008/98/EC and 2000/76/EC) and the European Committee for Standardization (EN 303). The options, only one of which may be selected, and which are based on the "plan" created in the corresponding prerequisite, are as follows:
OPTION 1: [For 1-2 points] For 1 point, 50% of construction/demolition waste material (measured either by weight or volume) must be recycled in a minimum of 3 "streams" (e.g., plastics, clean wood, metal, carpet, paper/cardboard, gypsum wallboard — mis-labeled as "Sheetrock" in Table 1 of this LEED credit — brick/concrete masonry, asphalt shingles); for 2 points, 75% must be recycled in 4 streams minimum.
OPTION 2: [For 2 points] For 2 points, and as an option to validating the impact of recycling based on the fraction of waste not reaching a landfill, one can achieve this credit by showing that no more than 2-1/2 pounds of construction waste are generated for each square foot of building floor area. As an example, a building with 50,000 square feet of floor area is permitted, under this option, to create 62.5 tons of landfill-bound construction debris.
The lack of coherence in these credits is evident in the two options for construction waste mitigation. If the second option is too rigorous, limiting the amount of construction waste based on the building's size, the first option can generate the same number of points irrespective of the amount of waste that ends up in a landfill, especially if, and to the extent that it eludes the primary goal of source control. Take the 50,000 square foot building used as an example above. Let's say that instead of creating 62.5 tons of construction waste (and thereby satisfying the criterion for Option 2), we create ten times that amount — 625 tons of waste, or 25 pounds for each square foot of floor area. It's still possible to gain 2 points under Option 1, "path 2," as long as 75% of this waste, or 469 tons, is "diverted" from landfill. In other words, 156 tons of waste could still be headed for a landfill — more than twice the amount allowed under Option 2 — but the two points are still awarded. In fact, there are no limits to how much construction/demolition waste can end up in a landfill while still gaining points under Option 1: all that is required is to implement as little source control as possible, thereby increasing both the amount of waste generated and the amount of waste that can be sent to the landfill while still complying with the credit's requirements.
It is also possible to game the system by using either a "volume" metric or a "weight" metric, since certain recyclable materials are much lighter than others relative to their volume (e.g., paper, plastics, clean wood compared to concrete scrap). For example, if we had 10 cubic yards of recyclable corrugated cardboard, 10 cubic yards of recyclable concrete scrap, and 25 cubic yards of some other non-recyclable waste material weighing 18,500 lbs, we couldn't gain any points under Option 2 if we measured by volume: (10 + 10) / (10 + 10 + 25) = 44% diversion (less than the required 50%). However, if we use the weight metric, the calculation turns out to be more favorable: 1000 lbs of cardboard + 18,550 lbs of concrete / (1000 + 18,500 + 18,500) = 51%, achieving the credit. On the other hand, if the non-recyclable waste material consisted instead of 15 cubic yards, weighing 20,000 lbs, the volume calculation turns out to be favorable — (10 + 10) / (10 + 10 + 15) = 57% — while the weight calculation doesn't work out — 1000 lbs of cardboard + 18,550 lbs of concrete / (1000 + 18,500 + 20,000) = 49%. Taking this "logic" to its extreme, if a project's waste calculations, based on recycling a number of different streams — including clean wood — showed that only 49%, or only 74%, of the waste qualified, one could simply order an extra truckload of lumber and immediately transfer it to the recycling bins, thereby reaching the desired threshold for achieving 1 or 2 points under this credit while demonstrating one's commitment to "green" building practices, all for a relatively small cost.
First posted 8 July 2014; last updated 20 April 2016