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What Makes a Building Product Green


The key component of any green project is you, the design/build professional. GreenSpec provides you with independent research to assess which top performing green products can help turn a good building into a great one.

GreenSpec uses five high-level environmental performance criteria to determine which building products rank among the greenest 10% of all products in their categories.

To be included in our database, a product not only must meet one or more of these performance criteria, it must also meet a set of rigorous requirements—including specific green certifications, performance thresholds, and other measures of quality—tailored to the product category against which the product is evaluated.

To learn more about which GreenSpec environmental criteria are most relevant to specific categories, click on a category at left.


  1. Products made with salvaged, recycled, or agricultural waste content

    The materials used to produce a building product—and where those materials came from—is a key determinant of green.

    1. Salvaged products

      Whenever we can reuse a product instead of producing a new one from raw materials—even if those raw materials are recycled—we save on resource use and energy. Many salvaged materials used in buildings (bricks, millwork, framing lumber, plumbing fixtures, and period hardware) are sold on a local or regional basis by salvage yards. Fewer salvaged materials are marketed widely, and it is generally only these that are profiled in a national directory such as GreenSpec. Local and regional green product directories can really shine when it comes to finding salvaged materials.

    2. Products with post-consumer recycled content

      Recycled content is an important feature of many green products. From an environmental standpoint, post-consumer is preferable to pre-consumer recycled content, because post-consumer recycled materials are more likely to be diverted from landfills. For most product categories, there is currently no set standard for the percentage of recycled content required to qualify for inclusion in GreenSpec, but such standards will increasingly be developed in the future. In some cases, products with recycled content are included with caveats regarding where they should be used. Rubber flooring made from recycled automobile tires is a good example—the caveat is that these products should not be used in most fully enclosed indoor spaces due to offgassing concerns. In certain situations, from a life-cycle perspective, recycling has downsides. For example, energy consumption or pollution may be a concern with some collection programs or recycling processes. Also, closed-loop recycling is generally preferable to downcycling, in which a lower-grade material is produced. As more complete life-cycle information on recycled materials—and the process of recycling—becomes available, we intend to scrutinize recycled products more carefully.

    3. Products with pre-consumer recycled content

      Pre-consumer (also called “post-industrial”) recycling refers to the use of industrial by-products, as distinguished from material that has been in consumer use. Iron-ore slag used to make mineral wool insulation, fly ash used to make concrete, and PVC scrap from pipe manufacture used to make shingles are examples of post-industrial recycled materials. Usually excluded from this category is the use of scrap within the same manufacturing process from which it was generated—material that would typically have gone back into the manufacturing process anyway. While post-consumer recycled content is better than pre-consumer recycled content, the latter can still qualify a product for inclusion in GreenSpec in many product categories—especially those where there are no products available with post-consumer recycled content.

    4. Products made from agricultural waste material

      A number of products are included in GreenSpec because they are derived from agricultural waste products. Most of these are made from straw—the stems left after harvesting cereal grains. Citrus oil, a waste product from orange and lemon juice extraction, is also used in some green products, but such products usually include other agricultural oils as well and are lumped under 2d – Rapidly renewable products.

  2. Products that conserve natural resources

    Aside from salvaged or recycled content, there are a number of other ways that products can contribute to the conservation of natural resources. These include products that serve a function using less material than the standard solution, products that are especially durable and therefore won’t need replacement as often, products made from FSC-certified wood, and products made from rapidly renewable resources.

    1. Products that reduce material use

      Products meeting this criteria may not be distinctly green on their own but are included in GreenSpec because of resource efficiency benefits that they make possible. For example, drywall clips allow the elimination of corner studs, engineered stair stringers reduce lumber waste, pier foundation systems minimize concrete use, and concrete pigments can turn concrete slabs into attractive finished floors, eliminating the need for conventional finish flooring.

    2. Products with exceptional durability or low maintenance requirements

      These products are environmentally attractive because they need to be replaced less frequently, or their maintenance has very low impact. Sometimes, durability is a contributing factor to the green designation but not enough to distinguish the product as green on its own. This criterion is highly variable by product type. Included in this category are such products as fiber-cement siding, fiberglass windows, slate shingles, and vitrified-clay waste pipe.

    3. Certified wood products

      Third-party forest certification, based on standards developed by the Forest Stewardship Council (FSC), is the best way to ensure that wood products come from well-managed forests. Wood products must go through a chain-of-custody certification process to carry an FSC stamp. Manufactured wood products can meet the FSC certification requirements with less than 100% certified wood content through percentage-based claims. With a few special-case exceptions, any nonsalvaged solid-wood product and most other wood products must be FSC-certified to be included in GreenSpec. A few manufactured wood products, including engineered lumber and particleboard or MDF, can be included if they have other environmental advantages—such as absence of formaldehyde binders. Engineered wood products in GreenSpec do not qualify by virtue of their resource efficiency benefits alone (for more on this, see EBN Vol. 8, No. 11).

    4. Rapidly renewable products

      Rapidly renewable materials are distinguished from wood by the shorter harvest rotation—typically 10 years or less. They are biodegradable, often (but not always) low in VOC emissions, and generally produced from agricultural crops. Because sunlight is generally the primary energy input (via photosynthesis), these products may be less energy-intensive to produce—though transportation and processing energy use must be considered. Examples include linoleum, form-release agents made from plant oils, natural paints, geotextile fabrics from coir and jute, cork, and such textiles as organic cotton, wool, and sisal. Note that not all rapidly renewable materials are included in GreenSpec—non-organic cotton, for example, is highly pesticide-intensive. In some cases, even though a product qualifies for GreenSpec by virtue of its natural raw materials, it may have negatives that render it inappropriate for certain uses—such as high VOC levels that cause problems for people with chemical sensitivities.

  3. Products that avoid toxic or other emissions

    Some building products are considered green because they have low manufacturing impacts, because they are alternatives to conventional products made from chemicals considered problematic, or because they facilitate a reduction in polluting emissions from building maintenance. In the GreenSpec criteria, a few product components were singled out for avoidance in most cases: substances that deplete stratospheric ozone, and those associated with ecological or health hazards including mercury and halogenated compounds. In a few cases, these substances may be included in a “green” product if that product has significant environmental benefits (for example, low energy or water use). These substitutes for products made with environmentally hazardous components may not, in themselves, be particularly green (i.e., they may be petrochemical-based or relatively high in VOCs), but relative to the products being replaced they can be considered green. Most of the products satisfying this criterion are in categories that are dominated by the more harmful products. We have created several subcategories here for green products:

    1. Natural or minimally processed products

      Products that are natural or minimally processed can be green because of low energy use and low risk of chemical releases during manufacture. These can include wood products, agricultural or nonagricultural plant products, and mineral products such as natural stone and slate shingles.

    2. Alternatives to hazardous products

      Some materials provide a better alternative in an application dominated by products for which there are concerns about toxic constituents, intermediaries, or by-products. Fluorescent lamps with low mercury levels are included here, along with form release agents that won’t contaminate water or soils with toxicants. Also included here are alternatives to products made with chlorinated hydrocarbons such as polyvinyl chloride (PVC) and brominated fire retardants.

    3. Products that reduce or eliminate pesticide treatments

      Periodic pesticide treatment around buildings can be a significant health and environmental hazard. The use of certain products can obviate the need for pesticide treatments, and such products are therefore considered green. Examples include physical termite barriers, borate-treated building products, and bait systems that eliminate the need for broad-based pesticide application.

    4. Products that reduce stormwater pollution

      Porous paving products and green (vegetated) roofing systems result in less stormwater runoff and thereby reduce surface water pollution. Stormwater treatment systems reduce pollutant levels in any water that is released.

    5. Products that reduce impacts from construction or demolition activities

      Included here are various erosion-control products, foundation products that eliminate the need for excavation, and exterior stains that result in lower VOC emissions into the atmosphere. Fluorescent lamp and ballast recyclers and low-mercury fluorescent lamps reduce environmental impacts during demolition (as well as renovation).

    6. Products that reduce pollution or waste from operations

      Alternative wastewater disposal systems reduce groundwater pollution by decomposing organic wastes or removing nutrients more effectively. Masonry fireplaces burn fuel-wood more completely with fewer emissions than conventional fireplaces and wood stoves. Recycling bins and compost systems enable occupants to reduce their solid waste generation.

  4. Products that save energy or water

    The ongoing environmental impacts that result from energy and water used in operating a building often far outweigh the impacts associated with building it. Many products are included in GreenSpec for these benefits. There are several quite distinct subcategories:

    1. Building components that reduce heating and cooling loads

      Examples include structural insulated panels (SIPs), insulated concrete forms (ICFs), autoclaved aerated concrete (AAC) blocks, and high-performance windows and glazings. As these energy-saving products gain market acceptance, our threshold for inclusion in GreenSpec may become more stringent. For example, we may begin including only SIPs and ICFs with steady-state R-values above a certain threshold or with other environmental features, such as recycled-content foam insulation. Some products, such as insulation, clearly offer environmental benefits but are so common that they need other environmental features to qualify for GreenSpec. In the case of windows, the base standard for energy performance of windows is an NFRC-rated unit U-factor of 0.25 or lower for at least one product in a listed product line. If the windows are made from an environmentally attractive material (e.g., high recycled content or superb durability), the energy standard is less stringent: U-factor of 0.30 or lower. If the frame material is nongreen, such as PVC (vinyl), the energy standard is more stringent: U-factor of 0.20 or lower. There are a few exceptions to these standards, such as high-recycled-content windows made for unheated buildings.

    2. Equipment that conserves energy and manages loads

      With energy-consuming equipment, such as water heaters and refrigerators, we have good data on energy consumption and can set clear standards accordingly. In most product categories—e.g., refrigerators, dishwashers, and clothes washers—we set higher thresholds than Energy Star®: for example, exceeding those standards by 10% or 20%. With lighting and lighting control equipment, certain generic products qualify, such as compact fluorescent lamps and occupancy/daylighting controls, while in other categories only a subset of products qualify. (See table for GreenSpec standards for certain types of equipment.) In some cases, products that meet the energy efficiency requirements are excluded, because of evidence of poor performance or durability. Microturbines are included here because of the potential for cogeneration (combined heat and power) that they offer. Ice- or chilled-water thermal energy storage (TES) equipment is also included because it helps reduce peak loads, which in turn can reduce energy costs and lower the impact of electricity generation.

    3. Renewable energy and fuel cell equipment

      Equipment and products that enable us to use renewable energy instead of fossil fuels and conventional electricity are highly beneficial from an environmental standpoint. Examples include solar water heaters, photovoltaic systems, and wind turbines. Fuel cells are also included here, even though fuel cells today nearly always use natural gas or another fossil fuel as the hydrogen source—they are considered green because emissions are lower than combustion-based equipment and because the use of fuel cells will help us eventually move beyond fossil fuel dependence.

    4. Fixtures and equipment that conserve water

      All toilets and most showerheads today meet the federal water efficiency standards, but not all of these products perform satisfactorily. With toilets and showerheads we include products that meet the federal standards and have dependably good performance. We include in GreenSpec only toilets that offer at least 20% water savings, compared with the federal standard of 1.6 gallons per flush (gpf), and we have adopted the Maximum Performance (MaP) standard for the performance of most toilets—requiring a minimum rating of 65 grams of test media removal per liter of flush volume. Some other products, such as rainwater catchment systems, are also included.

  5. Products that contribute to a safe, healthy built environment

    Buildings should be healthy to live or work in and around, and product selection is a significant determinant of indoor environment quality. Green building products that help to ensure a healthy built environment can be separated into several categories:

    1. Products that do not release significant pollutants into the building

      Included here are zero- and low-VOC paints, caulks, and adhesives, as well as products with very low emissions, such as nonformaldehyde manufactured wood products. Just how low the VOC level needs to be for a given product to qualify for inclusion in GreenSpec depends on the product category. Ideally those standards should be based not on simple VOC content, but on resultant VOC concentrations in the space after a given period of time—EPA is working on such data for paints (including a way to factor in higher impacts for more toxic VOCs), but this information is not yet available.

    2. Products that block the introduction, development, or spread of indoor contaminants

      Certain materials and products are green because they prevent the generation or introduction of pollutants—especially biological contaminants—into occupied space. Duct mastic, for example, can block the entry of mold-laden air or insulation fibers into a duct system. “Track-off” systems for entryways help to remove pollutants from the shoes of people entering. Coated ductboard—compared with standard rigid fiberglass ductboard—prevents fiber shedding and helps control mold growth. And linoleum helps to control microbial growth because of the ongoing process of linoleic acid oxidation.

    3. Products that remove indoor pollutants

      Qualifying for inclusion here are certain ventilation products, filters, radon mitigation equipment, and other equipment and devices that help to remove pollutants or introduce fresh air. Because ventilation equipment is now fairly standard, only products that are particularly efficient or quiet, or that have other environmental benefits are included.

    4. Products that warn occupants of health hazards in the building

      Included here are carbon monoxide (CO) detectors, lead paint test kits, and other IAQ test kits. Because CO detectors are so common, other features are needed to qualify such products for GreenSpec, such as evidence of superb performance.

    5. Products that improve light quality

      There is a growing body of evidence that natural daylight is beneficial to our health and productivity (see EBN Vol. 8, No. 9). Products that enable us to bring daylight into a building, including tubular skylights, specialized commercial skylights, and fiber-optic daylighting systems, are included in GreenSpec. Some other products, such as full-spectrum lighting systems and highly reflective ceiling panels, could also be included in GreenSpec under this criterion.

    6. Products that help control noise

      Noise, both from indoor and outside sources, adds to stress and discomfort. A wide range of products are available to help absorb noise, prevent it from spreading, masking it, and even reducing it with sound-cancellation technologies.

    7. Products that enhance community well-being

      Looking beyond the walls of a building, many products can contribute to safer neighborhoods, increasing walkability and making high-density communities appealing.


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