Greening the Built Environment
Greening the Built Environment
ASTM Standards and Products Form the Foundation of Sustainable Construction Efforts
Today, a major focal point for the worldwide building industry is the growing demand for sustainable construction. Sustainable, or "green," construction is focused on the more effective use of resources and ultimately the creation of healthier, energy efficient, more environmentally friendly homes and buildings.
This move toward sustainability is transforming the way the industry designs, constructs and operates buildings. Evidence of this shift abounds, whether it's the growth of green roofing systems atop office buildings in major international cities or the steady rise in green construction in the residential housing market. According to a study by industry research firm McGraw-Hill Construction, green housing projects accounted for 20 percent of all newly built homes in 2012 and had an overall value of $25 billion. The firm estimates that this share will grow to between 29 and 39 percent of new U.S. homes by 2016.
As momentum toward green construction increases, standards and other technically based solutions from ASTM International will continue to fulfill the goals of the building industry and the needs of consumers. More than 200 ASTM standards make a valuable contribution throughout all areas of the sustainable built environment. These standards and new ASTM activities in the field of sustainability help guide the design and construction of green buildings.
ASTM Standards: Technical Foundation of Codes and Rating Systems
ASTM International standards play a critical role in the growth of sustainable buildings through the green building rating and certification programs embraced by the global construction industry. These programs assist stakeholders in navigating the often complex field of sustainability, defining the attributes of green buildings and guiding environmentally responsive practices.
One such effort is the International Green Construction Code. Developed by the International Code Council, the IgCC is the first model code to include sustainability measures for the entire construction project and its site - from design through construction, certificate of occupancy and beyond. For both new and existing buildings, the IgCC provides model code language related to energy conservation, water efficiency, site impact, building waste, material resource efficiency and other sustainability measures.
ASTM International is one of five cooperating sponsors of the IgCC, and the latest version of the code, released in 2012, cites more than 40 ASTM standards covering various aspects of building construction. Among these are ASTM green construction standards such as E2399 on green roof systems, C1549 on solar reflectance and E2635 on water conservation in buildings. Thirteen ASTM technical committees have standards referenced in the IgCC on topics ranging from air quality to thermal insulation.
Another major green building certification system worldwide is LEED, Leadership in Energy and Environmental Design, developed by the U.S. Green Building Council. Architects, contractors, material suppliers, realtors and facility managers rely on LEED in the design, construction and operations of commercial buildings, houses, schools and more. LEED addresses the entire building life cycle and recognizes best-in-class building strategies, and it provides third-party verification for green buildings. Every day, more than 1.5 million square feet (.14 Mm2) of space is certified using LEED. The latest version of the program, LEED v4, was approved in July 2013. ASTM International standards, as well as those from other leading standards developing organizations, play an important part in establishing performance criteria for various components of the LEED initiative.
ASTM Committee E60: Leading the Way in Sustainability Standards
Formed in 2008, ASTM International Committee E60 on Sustainability is a significant contributor of technically sound, market-relevant standards addressing the fields of sustainability and sustainable development. Standards for the built environment are developed by Subcommittee E60.01 on Buildings and Construction, which has a portfolio of 15 specifications, test methods and guides. E60.01's earliest efforts focused on bringing greater clarity and establishing common language on sustainability relative to the performance of buildings. This work led to the release of one of the committee's first standards – E2114 on terminology for sustainability, which promotes more effective communications among industry stakeholders. Similar utility is offered in E2432 on general principles of sustainability, which defines three general sustainability principles - environmental, economic and social - and identifies the core methodologies associated with the decision making process used in pursuing sustainability.
Another important focus for Subcommittee E60.01 pertains to the selection of building products for sustainable construction. To further assist stakeholders involved in these activities, E60.01 provides E2129 on assessing the sustainability of building products. This valuable practice covers a set of instructions for collecting data to be used in evaluating the sustainability of building products for use in both commercial and residential buildings.
Advancing Innovation in Green Roofing Systems
Recent activity in ASTM Subcommittee E60.01 has been aimed at a dynamic and growing aspect of sustainable building construction: green roofs. The development and installation of sustainable roofing systems is increasing on a wide range of buildings, from industrial facilities to private residences. A green roof, or rooftop garden, is a vegetative layer grown on a rooftop. Green roofs provide shade and remove heat from the air, reducing temperatures of the roof surface and the surrounding air; reduce air pollution and greenhouse gas emissions; enhance stormwater management and water quality; and improve the aesthetics of both office buildings and homes.
Vegetative green roof designs fall into two general categories: those with sedums or drought-tolerant plants for extensive vegetative green roofs and complete landscape gardens for intensive vegetative green roofs. In either approach, green roofs help fulfill core goals of sustainable construction.
The implementation of green roof systems involves a broad array of design, material selection, installation and maintenance considerations. ASTM E60.01 has taken the lead in meeting the market's need for substantive guidance in green roof systems, developing six standards covering considerations such as structural design, water permeability, system performance, irrigation requirements, plant and related material selection, and other requirements. Among these standards is E2399 on green roof systems, which provides designers with an objective test method for replicating field conditions on green roofs and evaluating performance prior to implementation. Selection of plant material is also crucial for the success of a green roof system since a rooftop is an extreme environment with strong and variable wind patterns and little or no protection from the sun's heat and ultraviolet radiation. E2400 on the selection, installation and maintenance of plants for green roof systems lends a valuable assist in this area, offering recommendations for choosing, planting and irrigating plants grown on vegetative grown roofs.
E60.01 standards have helped bring down early adopter costs, spurring the implementation of green roofs in the United States and abroad. The committee is further building on its efforts with a proposed comprehensive guide on green roof systems that is currently under development. When approved, the new E60.01 standard will offer architects and other stakeholders a complete approach to the design, planning and implementation of vegetative green roofs. It will also help practitioners identify the characteristics and concepts of green roof systems consistent with the core sustainability principles outlined in ASTM E2432.
Green roofing systems are also an important component of the standards writing agenda of ASTM International Committee D08 on Roofing and Waterproofing. Through the efforts of Subcommittee D08.24 on Sustainability, six new standards for various aspects of sustainable roofing systems are currently under development. This work includes two new guides focusing on vegetative green roof design and materials selection.
Another important green construction area that D08 is addressing is "cool" roofs, a green roofing approach that responds to the sun's solar energy by reflecting its heat and emitting its radiation back into the atmosphere. A variety of cool roof materials, including asphalt shingles, metal, reflective coatings, roofing membranes and roofing tiles, helps mitigate the sun's effect. When less heat is absorbed into a building's interior, occupants benefit from lower air-conditioning energy use and a more controllable and constant indoor environment.
Cool roof techniques can be used in low-slope roofs, which have relatively flat rooflines and are installed atop institutional, commercial, industrial, office, retail and multifamily buildings; and steep-slope roofs, which have an inclined roofline and are generally used on single family homes. Two standards developed by Subcommittee D08.18 on Nonbituminous Organic Roof Coverings play a valuable role in assisting stakeholders in the implementation of cool roof systems. ASTM standards E1918 on solar reflectance and E1980 for calculating solar reflectance index help building designers and consumers in choosing the cool roof materials most suitable to their specific building requirements.
Solar Energy: Powering Green Buildings
In the last several years, buildings with rooftop solar arrays have become increasingly commonplace. According to the global consultancy McKinsey & Company, technological leaps and the scaled-up production of solar panels have made solar power dramatically less expensive. What started as a technology used to power satellites, telescopes and other vehicles in outer space is now used in homes, office buildings and warehouses, and even in the form of solar farms covering acres of land.
For home and commercial facility owners, solar offers a clean energy source that leads to lower utility bills, independence from the traditional power grid and a reduced carbon footprint. The growing demand is driving green builders to incorporate the installation of solar arrays in their design and construction projects. Supporting their efforts are numerous test methods, practices and guides developed by ASTM International Committee E44 on Solar, Geothermal and Other Alternative Energy Sources. E44 has a growing set of standards touching on a wide range of clean energy applications. Assisting green builders are ASTM standards such as E2766 on the installation of roof-mounted photovoltaic arrays. E2766 details the requirements for the installation of solar arrays on steep-sloped roofs, including proper water-shedding integration with the roof system and flashing of roof penetrations.
To help measure the solar reflectance of their products, manufacturers of glass, coatings, films and optical components of solar energy systems rely on ASTM standard E903 on solar absorptance, reflectance and transmittance of materials. This test method helps manufacturers assess the reliability, durability and performance of these components in order to optimize the entire materials system performance.
Impacting Green Building Materials
A green home is much more than the sum of its parts - it also reflects its impact on the environment for as long as it stands. Green builders are compelled to pay closer attention to all the details that come into play during a building's entire life cycle - including where it is built, how many resources it consumes, how it affects the environment and what materials go into its construction. Negative environmental impacts can be minimized through responsible and intentional use and application of green materials. Products that contain a high percentage of rapidly renewable resources have a lighter environmental footprint and are strongly encouraged in the LEED rating system. Material durability is also an important consideration in green buildings as using durable materials reduces life cycle costs and limits environmental impacts.
Numerous ASTM technical committees are driving the development of high quality, environmentally friendly materials that support green construction. A significant contribution is being made by Subcommittee D18.14 on Geotechnics of Sustainable Construction, which is part of ASTM International Committee D18 on Soil and Rock. D18.14 has a trio of current standards for using industrial byproducts with earth materials in sustainable construction. Among these is D7760 on tire-derived aggregates, a construction material produced from recycled vehicle tires. TDA can be used as an alternative to stone aggregate in various construction-related applications, including lightweight backfill behind building foundations and retaining walls. D7760 supports the testing of hydraulic conductivity, which is required in various civil engineering applications of TDA.
D7762 on self-cementing fly ash guides the use of coal fly ash in the stabilization of soils to limit the settlement of fills below buildings. Similar goals are being achieved with D7765 on foundry sand, which covers methods and recommendations on the reuse of green foundry sands - discarded by the foundry industry - in embankment and structural fill applications.
Another group impacting the development of green building materials is Subcommittee D20.20 on Plastic Lumber, part of ASTM Committee D20 on Plastics. This subcommittee's efforts are helping advance the utility of plastic lumber products in sustainable construction. As an alternative for treated lumber, plastic lumber products resist insects, rot, moisture and many chemicals. These products take the form of composites, such as wood products made from a mix of plastics and natural fibers, and wood-like products made solely from plastics. Many of these products benefit the environment by using recycled plastics, thereby reducing the amount of waste generation throughout municipalities.
Several D20.20 standards, such as D6108 on compressive properties of plastic lumber and D6109 on flexural properties of plastic lumber, provide stakeholders with methods for testing how products will perform in conditions similar to the targeted construction setting, aiding quality control and material selection. Another notable D20.20 performance standard is D6662 on polyolefin-based plastic lumber, which covers products made from recycled polyolefin plastics for use as exterior residential decking boards.
Standards from ASTM International Committee D07 on Wood also have an important stake in the development of materials use in green construction. These include D5456 on structural composite lumber products and E1333 on air and emission rates from wood products, both of which are referenced in the IgCC. E1333 helps test for the emission of formaldehyde, a colorless, pungent chemical used in the manufacture of building materials, protecting building occupants from the potentially detrimental health effects of overexposure to this gas.
Standards from ASTM International Committee C16 on Thermal Insulation also assist in the development of products and systems that make buildings more energy efficient, reduce utility costs and increase occupant comfort. An important green building material addressed by C16 standards is cellulose insulation, an efficient, nontoxic and affordable thermal solution made from post-consumer recycled newsprint, paper and cardboard. Cellulose has numerous attributes for use in green construction projects owing to its airtightness, which enables greater heating and cooling efficiency, as well as its ability to resist mold and retard fire.
Helping manufacturers to deliver the highest quality cellulose insulation products is C739 on cellulosic fiber thermal insulation. C739 covers the composition and physical requirements of chemically treated, recycled cellulosic fiber loose-fill type thermal insulation for installation in attics or enclosed spaces in housing and other buildings. Insulation product manufacturers also benefit from the use of C1338 on fungi resistance of insulation materials and facings, used to determine the ability of an insulation to support or resist fungal growth under high humidity.
Subcommittee C09.24 on Supplementary Cementitious Materials, part of ASTM Committee C09 on Concrete and Concrete Aggregates, offers standards such as C618 on coal fly ash to enable the reuse of industrial materials in concrete. Similar goals are being achieved by Subcommittee C09.27 on Ground Slag through C989 on slag cement, which specifies reusing ground granulated blast-furnace slag in concrete and mortars.
Better Stormwater Management through ASTM Standards
Another important consideration in sustainable construction is the proper management of stormwater. Impervious surfaces typically found in residential driveways, sidewalks and urban parking lots are susceptible to large amounts of stormwater runoff, which can have harmful environmental impacts: increased pollution and frequent flooding, stream channel instability, concentration of flow on adjacent properties, and damage to transportation and utility infrastructure.
To address these challenges, green building developers are turning to pervious concrete, an environmentally friendly solution for the surfaces of streets, driveways and parking areas that are part of or adjacent to homes and office buildings. Pervious concrete captures stormwater and allows it to seep into the ground, reducing runoff and helping to meet EPA stormwater regulations. By eliminating the runoff of untreated stormwater, pervious concrete advances sustainable development goals by mitigating pollution, protecting streams, watersheds and ecosystems, reducing surface temperatures and heat island effects, and eliminating the need for expensive collection and detention systems. The LEED rating system on high performance, sustainable buildings now recognizes pervious concrete and offers points when it is used for stormwater management in a building project.
ASTM Subcommittee C09.49 on Pervious Concrete is filling the market need for standards for pervious concrete. As a result of its porous nature, pervious concrete cannot be tested using traditional concrete standards. Filling the void is test method C1688 on freshly mixed pervious concrete, which helps verify that the pervious concrete delivered to a project corresponds to the producer's mix proportions, and C1701 on in-place pervious concrete, which is used to detect a reduction of infiltration rate of the pervious concrete, thereby identifying the need for remediation.
ASTM Subcommittee C27.70 on Precast Concrete Products for Stormwater Management, part of Committee C27 on Precast Concrete Products, is also assisting stakeholders, including regulatory agencies and testing laboratories, through test methods and practices aimed at reducing water pollution and controlling erosion. Currently under development by C27.70 is a new testing protocol for stormwater hydrodynamic systems, used to remove settable solids that could cause contamination from stormwater runoff.
Raising the Bar for High Performance Buildings
Today's high performing green buildings share a common characteristic: they do more with less. High performing buildings have small ecological footprints and create a healthy indoor environment for the user; they meet occupants' functional and aesthetic needs while scoring gains in energy efficiency, materials use and sourcing, water efficiency, carbon footprint, construction practices and indoor air quality. Some "net-zero" homes, built on the cutting edge of sustainable development, are so efficient that they generate a large portion of their own energy.
Helping green construction stakeholders to fulfill their vision for high performing homes and buildings is the diverse range of standards from ASTM International Committee E06 on Performance of Buildings. Through 18 technical subcommittees, E06 addresses topics related to the overall performance, improvement, and management of buildings and related facilities. Notable E06 standards that provide valuable utility in sustainable building-related applications include E2634 on flat insulating concrete forms, developed by Subcommittee E06.21 on Serviceability. E2634 focuses on the use of ICF systems as energy efficient building envelopes for both residential and commercial construction.
Airtightness and windtightness are core components in sustainable building design and construction. Controlling air leakage - unwanted flow of air through the external fabric of the building envelope - is central to energy efficiency and unnecessary heat loss. In addition, heat that escapes from buildings carries a significant amount of moisture. This can lead to damage to buildings and building materials, and may have a severe effect on the air quality of the living space. Two E06 standards that assist green building stakeholders in testing and quantifying the airtightness of a building envelope are E779 on air leakage rate and E1827 on airtightness of buildings. To help assess air leakage through the physical parts of the building envelope is another E06 test method, E283 on air leakage through exterior windows, curtain walls and doors. A companion standard, E1105 on water penetration, outlines the procedures for testing the water resistance of installed exterior windows, skylights, doors and curtain walls.
Standards from ASTM Committee E50 on Environmental Assessment, Risk Management and Corrective Action also help with measuring and assessing building performance. Green building owners benefit from E50 standards such as E2797 on building energy performance. E2797 provides a commercially useful practice for conducting an energy performance assessment on a building involved in a commercial real estate transaction and subsequent reporting of the performance information.
High performance green buildings are also defined by their ability to offer high quality indoor air. This result is achieved through ventilation systems that bring in fresh air without losing heat during winter or coolness during summer, control the source of pollutants, and provide predictable and consistent levels of thermal comfort. Air quality in the residential environment is the focus of the efforts of Subcommittee D22.05 on Indoor Air, which is part of Committee D22 on Air Quality. Among D22.05's large portfolio of standards is D6245 on indoor air quality and ventilation. This standard details the use of continuous monitoring of indoor and outdoor carbon dioxide concentrations as a guide for evaluating building ventilation and indoor air quality.
ASTM Standards for Sustainability in Building: Online Compilation
The standards discussed in this overview are included in ASTM Standards for Sustainability in Building, an online compilation of 202 ASTM International standards that address sustainability or aspects of sustainability relative to buildings and construction. This resource is pertinent to almost any green rating system or code that users may come across in the marketplace.Doug Clauson is a freelance writer based in Wynnewood, Pa.
ASTM Resources on Sustainability
ASTM International offers a wide range of informational and other resources for stakeholders involved in various aspects of sustainability and related standards activities.
Sustainability Standards Database - This comprehensive database references over 500 ASTM standards and 300 other standards and programs from other organizations involved in sustainability.
ASTM Standardization News - Articles and other content on sustainability and construction topics are available through two of the online gateways of ASTM's Standardization News magazine. Visitors may also follow relevant news in the field of sustainability through the corresponding Twitter feeds for each of these SN gateways: sustainability and construction.
Purchasing ASTM Standards - More than 13,000 ASTM standards are used worldwide to improve product quality, enhance safety and facilitate trade. You can purchase individual standards; a volume that groups like standards together; a section that is comprised of several volumes covering an industry segment; or the entire collection. Print, CD-ROM and online subscriptions are available. Browse ASTM standards, adjuncts, collections and learn more about purchasing options.
Beyond Standards: Establishing Sustainability with EPDs
Along with the global growth in sustainable building construction has come a rise in "green" product claims from material manufacturers and other industry suppliers. Understanding the meaning and validity of these claims, whether they are based on certification programs or individual company assertions, is becoming increasingly difficult.
To best determine the sustainability of a product, building designers, contractors, consumers and code officials need credible information on environmental impact to make more informed choices. Manufacturers benefit too: not just in the ability to tap into the growing market for green building materials, but through greater awareness of how their products and practices affect the environment. One of the key tools available to help manufacturers assess the true greenness of their products is the environmental product declaration - a detailed report outlining a product's effect on the environment over the course of its lifetime.
In 2012, ASTM International became a program operator for developing product category rules and verifying EPDs in response to the growing need to understand the real environmental impact of products from raw material extraction to disposal and recycling.
PCRs detail the rules and guidelines for developing environmental declarations for products that can fill equivalent functions. EPDs are verified in accordance with the International Organization for Standardization (ISO) 14025 standard to ensure that life cycle assessment data accurately describes the environmental aspects of a product. ASTM technical advisory committees provide specific industry knowledge to the development process for PCRs through ASTM's program in this area.
ASTM International is assisting numerous industries in developing PCRs and verifying new EPDs, making sure that all of the proper procedures are followed. Industry-specific efforts in developing PCRs are currently under way with the following organizations:
- Adhesive and Sealant Council - sealants
- Asphalt Roofing Manufacturers Association - asphalt shingles and bituminous membrane roofing
- Canadian Precast/Prestressed Concrete Institute - precast concrete
- National Concrete Masonry Association - concrete masonry units
- Portland Cement Association - portland cement
- Single Ply Roofing Industry - single ply roofing membranes
- Slag Cement Association - slag cement