BECx, LCAs, PCRs and zEPI

New sustainability terms and concepts will affect roofing projects

As the sustainability movement grows, construction projects are becoming more complex. An unfortunate reality of this complexity is the documentation required to demonstrate compliance with various requirements common to projects with sustainable and/or high-performance goals. Voluntary points-based programs such as Green Globes,® LEED® and RoofPoint™ have terms and concepts that may be foreign to many in the construction industry—especially those working on one of these project types for the first time.

In addition, the most recent codes and standards, such as the International Energy Conservation Code® (IECC), International Green Construction Code (IgCC), 2012 Edition, ASHRAE 90.1-2010, "Energy Standard for Buildings Except Low-Rise Residential Buildings," and ASHRAE 189.1-2011, "Standard for the Design of High-Performance Green Buildings," also often contain unfamiliar terms and concepts.

To assist you when working within this new framework, following are some sustainable terms and concepts with which you should become familiar, as well as an explanation why they may be encountered.

Environmental product declaration

An environmental product declaration (EPD) is a document related to a product or service that provides quantified environmental data based on the International Organization for Standardization's (ISO's) standard 14040, "Environmental management—Life cycle assessment—Principles and framework."

EPDs can be used to evaluate the environmental impact of a product or service during its life cycle, as well as the raw materials and manufacturing methods used and disposal effect at the end of its service life. The effects of transportation, maintenance, repair and waste processing, as well as the suitability for reuse, recycle or recovery also may be considered.

EPDs are developed according to product category rules (PCRs). The idea is for products to be evaluated according to a common PCR so information in EPDs for similar products will be comparable. For the construction industry, there is a PCR Basic Module, "Construction products and (CPC Division 54) construction services for buildings and other construction works," produced by the Swedish Environmental Management Council (SEMCo). The document's intent is to provide PCRs for assessing environmental performance of construction products and services and the performance declaration by an EPD. The document also can be used to create supplementary PCRs for specific types or classes of construction products.

You may want to become familiar with EPDs because construction specifications could require using roofing products with EPD documentation. Also, LEED v4 (version 4), which was approved by the U.S. Green Building Council's (USGBC's) membership in July, has a building product disclosure and optimization credit that requires using products with EPDs. Other programs, sustainable-minded architects and owners may insist on using products with EPDs, as well.

There are a number of organizations serving as program operators for the EPD system. ISO defines a program operator as an independent entity that oversees development of PCRs and EPDs according to a set of published general program instructions that regulate basic processes and procedures.

In addition to SEMCo, NSF International (NSF®), formerly known as the National Sanitation Foundation, develops PCRs and provides EPD verification services. NSF has a multistakeholder committee to develop an American National Standard to assess the sustainable attributes of single-ply roof membranes. The standard, NSF/ANSI 347, "Sustainability Assessment for Single Ply Roofing Membranes," was published in May 2012.

Another program operator is ASTM International. ASTM International has a four-step EPD process that includes developing a PCR; conducting a life cycle assessment to determine environmental impact across a product's life span (development, use and disposal); developing an EPD; and verifying the EPD.

Also serving as program operators are ICC-Evaluation Service LLC, which has an EPD development process similar to ASTM, and Underwriters Laboratories LLC, which develops EPDs and PCRs.

Currently, there are few roofing-related products with EPD documentation. As LEED v4 projects become more prevalent, I expect the number of manufacturers seeking EPDs to increase.

Life cycle assessment

The holistic approach used for EPDs is known as life cycle assessment (LCA). LCA is an approach for assessing industrial systems during an entire life cycle. The life cycle sometimes is called "cradle to grave," where a product or service is evaluated from its manufacture, including the raw material and acquisition processes required to create the product or service, use, maintenance and final disposal. When a product or service is evaluated from resource extraction to production but before consumer use, the partial LCA is known as "cradle to gate."

The LCA process to assess the environmental aspects and potential effects associated with a product, process or service is described in three steps by the U.S. Environmental Protection Agency's (EPA's) National Risk Management Research Laboratory:

  1. Compile an inventory of relevant energy, material inputs and environmental releases
  2. Evaluate the potential environmental impacts associated with identified inputs and releases
  3. Interpret the results to make an informed decision

When discussing roofing options with a sustainable-minded owner, it is useful to have a basic understanding of LCA and why a particular roof system may appear different (environmentally speaking) when comparing its life cycle performance versus its energy requirements for a particular stage of its life.

For example, a recyclable system that requires more energy to produce and install still may be a better environmental solution than a system that requires less energy to produce and install but is not recyclable. Life cycle principles also illuminate why products produced near a project location are more desirable than products obtained from afar because the energy needed and the pollution produced during transport would be much less for the locally obtained product.

Building enclosure commissioning

Building enclosure commissioning (BECx) is when a building envelope's design, which includes the roof system, and installation are evaluated independent of the project team. The entity responsible for conducting the commissioning is known as the building enclosure commissioning agent (BECxA). The BECxA may make site inspections independently of the project roof consultant or architect and may conduct performance testing to evaluate the performance and durability of enclosure materials, components, systems and assemblies.

Typically, this occurs on high-profile projects or when required as part of a high-performance building program. Also, LEED v4 requires basic BECx for new construction projects as a prerequisite for LEED certification. LEED points can be earned for more intensive BECx for new construction or for using BECx as part of an applicable existing building LEED v4 project.

There are three significant documents relating to BECx:

  • ASHRAE Guideline 0–2005: The Commissioning Process
  • National Institute of Building Sciences (NIBS) Guideline 3-2012: Building Enclosure Commissioning Process
  • ASTM E2813-12, "Standard Practice for Building Enclosure Commissioning"

For projects with BECx requirements, roofing contractors need to interact with BECxAs and project teams. You may be required to provide specific submittals to the BECxA or provide or facilitate access to the work areas. If BECxA-specific submittals are not required, a longer submittal review time generally will be needed so the BECxA can review project submittals and provide comments.


Benchmarking is the tracking of energy use by a building or facility over time and comparing it with similar buildings or facilities. This information can help determine the effectiveness of energy-efficiency upgrades such as adding more thermal insulation or improving air-barrier performance. For benchmarking to be effective, data from similar buildings or facilities must be available for comparison.

The EPA has a popular, free online benchmarking tool called ENERGY STAR® Portfolio Manager.® Within the application is a benchmarking starter kit that requires basic data such as square footage, building use, energy source type used and input of a minimum of 12 amounts of energy data typically obtained from utility bill statements. Many building types (mostly nonresidential) can be evaluated using the program.

Although benchmarking likely will not affect you directly, an understanding of the process can help you discuss the potential energy savings that may be realized by a client when considering roof system options. If a facility is tracking benchmarking energy data before installing a new roof system, there could be expectations of energy savings as a result of the newly installed system. You may want to work closely with the roof system manufacturer and client's design professional to ensure expectations for energy savings remain realistic. Also, realizing how factors other than the roof system can affect energy efficiency may be important depending on a particular project's scope.

Net-zero energy building

There are several definitions for net-zero energy building (NZEB). One of the most common is a building that consumes no more energy in a year than it can produce via on-site renewable energy while creating zero carbon emissions. Few existing buildings meet this definition, but NZEB is considered to be one of the ultimate goals in the sustainability movement.

Executive Order 13514, "Federal Leadership in Environmental, Energy and Economic Performance," signed in October 2009 by President Obama requires federal buildings designed beginning in 2020 to achieve net-zero energy by 2030. The Department of Energy also has targeted 2020 as the year marketable residential NZEB should be available; 2025 is the target year for commercial buildings.

IgCC 2012, Section 602, "Modeled Performance Pathway Requirements," incorporates the idea of NZEB into I-Codes by inclusion of the Zero Energy Performance Index (zEPI). A zEPI score of zero represents a building with net-zero energy use when evaluated by predictive performance-based modeling. A zEPI score of 100 represents the average energy used by a building in the year 2000. IgCC 2012 is based on a maximum zEPI score of 51 though a jurisdiction that adopts IgCC 2012 is free to adjust the required zEPI score higher or lower.

NZEB and zEPI may be of interest to you because roof system components contribute to a zEPI score. A highly energy-efficient roof system is necessary to achieve a low zEPI score and, ultimately, NZEB. Also, systems such as rooftop photovoltaic (PV) systems are a potential NZEB component because they are an on-site renewable energy source and PV systems do not produce carbon emissions.

Final thoughts

The terms and concepts discussed in this article are just a few of the many that will affect the roofing industry in the coming years. As the market adjusts to the various sustainable-based requirements and consumers become more sensitive to environmental issues, having a solid understanding of these issues will assist you with managing a thriving business. Our industry always has adjusted well to changing times and emerged stronger for it.

JASON WILEN, AIA, CDT, RRO, is an NRCA director of technical services.

Did You know?


Daylighting is using natural light within a building or space to reduce the need for powered lighting to save energy. Although a daylighting system is not directly related to roof system installation, often skylights are used as part of a daylighting system. To be considered a daylighting system, a control system is used to sense ambient lighting within a space and automatically reduce or turn off powered lighting systems when natural light sources are providing a desired light level. Shading systems often are used to control direct light on task surfaces, such as desks or tabletops, or to reduce glare.

International Energy Conservation Code® (IECC) 2012, Section C402.3.2 contains mandatory requirements for using daylighting in some situations. For example, when working with skylights, designers and roofing contractors should be aware the energy code contains minimum performance requirements. If skylights are part of a daylighting system, additional requirements for integration into a control system may apply per IECC 2012, Section C402.3.2.1.

NRCA's Guidelines for Complying With Energy Code Requirements for Roof Assemblies: International Energy Conservation Code, 2009 and 2012 Editions lists the code requirements for skylights and daylighting. NRCA also maintains a database of energy codes by state. Both are available on NRCA's website at



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