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Related Covered Product Categories
The Federal Energy Management Program (FEMP) provides acquisition guidance for cool roof products, a product category covered by ENERGY STAR efficiency requirements. Federal laws and requirements mandate that agencies purchase ENERGY STAR-qualified products or FEMP-designated products in all product categories covered by these programs and in any acquisition actions that are not specifically exempted by law.
FEMP's acquisition guidance and associated ENERGY STAR efficiency requirements for cool roof products are technology neutral, meaning that one technology is not favored over another. However, ENERGY STAR's product specification requirements are limited to cool roof products tested through the Cool Roof Rating Council (CRRC) Product Rating Program, including Color Family Groups and Compound Product Ratings, or evaluated using the test methods for ENERGY STAR qualifications listed in the ENERGY STAR product specification information.
All other roof products are excluded, including but not limited to roof products intended for use on siding or walls.
This acquisition guidance was updated in December 2021.
Find Product Efficiency Requirements
The U.S. Environmental Protection Agency (EPA) provides cool roof product efficiency levels and product specification information on its ENERGY STAR website. Manufacturers meeting these requirements are allowed to display the ENERGY STAR label on complying models.
Make a Cost-Effective Purchase: Save $0.64/ft2 or More by Buying Energy Star
FEMP has calculated that the required ENERGY STAR-qualified cool roof product saves money if priced no more than $0.64/ft2 (in 2020 dollars) above the less efficient model (e.g., $640 for a building with a 1,000 ft2 roof). The best available model saves up to $1.11/ft2 (e.g., $1,110 for a building with a 1,000 ft2 roof). Table 1 compares three types of product purchases and calculates the lifetime cost savings of purchasing efficient models. The savings for each location depend on the magnitude of the heating and cooling loads.
|Table 1. Lifetime Savings for Efficient Cool Roof Products|
|Performance||Best Available||ENERGY STAR||Less Efficient|
|Solar Reflectance after 3 Years||0.87||0.5||0.05|
|Annual Energy Savings (kWh/ft2)||1.78||1.03||======|
|Annual Energy Cost Savings ($/ft2)||$0.06||$0.04||======|
|Lifetime Energy Cost Savings ($/ft2)||$1.11||$0.64||======|
View the Performance and Model Assumptions for Table 1
Solar Reflectance after 3 Years: The fraction of total solar energy that is reflected away by a surface 3 years after installation, based on typical values and ENERGY STAR values.
Annual Energy Savings: A measure of the net energy savings from a reduction in cooling load and increase in heating load, listed in kWh/ft2. Based on the effect of changes in solar reflectance on reported heating and cooling values from the Synnefa et al. 2007 journal article, Estimating the effect of using cool coatings on energy loads and thermal comfort in residential buildings in various climatic conditions (Energy and Buildings, 39 (2007) 1167-1174) for Miami, New York City, and Los Angeles, listed in kWh/ft2.
Annual Energy Cost Savings: For cooling, calculated based on an assumed electricity price of $0.09/kWh, which is the average electricity price at federal facilities, listed in $/ft2. For heating, calculated based on an assumed natural gas price of $0.56/therm, which is the average natural gas price at federal facilities, listed in $/ft2. Learn more about Federal Government Energy/Water Use and Emissions.
Lifetime Energy Cost Savings: Calculated as the sum of the discounted value of the annual energy cost over the assumed product life of 30 years, listed in $/ft2. Future electricity and natural gas price trends and a 3% discount rate are from Energy Price Indices and Discount Factors for Life-Cycle Cost Analysis–2021: Annual Supplement to NIST Handbook 135 (NISTIR 85-3273-36).
Best Available Model Column
Calculated based on the December 2021 ENERGY STAR List of Qualified Products; values shown are rounded to the nearest dollar. More efficient models may be introduced to the market after FEMP's acquisition guidance is posted.
Energy Star Model Column
Calculated based on December 2021 ENERGY STAR efficiency levels; values shown are rounded to the nearest dollar. Federal agencies must purchase products that meet or exceed ENERGY STAR efficiency levels.
Less Efficient Model Column
Calculated based on a typical black roof.
Determine When ENERGY STAR Products Are Cost-Effective
An efficient product is cost-effective when the lifetime energy savings (from avoided energy costs over the life of the product, discounted to present value) exceed the additional up-front cost (if any) compared to a less efficient option. ENERGY STAR considers up-front costs and lifetime energy savings when setting required efficiency levels. Federal purchasers can assume ENERGY STAR-qualified products and products that meet FEMP-designated efficiency requirements are life cycle cost-effective. In high-use applications or when energy rates are above the federal average, purchasers may save more if they specify products that exceed federal efficiency requirements (e.g., the best available model).
Claim an Exception to Federal Purchasing Requirements
Products meeting ENERGY STAR or FEMP-designated efficiency requirements may not be life cycle cost-effective in certain low-use applications or in locations with very low rates for electricity or natural gas. However, for most applications, purchasers will find that energy-efficient products have the lowest life cycle cost.
Agencies may claim an exception to federal purchasing requirements through a written finding that no FEMP-designated or ENERGY STAR-qualified product is available to meet functional requirements, or that no such product is life cycle cost-effective for the specific application. Learn more about federal product purchasing requirements.
Incorporate Federal Acquisition Regulation Language in Contracts
These mandatory requirements apply to all forms of procurement, including construction guide and project specifications; renovation, repair, energy service, and operation and maintenance (O&M) contracts; lease agreements; acquisitions made using purchase cards; and solicitations for offers. Federal Acquisition Regulation (FAR) Part 23.206 requires agencies to insert the clause at FAR section 52.223-15 into contracts and solicitations that deliver, acquire, furnish, or specify energy-consuming products for use in federal government facilities. To comply with FAR requirements, FEMP recommends that agencies incorporate efficiency requirements into technical specifications, the evaluation criteria of solicitations, and the evaluations of solicitation responses.
Find Federal Supply Sources
The federal supply sources for energy-efficient products are the General Services Administration (GSA) and the Defense Logistics Agency (DLA). GSA sells products through its Multiple Awards Schedules program and online shopping network, GSA Advantage!. DLA offers products through the Defense Supply Center Philadelphia and online through FedMall (formerly DOD EMALL). Products sold through DLA are codified with a 13-digit National Stock Number (NSN) and, in some cases, a two-letter Environmental Attribute Code (ENAC). The ENAC identifies items that have positive environmental characteristics and meet standards set by an approved third party, such as FEMP and ENERGY STAR.
The United Nations Standard Products and Services Code (UNSPSC) is a worldwide classification system for e-commerce. It contains more than 50,000 commodities, including many used in the federal sector, each with a unique eight-digit, four-level identification code. Manufacturers and vendors are beginning to adopt the UNSPSC classification convention and electronic procurement systems are beginning to include UNSPSC tracking in their software packages. UNSPSCs can help the federal acquisition community identify product categories covered by sustainable acquisition requirements, track purchases of products within those categories, and report on progress toward meeting sustainable acquisition goals. FEMP has developed a table of ENERGY STAR and FEMP-designated covered product categories and related UNSPSC numbers.
Cool Roof Product Schedules and Product Codes
The DLA ENAC for cool roof product models is "EC".
The UNSPSCs for cool roof products are listed in Table 2.
|Table 2. Product Codes for Cool Roof Products|
|Cool Roof Product Type||UNSPSC|
|Concrete Roofing Tile||30151511|
|Brick Roofing Tile||30151512|
|Ceramic Roofing Tile||30151513|
|Metal Roofing Tile||30151514|
Buyer Tips: Make Informed Product Purchases
The three properties to look for when selecting a roof material to reduce building cooling load are:
- High solar reflectance
- Endurance of high reflectance over time
- High emittance.
The ENERGY STAR program presently considers reflectance only, not emittance. High emittance lowers roof temperature by increasing the release of heat by thermal radiation. To ensure a high-emittance roof, avoid unpainted metal roofs and aluminum coatings. If installing a metal roof, make sure it is painted a light color (not with a clear coating).
When deciding whether to install a cool roof, you'll need to determine whether the cost will justify the energy savings. How much energy you will save depends on several factors such as your home's climate and environment, how well insulated your current roof is, the type of roof you have, and the efficiency of your heating and cooling system.
Your climate is an important consideration when deciding whether to install a cool roof. Cool roofs achieve the greatest cooling savings in hot climates, but can increase energy costs in colder climates due to reduced beneficial wintertime heat gains.
Some utilities offer rebates or other incentives for the purchase of ENERGY STAR-qualified products. Use the ENERGY STAR Rebate Finder to see if your local utility offers these incentives.
User Tips: Use Products More Efficiently
Choose an installer carefully to ensure proper installation of a roof product or roof coating that will maximize durability and solar reflectance. The National Roofing Contractors Association (NRCA) provides some helpful advice in its guidelines for selecting a roofing contractor. Roofs should be properly examined at regular intervals and maintained or cleaned when necessary and appropriate to assure the maximum solar reflectance.
Lawrence Berkeley National Laboratory provided supporting analysis for this acquisition guidance.