Construction Industry: Building to Energy Code

Builders and designers within the construction industry have a direct affect on U.S. energy consumption with the buildings they produce. For this reason, striving for energy efficiency and code compliance are vital aspects of operating a construction business. By constructing and designing buildings to code, designers and builders not only create buildings and renovations that conserve energy, but also provide consumers savings on their heating and cooling expenses.

The Department of Energy regulates energy codes and compliance requirements. Businesses within the construction and building industries work in tandem with The Department of Energy (DOE), and their Building Energy Codes Program (BECP) in order to make building practices and technologies more efficient.

Energy Code Compliance Methods

Energy code compliance is required for all building types. For residential structures, builders and designers must take energy conversation measures into consideration for items including: air leakage, vapor retardants, service water heating, duct installation and construction, temperature controls, and on/off controls for swimming pools, where applicable.

Although commercial builders and designers must comply with energy code conservation regulations, building system components are generally evaluated on a larger scale. For example, builders and designers within commercial building consider conservation methods for the following components: envelope or overall building structure, lighting, and mechanical systems.

When building, construction businesses choose an approach to utilize in order to comply with energy code requirements. Currently, there are three approach methods available. The approaches take into account levels of energy consumption, based on R-values, and U-factors. R-values measure thermal resistance, and U-factors measure the rate of heat loss. As regulated by the DOE, the three approaches are as follows:

1. Prescriptive Approach: With the prescriptive approach, users obtain lists of the minimum R-value or maximum U-factor requirements for each building component, such as for windows, walls, and roofs based on “climate zone” location. Although this approach is relatively simple to use, there are restrictions: it utilizes requirements that are based on worst-case assumptions, and requirements must be met exactly as specified.
2. Trade-off Approach: With this approach, users can “trade” energy efficiencies in building components so that components that exceed requirements can compensate for those that do not meet code. For example, a builder may “trade” low wall insulation efficiency measures with high window efficiency measures so that both components are within code.
3. Performance Approach: With this approach, users must obtain an annual energy analysis first, and compare their proposed building against a baseline design. For builders or designers utilizing special energy maximizing features, such as solar panels or thermal energy storage, this approach is required. Although this method does provide greater flexibility, it requires significantly more effort than the other two approaches.