Building Energy Code Overview

Decisions to select a particular window are often strongly influenced by mandatory building energy codes or voluntary government and utility energy-efficiency programs. In states and localities that have adopted building energy codes, these codes typically set a minimum level of window thermal or home energy performance to which the builder, remodeling or replacement window contractor, or homeowner must adhere. As a result, the responsible decision-maker (builder, contractor or homeowner) should start the window selection process by first consulting building code requirements, since these requirements generally set the legal minimum level of energy efficiency that must be achieved. Voluntary programs, offered by both utilities and government agencies, provide homeowners and builders with complementary information about efficiency performance, direct or indirect financial incentives, or marketing support, all of which are intended to drive the market towards the selection of more efficient windows.

State and Local Adoption of Building Energy Codes
Building codes today typically have an energy efficiency/conservation code subset intended to guarantee that a minimum level of cost-effective, energy-efficient technologies are part of the design package. These energy code requirements typically establish minimum threshold specifications or characteristics for buildings and their component products, whether they are windows, wall insulation, or other building components. Up-to-date codes that are clear and easy to enforce can be especially effective at ensuring energy efficiency and maximizing occupant comfort.

Building energy codes are adopted at a state or local level. With a few notable exceptions, most jurisdictions do not develop their own energy codes from scratch. Instead, they rely on adopting uniform model energy codes developed by national code writing entities, occasionally tailoring or amending these codes to suit the particular needs of their jurisdiction.

2006 IECC: A Simpler Approach to Building Energy Codes
The 2006 IECC represents the next stage in the evolution of model energy codes in general and window requirements specifically. This version is based on the important concept that simplified, easy-to-understand requirements will lead to more/better code adoption, compliance and enforcement. The 2006 IECC is far shorter and less complex than previous versions.

The 2006 IECC establishes only 8 climate zones nationwide and assigns each county to a single zone. It establishes a single prescriptive compliance path for all building envelope components, including specific U-factor maximums for fenestration (with separate requirements for skylights) and SHGC maximums for all glazed fenestration.

Building Energy Code Overview | State Code Factsheets | Code Links