The International Energy Conservation Code (IECC) constantly evolves to meet current energy efficiency needs. Over the years new requirements have been added to the IECC to make it stricter and increase overall energy efficiency of buildings. Some states are resistant to these changes, and some choose not to adopt an IECC at all. In fact, of the 50 states and the District of Columbia, 10 either haven’t adopted an IECC, or are operating under a code older than the 2006 IECC, according to the Online Code Environment and Advocacy Network.

However, the majority of the 50 states have embraced the energy codes and are slowly, but surely, updating the energy related portions of their statewide building code. As of July Vermont and Maryland have already adopted the 2015 IECC and implemented the updates into their building code.

In addition, 11 states are currently operating under the 2012 IECC; 22 are operating under the 2009 IECC; six are operating under the 2006 IECC; and as previously mentioned, 10 either haven’t adopted an IECC or are operating under a code older than the 2006 IECC.

So, what does the new 2015 IECC mean for contractors? In terms of airtightness testing, little has changed from the 2012 to the 2015 IECC. Building envelope testing requires air leakage rates of less than five Air Changes per Hour (ACH) in climate zones 1 and 2, and 3 ACH in zones 3 through 8. Duct leakage testing requires air leakage rates of less than four cubic feet per minute per 100 square foot of conditioned floor area.

However, there are a couple of noteworthy updates, such as an industry-wide standard for blower door tests and the introduction of an Energy Rating Index, which helps homebuyers make informed purchases. Here is what you need to know about each:

Blower Door Test Standards

The first big change is a defined standard for blower door testing, which ensures accurate and repeatable tests. The 2015 IECC cites two formal test standards: ASTM E779 and ASTM 1827.

The ASTM E779 test standard includes directions such as:
--Test at a minimum of five data points between 10 and 60 Pascals (Pa), in increments between 5 and 10 Pa.
--Complete a pressurization and depressurization test.
--Under this standard, there are limitations on the conditions in which the test can be performed. These limitations are based on the difference between indoor and outdoor temperatures and the height of the building.

The ASTM 1827 test standard includes directions such as:
--Choosing between a repeated single-point and a repeated two-point test.
--Single-point is tested at 50 Pa, with a baseline before and after, and is repeated five times.
--Two-point is tested at 50 Pa and 12.5 Pa, with a baseline before and after, and is repeated five times.
--Testers can choose to pressurize, depressurize or both.

These standards are a welcome update to the IECC. Requiring that testing is done to a specific standard not only helps ensure that the test is performed correctly, but also that it is accurate and repeatable. While there were test requirements for air leakage testing of the building envelope in the 2009 and 2012 IECC, neither referenced a formal test standard. The 2015 code requires contractors to follow one of the above ASTM test standards.