Some contractors in Maine were caught off guard when new efficiency codes based on 2015 International Energy Conservation Code (IECC) regulations went into effect on July 1. Even before new efficiency standards were enacted in 2009, Katahdin Cedar Log Homes has been at the forefront of meeting and exceeding efficiency requirements because of our long-term commitment to the environment. Our insulation package debuted in the late 1970s and we’ve consistently updated and improved it to be the Energy Envelope System available in all our log homes today.

Energy Envelope System
Katahdin’s Energy Envelope System offers flexibility to meet insulation code requirements.

We dived deeper to determine what has changed in the Maine Uniform Building Energy Code and how that will be implemented in your log home in the future.

Increasing R-value Requirements for Walls and Roof Structures
Based on IECC 2009 codes, R-20 was the required level of insulation for exterior walls in new residential construction up to this point. The R-value is based on a material’s ability to resist heat transfer or flow from one side to the other. A higher R-value number, the better the insulation is.

The new regulations in effect July 1, 2021 in Maine require a minimum of R-25 in walls for all municipalities. Some cities, including Portland and South Portland, have opted for so-called “stretch” regulations which aligns with more stringent IECC 2021 codes adopted this year. That boosts the wall insulation requirement to R-30.

Despite an efficiency code exemption carve-out in many states for log homes in 2009, Katahdin has had no problems implementing insulation requirements. In fact, our flexibility combined with a whole log wall construction puts us in a unique position within the log home industry.

Focus on Air Sealing
In addition to insulation, air sealing works hand-in-hand with insulation to keep homes efficient. In 2009 IECC codes, the rate of air exchanges per hour (aeh) topped out at 7 aeh. These air exchange rates are measured using a blower door test, a diagnostic tool that measure air leakage by lowering indoor air pressure. An auditor then reviews areas in the home with a UV infrared camera to pinpoint where air is leaking in. Once these tiny gaps and cracks are sealed, the insulation can perform as designed. We covered a new technique last month that uses a blower door test to apply air sealant in one step that may be particularly useful in this instance.

The new 2015 IECC regulations cuts the air exchanges to under 3 aeh, which also requires that additional mechanical ventilation be included in the design. Most times this is achieved with heat recovery ventilation (HRV) or energy recovery ventilation (ERV) connected to the HVAC systems. These enhanced ventilation systems maintain great indoor air quality along with keeping energy costs down.

NH LEED Katahdin Log HOme
Platinum LEED Arborwall Home in NH helped to refine air sealing and efficiency techniques in Katahdin Cedar Log Homes.

What Does This Mean for Katahdin Cedar Log Homes?
Although some conventional Maine builders are scrambling to meet these new requirements, Katahdin Cedar Log Homes and Arborwall Solid Cedar Homes rely on our established building systems and construction techniques to reach any desired efficiency as well as meeting energy codes. Our Energy Envelope System is designed to be flexible to meet increases in wall and ceiling insulation R-values—at or beyond code requirements. Air sealing techniques have been developed as well in Katahdin homes through the construction of Platinum LEED and other high-efficiency homes that require excellent air sealing.

For Those Planning to Build Outside of Maine
The 2015 and 2021 IECC standards are being adopted on a state-by-state and town-by-town basis. That’s why it’s a great idea to check in with the code enforcement officer where your land is located to ensure you understand which standards for insulation and air sealing will be required. Once you learn the requirements, make sure your dealer or the planning department at Katahdin Cedar Log Homes has the details to incorporate it into your plans.