Strategic Electrification Initiative

Spring is finally here and construction is picking up fast! We hope you find this update useful and informative.

Air Tight Insight is a publication of Ace Energy Services, Inc. (a HERS Rating and energy code certification services company) and 3ACH50 Inc. (specializing in cost-effective, results-driven air sealing) are proud to be the go-to resource providing you with relevant, easy-to-understand information on energy code(s), building science and green building standards in the Commonwealth.

Feel free to contact us with any questions, comments, or suggestions at Tim@AceEnergyMA.com

MA Code Update

Slab Edge Insulation per MA code is R10, which is typically 2-inches of high-density foam board extending either 2 feet down vertically or 2 feet under horizontally.

It applies to slabs that are within one foot of grade. The reason for this topic this month is to stress that it should be done always for walk-out basements even when the basement is unconditioned. Slab edge insulation is necessary for homeowners that have the option to make a conditioned basement.

Often, it is necessary to include the basement as conditioned space to pass a HERS 55. The main reasons are it brings duct systems inside conditioned space and adds volume for the building air exchange rate as measured by the blower door.

Many builders have found low cost ways to make a conditioned basement for energy efficiency purposes. We must have 1) insulated walls (does not have to meet prescriptive R19/R15), 2) a heat supply and return, 3) properly sized heating and cooling equipment, and slab edge insulation if a walk out exists.

From the Field – Bonus Room Walls & Building Air Tightness

The picture below shows the exterior side of a wall that is partially over a garage and has three walls with poly on the back side. The poly will increase air leakage significantly when blower door testing is done and may mean the difference in passing HERS 55. Poly is very difficult to sealed effectively.

A rigid air barrier that is sealed on the backside of these walls will make these walls a much more effective air barrier and help achieve a passing air change rate required by code.

Green Building – Strategic Electrification Initiative

Northeast Energy Efficiency Partnerships (NEEP) has recently published an “Action Plan to Accelerate Strategic Electrification in the Northeast”. In recent years, Northeast states have made significant progress developing two of four central strategies included in the plan. These are increasing energy efficiency and the installation of renewables.

Certainly, we (HERS Raters and builders) have seen energy codes for new home construction increase efficiency significantly and on a broad scale in recent years. Solar systems on existing homes can be seen everywhere.

Powering end uses such as in heating homes with heat pumps and driving cars with electricity instead of fossil fuels in a way that increases energy efficiency and reduces pollution. It lowers costs to consumers and society and is necessary to meet state goals of reducing carbon emissions of 80% by 2050.

Fortunately working towards these goals helps drive economic development as we move away from fossil fuels to more sustainable energy future.