Energy Efficiency Terms

2012 IECC Code

On July 9th 2013 Massachusetts adopted the 2012 IECC energy code and will go into effect July 1st 2014. This code will be the standard energy code for all of Massachusetts. This code also is approximately 50% better in energy efficiency than existing homes allowing the customer to save on energy costs and create a friendlier green home.

The Town of Mashpee adopted the Stretch Code or appendix 120.AA of The Massachusetts building code in early 2010.  The Stretch Code is an optional part of the Massachusetts Building Code, which increases the energy efficiency requirements for all new construction residential homes.   The BBRS and Department of Energy Resources are deciding whether or not to have a stretch code implemented under the 2012 IECC. If BBRS decides to implement the stretch code this will result in approximately 20% better in energy efficiency than new homes built under the current Massachusetts building code.  We are a Stretch Home Community so if they deem it necessary than Mashpee will have the Stretch Code. (1) Energy and Sustainability Committee

Stretch Code

The HERS Rating was enacted with the addition of the Stretch Code. The HERS rating is an energy audit of a home. The HERS rating is calculated by a set of building plans for the home, which calculate energy loads and consumption. The rating is also calculated by conducting 2 types of tests, which are the blower door test and duct test. After the tests are completed a rating or number is given. The HERS rating is based on a scale of 0 to 100. The lower the score the better or more energy efficient the home is. To comply with the stretch code the maximum number is 70 for homes under 3000 sq ft and 65 for homes greater than 3000 sq. ft. Each point is a 1% decrease in energy consumption.
(2) Home Energy Raters, LLC

HERS Rating

Energy Star

All Appliances are Energy Star rated. These appliances use 10-50% less energy than standard appliances or outdated appliances. These appliances will save you money, energy, and will help reduce emissions of greenhouse gases. Also these appliances are typically better in quality and durability than standard appliances.
(12) Energy Star – Qualified Appliances

The Blower Door Test

The Blower Door Test is performed by The Hers Rater. They test to see the air leakage by depressurizing the home, they do this by taping a big fan to the front door and blows air into the home. This will reveal how tight the home is and if it is insulated properly. The air leakage rate has to be less or equal to 3 air changes per minute the previous code was 7 air changes per minute.
(4) U.S. Department of Energy – Energy Efficiency & Renewable Energy

Air Ducts and Duct Test 

The Air ducts have to be more air tight allowing less air to leak out. All ducts must be completely sealed and insulated with minimum R6 around the basement ductwork and R8 around the attic ductwork. All ductwork has to be hard ductwork. Sealing and insulating the ducts properly can improve the efficiency by 20% The Air ducts are tested by a HERS rater who tests to see the amount of air leakage in the ducts to ensure overall efficiency. The test demonstrates leakage to the outdoors of less than or equal to 3 cfm (cubic feet per minute) per 100 square feet of conditioned floor area and 4 cfm (cubic feet per minute) per 100 square feet of conditioned floor area at post construction.
(5) Energy Star

The furnace has to be 92 AFUE (annual fuel-utilization-efficiency) for gas AND 85 AFUE for other fuels. These furnaces allow for maximum heating comfort while using less energy. High efficiency furnaces are energy star rated and to get that rating furnaces have to be between 90-97 AFUE. These furnaces should save you up to 24% in energy costs.

AC units HVAC System

A/C condensers have to be at least 15 SEER (Seasonal Energy Efficient Ratio). The higher the SEER rating the more energy efficient the unit will be. Or in other words the higher the number the less energy used. The SEER rating is calculated by the total cooling output divided by the electric energy output. Previously the requirement was 13 SEER.
(6) Seasonal Energy Efficiency Ratio 


Light bulbs have to comprise of 80% CFL (Compact Fluorescent Light). CFLs can help you save money, use less energy, reduce light bulb changes, and lower greenhouse gas emissions. These lights will use less power and will last longer than conventional light bulbs. They are also energy star rated. Lighting accounts for about 20% of the electric bill in the average U.S. home. Also any recessed light has to be air tight and IC rated. IC means the light canisters can have direct contact with the insulation. This creates less air leakage and a more energy efficient home.
(7) Mass Save Lighting & Appliances



The insulation requirements are as follows:

R-49 in the ceiling, R- 30 in the floors, R-21 in the walls, and R15/R19 in crawl spaces. Also required for the basement if heated R-15/19 in the walls and the basement slab has to be insulated. The thicker the insulation or higher the R value the greater the thermal resistance is. Also a continuous air barrier (usually plywood) must be installed around the building envelope from a conditioned to an unconditioned space to help reduce on air infiltration. (“The higher the R-value, the greater the insulating power”The Federal Trade Commission)
(9) Home Insulation

Insulated Headers

Insulated Headers are any exterior header whether it is for a door or window; they can be insulated with rigid foam board or any other acceptable insulation R value. Insulated headers reduce heat loss and are more energy efficient. This is an upgrade to any pre existing home not built under the stretch code or 2012 IECC.


The u factor for windows is u-32. The U- factor is the rate of heat loss. The lower the u factor the better the insulating power. The previous requirement was u-35.
(10) Energy Star – 
Independently Tested and Certified Energy Performance

Kassen Keller Windows Modernview

The Kassen Keller windows are a high efficiency design. These types of windows have a very low u-value and a low carbon footprint. These widows have low energy consumption helping you reduce on energy costs up to 20%.
(13) EcoShield Window Systems

Water Heater

Energy Efficiency descriptions.

Bathroom Ventilation Fans

Energy star bathroom fans have to be installed under the 2012 IECC code in every bathroom. These fans are more energy efficient and make less noise. Also these fans will allow proper ventilation, which will improve the indoor air quality. These fans will turn on every so often to send the air outside.
(11) Ventilation Fans

Tight Construction-2x6 Construction

2 x 6 construction allows you to increase the thickness of the insulation and getting an R-21 value in the walls creating a much more energy efficient home. 2x6 construction also minimizes voids in the insulation leading to a much tighter home. It also will create a much sturdier and well sound product.

Open Floor Plans and Central Air

The open floor concept will create better air quality and ventilation. Also they allow for more efficient heating and cooling throughout the home. Our designs will allow more natural light into the home as well.


The fireplace wall (Ceiling) now has to have insulation and an air barrier installed prior to the installation of the fireplace. Gas is much more energy efficient the conventional wood burning fireplaces. They also release fewer emissions.