Building Codes


Buildings in the Commonwealth account for over half of our state's greenhouse gas emissions - primarily from lighting, heating and cooling. As buildings can last 50-100 years, the way they are constructed has long term impacts on their energy consumption.

Building codes are the regulations that provide minimum requirements for the design, construction, safety, and maintenance of buildings. In this context, energy efficiency minimum requirements are set by a base code. In Massachusetts the base code is established by the Board of Building Regulations and Standards, (BBRS) and modeled on the International Energy Conservation Code. In 2009 Massachusetts became the first state in the nation to adopt a “stretch” energy code for buildings under 100,000 square feet. The stretch code was designed to reduce energy use by 30% and cut carbon emissions 40% compared to buildings built according to the base energy code.  Prior to 2008 any municipality that wanted to adopt a more stringent code had to demonstrate to the BBRS that it was “reasonably necessary because of special circumstances.” However, after passage of the Green Communities Act in 2008, so many cities and towns were expressing interest in the appeals process to adopt more stringent building energy codes that the BBRS voted to create the Stretch Energy Code.

The stretch code supplements the base code by providing a higher standard of energy efficiency, with provisions to meet that requirement.  These provisions include options such as choosing ENERGY STAR qualified insulation, and choosing efficient heating, cooling and lighting.

Stretch Code: A Success Story

The stretch code is widely considered a success story for energy efficiency as over 150 Massachusetts cities and towns have voluntarily adopted it.

According to a MassINC poll of 1,004 Massachusetts residents, 65% strongly support stricter energy efficiency standards for new buildings.

The benefits of energy efficient homes also translate to the real estate market, as energy efficient homes have a higher resale value. Homebuyers recognize they will save money in the long-term through lower utility bills. A survey by the National Association of Home Builders found that “nine out of ten buyers would rather purchase a home with energy-efficiency features and permanently lower utility bills.”

Need For Update

A stretch code only works to conserve energy when it’s actually a “stretch” – i.e. it goes above and beyond the base energy code. And unfortunately the Massachusetts stretch code no longer does so. In 2009 the Mass. stretch code was designed to reduce energy use compared to buildings built according to the 2009 International Energy Conservation Code (IECC), which is a model code adopted by many states, including Massachusetts.

But the IECC is updated regularly, and so as of July 1, 2014, it is no longer the Massachusetts base code. Rather the 2012 IECC is now the Mass. base code, and it is of similar stringency to the Mass stretch code, rendering the term “stretch” inaccurate.

A stakeholder group worked with BBRS to draft an updated stretch code, but it has been in limbo since the adoption of IECC 2012. The BBRS is instead using provisional guidelines and amendments based on IECC 2009.

The delay in implementing a new stretch code has real world implications on communities. For example, to continue to receive incentives under the Green Communities Act, communities now must create their own stretch codes that go beyond the new base code. This will create different stretch codes for every community, causing a huge amount of confusion about energy efficiency standards—a situation that the original stretch code was designed to avoid.

Effectively updating the Massachusetts Stretch Code is an important step in reducing greenhouse gas emissions, as well as improving the infrastructure for future development.


Displacement Prevention in Green Building Policy Fact Sheet

Learn more about Net Zero Buildings

July 2016, Op-Ed, Boston Business Journal, "The Time is Now - We Need To Be Ready<

May 2016 Comments to Board of Building Regulation and Standards (BBRS) re stronger stretch code

November 2015 Letter to Legislature in opposition to S. 1709 (which would eliminate the Stretch Code)Letter of Opposition

October 2015 Letter to Mass. EEA Secretary Matthew Beaton from ten environmental/consumer/building groups calling for stronger stretch code

November 2014 Letter to Governor Patrick calling for updated stretch code

Map of 136 Green Communities

Map of 158 Communities that have adopted the Stretch Code