The following post was provided by DiMella Shaffer.


Four heads are better than one.

On December 23rd, 2022, the clock started ticking for the architectural community when the DOER released a final version of the updated Massachusetts Stretch Code and the new Specialized Opt-in Code. Knowing that the changes would be significant, various taskforces were created by Alison Nash of Sasaki. A “Decision Tree” taskforce was established in January, and includes Sustainable Design Leaders, Gabrielle Aitcheson of ICON, Suni Dillard of HMFH, Lauren Gunther of DiMella Shaffer, and DiAnn Tufts of PCA.

The Sustainable Design Leaders is a national peer network group through BuildingGreen, which facilitates connections amongst the most passionate sustainability advocates. Given that each of our offices has expertise in various project types, we were able to bring different perspectives to the table. Over the course of five months, the group dissected the new energy code language, and each leader took on mapping the trees and branches of each compliance path, while also providing QAQC. Additionally, review comments were incorporated from the greater Architecture, Engineering, & Construction (AEC) community.

The result of our analysis is the creation of (2) decision trees and (8) decision tree branches.

MAIN DECISION TREE: New Construction

New Construction Branches:
» Small Residential, less than 12,000 SF
» Low-Rise Multifamily, greater than 12,000 SF
» Mid + High-Rise Commercial Multifamily
» Small Commercial, less than 20,000 SF
» Large Commercial, Low Ventilation
» Large Commercial, High Ventilation

MAIN DECISION TREE: Existing Construction

Existing Branches:
» Existing Low-Rise Residential
» Existing Commercial + Multifamily

Decision Trees + Branches

Changing systems need a roadmap.

Below is an outline of the overall concept, how to navigate the decision trees, and what to pay attention to.

Here’s what the decision trees do:

• Broadly show the difference between the Base Energy Code, Stretch Code, and the Specialized Opt-in Code.
• Act as a quick reference to identify key decisions and options for paths to compliance.
• Reference code sections related to each path.
• Provide “fun facts” to help guide the process.

Here’s what the decision trees do not do:

• Do not explain what is in each referenced code section.
• Do not provide every referenced code section.
• Do not provide definitions for all terms used through the paths.
• Do not include other codes or ordinances.
• Do not guarantee alignment with the Authorities Having Jurisdiction (code officials).

How the decision trees work:

• Start with the New Construction or Existing construction decision trees and answer the questions to determine which branch to follow.
• Use the branch to determine the appropriate path or path options for your project.
• The identified path is the starting point to communicate with all those involved in the project and confirm interpretation with code officials.

What to pay attention to:

• Know what Code is being used by the municipality; refer to map blog post.
• One “Use” and/or “Existing Building Scope” at a time.
• Cross reference with the “Municipal Fossil Fuel Free Building Demonstration Program” and other relevant ordinances.
• All optional pathways are indicated even if the pathway would not be typically used.
• Our focus is on understanding the intent of the code, not a specific interpretation.
• All buildings in MA Stretch Code communities, including buildings under 100,000 square feet, are required to follow the Stretch Code. This also includes existing • and low-rise residential buildings.
• The decision trees and branches are for educational purposes. *
• Updates will occur from time to time, but the link will remain the same. Note the version date in the file name and on individual pages.


We need to learn to crawl before we can walk.

We approached the decision trees and branches as foundational. The ability to provide graphically, easy to understand diagrams for design teams, clients, contractors, and code officials has been paramount for effectively communicating complex (and ground-breaking) energy codes.

Our goal is to continue outreach to the greater community. The “COTE: DOER Critical Stretch Code Series”, led by Alison Nash and Lara Pfadt provides incredibly insightful presentations from various experts in the field, and this past March, Suni Dillard and I presented the existing construction decision trees and branches to the BSA/Committee on the Environment (COTE) community.

Post contributors include Gabrielle Aitcheson of ICON, Suni Dillard of HMFH, Lauren Gunther of DiMella Shaffer, and DiAnn Tufts of PCA. Please reach out to any of us if you would like to learn more about the decision trees.

We aim for the community to spend less time understanding the changes, and more time applying the energy code. The information contained herein is for educational purposes only but does not guarantee accuracy of the information as it relates to State energy codes or other local and regional energy and sustainability requirements, or the interpretation and application of those requirements. Please consult official documentation from State and Local agencies as applicable.  

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