Kaplan Thompson Architects
One of the few residential practices that publishes embodied carbon per project.
What they're known for
A Portland, Maine architecture firm working in Passive House, deep-energy retrofits and affordable housing, with a Phius competition win confirmed by the certifying body rather than the press release.
Kaplan Thompson Architects is a Portland, Maine practice working across Passive House homes, deep-energy retrofits, affordable housing, and institutional projects. The firm publishes embodied-carbon figures and detailed wellness specifications more consistently than most residential practices, while projects such as Spark Side carry independent Phius certification and award recognition. Its strength is documentation: envelope performance, ventilation, materials, and carbon are treated as part of the design record rather than left as broad sustainability claims.
Capabilities
- Architectural Design
- Deep-Energy Retrofit
Performance focus
- Passive House
- Low-Carbon Construction
- Healthy Materials
- Thermal Comfort
Credentials
PHIUS+ 2018 Source Zero
Achieved on Spark Side in Durham, NH, confirmed by Phius. A retired certification name and the predecessor of today's Phius ZERO.
Phius Certified Consultant (CPHC)
Kai Fast, confirmed on Phius's Spark Side project record. The firm also claims the credential for Jesse Thompson, along with being first in northern New England to hold it; neither is independently confirmed.
EPA Indoor airPLUS
Stated by the firm for Spark Side. Not independently confirmed against EPA records.
AIA New Hampshire Merit Award, Excellence in Architecture Design – Residential
2025, for Spark Side, confirmed by AIA New Hampshire. The jury comment: a great example of what we should be doing more of in these passive houses.
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Sources
Facts verified July 2026. Compound is an independent editorial directory and is not affiliated with this company unless stated.