Energy Star Homes, Net Zero Energy Homes & Positive Energy Homes, Whole House Deep Green Retrofit Renovations, Zero Energy Ready Homes

Greenwich DER

Contemporary update of colonial home image

This positive-energy house was built in the 1930’s with various additions and renovations occurring over the years. The goal was to completely update both the exterior and interior of the house to accommodate the tastes and open-plan lifestyle of a family with young children. At the same time, the plan was to dramatically upgrade the thermal envelope and mechanical systems so that the house offered the high energy efficiency and other high-performance qualities of a new house built to meet demanding third-party certification standards.

This was the 2020 Fine Homebuilding project house and was featured in numerous videos.

Type: Contemporary update of colonial

Project Architect: Trillium Architects

Special Features

  • European triple-glazed doors and windows with traditional muntin bars
  • Standing seam aluminum roof for durability and recyclability
  • Newly finished attic space with media room, bar, and pool table
  • Glass handrails and guardrails for updated entry area and stairs
  • Direct vent wood fireplace in family room
  • LED vapor fireplace between kitchen and living room

Green Building Approaches

  • Excellent blower door test result of 0.85 ACH50.
  • Positive-energy house meaning that the solar PV system on the roof generates enough electricity to fully offset the energy required to operate the house over the course of a full year.
  • Siding and trim made from recycled waste product will last the life of the home.
  • Insulation products selected to minimize home’s carbon footprint and to significantly exceed building code minimum requirements.
  • Mineral wool batts used for 11” framed double walls and dense-pack cellulose for new 18” roof trusses.
  • Wood fibers in cellulose insulation sequester carbon and have unique moisture management properties.
  • Framed walls have continuous 1.5” layer of mineral wool board insulation.
  • Expanded polystyrene foam board insulation used over existing slab.
  • Closed-cell spray foam with low-GWP blowing agent used at basement/crawl exterior walls and existing roof framing.
  • Smart vapor retarder used at framed walls and new roof to prevent cold-weather vapor drive into wall and roof assemblies.


2022 AIA CT Sustainable Architecture Award

Project Year
HERS Score
Type of Home
Contemporary update of colonial
Project Size
9,000 Square Feet