2016 Challenge Participant:

BPC Green Builders - Wemyss Residence

Applicant: Tom Wemyss

Project Address: Morningside Road, Norwalk, CT 06854

Bdrms./Sq. Footage: TBD

Builder Website: www.bpcgreenbuilders.com

Project Overview Project Specifications Project Team Project Photos
The BPC Green Builders - Wemyss Residence project in Norwalk, CT.

General project overview:

Four years ago, Tom and Lizzie Wemyss purchased an existing home in an established community of older homes directly on Long Island Sound. Less than two weeks after getting married, their home was destroyed by Hurricane Sandy. Tom and Lizzie knew that they wanted to replace their old home with a new home that reflected their environmental consciousness. Tom is a co-owner of PurePoint Energy, which designs and installs solar PV systems, so there was no question that the home would be green and energy efficient.  

Tom and Lizzie turned to BPC Green Builders to help them achieve their goal. BPC has been building high performance, energy efficient homes for sixteen years and welcomed the opportunity. Working with semi-custom plans created by the Wemyss’ home design firm, BPC created details for the thermal envelope and mechanical system that approach Passive House levels of performance and a net zero energy profile, with a final HERS score of -8.

Special Features:

  • Elevated home to avoid future hurricane damage

  • Covered porch across the full width of the house to capture cooling breezes off Long Island Sound

  • Open concept floor plan

  • Natural gas fireplace that can heat the entire house in the event of a power outage

Orientation and Envelope: (windows, insulation, framing)

  • House roof is oriented to solar south for PV system.

  • Home energy Rating Scored (HERS) score of -8, denoting net zero performance.

  • Blower door result of 0.81ACH50 nearly achieves PH standard of 0.60ACH50.

  • 1st floor was framed with 16” open-web trusses insulated with 16” of 1/2lb SPF (R-58).

  • Exterior walls sheathed with ZIP R-sheathing (OSB mated to a 1” sheet of polyisocyanurate rigid foam board insulation,) to reduce thermal bridging.

  • Exterior walls framed with 2×6’s at 24” spacing, insulated with 2” of 2lb SPF and 3.5” of 1/2lb SPF (R-34 exterior wall assembly, including ZIP-R sheathing).

  • 18” roof trusses filled with 1/2lb SPF (R-65).

  • European triple-glazed windows with u-values of 0.13 (roughly R-8).

  • Fiber cement siding installed over drainable weather resistive barrier.

Heating, Cooling, and Hot Water:

  • An air-source heat pump heats and cools the house. An exterior compressor is connected to wall-hung interior units, one in each room.

  • Hot water is provided by a condensing, natural gas, tankless water heater, which provides instant hot water with no storage losses.


  • An energy recovery ventilation system provides a carefully calculated supply of fresh air to maintain high indoor air quality. The ERV does double duty as it also is used for bathroom ventilation.


  • The electrical system included a 240 Volt charging station for an electric car.  Due to flood related codes, the electric panel was located in the 2nd floor utility room.


  • 24 SunPower Panels were installed to create an 8kW solar electric system with a 7kW inverter.  The solar has produced about 11,000 kWh’s per year which offsets more power than they use.

Resources Sustainability Features:

  • Home was kept intentionally small at 1,700sf to minimize resource use.
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