The Grass House – 2019 Washingtonian Residential Design Award Recipient

Market: Residential
Type: Single-Family Home
Location: Washington, DC
Architect: Andrew Linn and Jack Becker of
Building Size : 695 sf
Certification: LEED for Homes v4: Platinum

Project Background:

This building was built on the property of the architect homeowner as a secondary structure able to be used as an office space. It is a standalone building designed with innovative features to maximize efficiency and try out new materials. 75% of the above grade envelope is a BamCore system, which is hollow bamboo wall panels. These panels were stuffed with wool insulation. An efficient mini-split heat pump was utilized for heating and cooling, while hot water is provided by a instantaneous hot water heater. A two-part Lunos through the wall ventilation system was installed that utilizes a ceramic core for ventilation energy recovery.

The interior materials and finishes include locally milled walnut stair treads, mycelium hanging lamps, a woven willow branch stair wall, and CaliBamboo flooring. Open floor space and design were considered for maximizing comfort. Everything from innovative insulated CMU blocks for foundation, to proper window overhangs, to recycled slate roofing was considered. A holistic approach to sustainability was important to the client/designer of the Grass House.


Project Services:

SWA provided sustainability consulting and was the Green Rater for the project. SWA also performed the manual J heating and cooling load calculations to confirm HVAC sizing and proper ventilation.

Primary Green Building Features:

  • Recycled roof slate and locally sources wood, where possible
  • BamCore wall panels to maximize continuous insulation and utilize renewable materials
  • Efficient heating, cooling, and water heating
  • Innovative and efficient heat recovery ventilation system
  • Charred shou-sugi-ban finish in place of paint or other applied finish, where possible


Read more about SWA’s Residential New Construction and Green Building Services

Listen to our podcast episode with Andrew Linn, Grass  House owner and architect, here!