In the heart of a densely populated Washington, D.C. neighborhood that has easy access to public transportation and bicycle routes, this historically-protected Georgetown rowhouse (circa 1800s) received a restoration treatment that brought it into the 21st century and helped it to achieve LEED Platinum certification.
Environmentally sustainable modifications to the 3,300 square footÂ home came in at $269 per square foot and had to be approved by the neighborhoodâ€™s stringent historic preservation review process.
The low-lying area creates a need for careful erosion controls. Disturbed topsoil had to be stockpiled and protected, stormwater runoff paths and velocities needed to be controlled, sewer inlets required added protections, and additional erosion barriers and swales were necessary. Gravity drainage for the foundation was installed on the exterior and interior to direct water to a sump pit.Â The new concrete basement slab includes a drainage mat below a foam insulation board that is topped with wire mesh reinforcement and thick-mil plastic. Basement walls and roof rafters are insulated with closed-cell, high soy-content spray foam.
Erik Hoffland Architect designed a three-story addition at the back of the house to preserve its historic character on the faÃ§ade, while Landis Construction restored the faÃ§adeâ€™s original windows with the addition of high-efficiency wood storm windows and weatherstripping.
Other sustainable features that contributed to the house achieving LEED Platinum include the following:
- A new reflective roof is home to a newly installed solar thermal hot water system.
- Advanced framing techniques of FSC-certified dimensional lumber, plywood, and interior stair systems conserved wood, optimized the size of insulation cavities, and limited thermal bridging.
- Wallboards are made of paper and gypsum that contains high levels of recycled content.
- Flooring on the middle and upper floors is made from salvaged heart pine.
- Walls are covered with Green Seal-certified primers and paint.
- Non-metallic piping is from Fusiotherm.