Net Zero Off-the-Grid House
Annapolis, Maryland
Design and construction of this 3,200-square-foot residence had an aggressive mission – to provide a modern lifestyle for a family of four while minimizing their footprint on the Earth. For its Net Zero off-the-grid utilities approach, the house generates all electricity on site, sources all domestic and landscape water from rainwater capture or on-site resources, and manages storm water through capture or infiltration.
Hugh Lofting provided both design and construction management / general contracting for the project, utilizing a systems approach to construction that reduced site-generated waste and construction time while increasing quality control. Local tradespeople and natural, local, and/or recycled materials were used as much as possible, bolstering LEED rating points. The recycled content of the concrete was traced and documented to earn additional points. The house was designed and built to work with the earth, maximizing passive solar gain in the winter with shading from the summer sun. The beautiful structure will bring joy for generations.
A timber frame crafted in the Hugh Lofting shop sits atop a precast concrete foundation wall system and is enveloped by Murus Company Structural Insulated Panels (SIPs) that provide R-40 insulation on the walls and roof. Energy modeling shading simulation software was used to determine the most efficient percentage of windows to wall. Concrete floors and a real fireplace, crafted from Avondale Quarry stone, create a thermal mass to maximize passive solar gain.
The home is positioned to take advantage of prevailing winds for natural ventilation and is equipped with large, high-efficiency, operable windows throughout. Siting maximizes passive solar gain in winter with shading for summer sun. Hand-troweled, stained, and polished concrete floors and a fireplace crafted from Avondale Quarry stone create thermal mass that contributes to passive solar heat gain. Tight construction with seamless insulation are supported by radiant solar-powered floor heating. The same solar thermal system provides domestic hot water, backed up with a propane-fired instant hot water system. The mechanical system includes passive nighttime cooling through the solar thermal panels with a geothermal heat pump back-up. Healthy indoor air is maintained via an Energy Recovery Ventilator (ERV) that efficiently maintains temperature while introducing fresh air.
Architect/Contractor: Hugh Lofting Timber Framing & High Performance Building
Certification:
LEED for Homes Silver Certified