Low Cost/Low Energy House creates a dwelling that is sustainable in the broadest sense: low cost to build and to purchase, extremely low-energy, long-lasting, and of minimal impact to the environment. Based on the vernacular shotgun typology, the affordable, low-energy, single-family Low Cost/Low Energy House will help to revitalize the existing neighborhood of the Lower Ninth Ward.
Organized linearly along a circulation corridor, the long axis of the house runs East/West. This organization addresses strategies of natural ventilation, daylighting, shading and solar heat gain. The south facade's deep roof overhang is calculated to provide passive solar protection for the building's interior in the summer, while allowing passive solar heat gain in the winter. Sliding panels on the south facade offer flexibility and protection from sun, rain and wind when required. Windows on the north facade provide abundant daylight and natural ventilation while limiting solar heat gain. If required for a North/South long-axis orientation, the facade with the large sliding panels would be the West facade, achieving many of the same benefits as the optimal southern exposure.
The house reinterprets a traditional shotgun-style plan by mirroring two bedroom and bathroom units on either side of the main living space. The open living plan optimizes natural air flow and daylighting. The corridor opens southward to a flexible cantilevered side gallery that wraps around the house, providing shaded outdoor living space. The flexible boundary between the corridor and gallery can adapt to the changing needs of the family throughout the seasons.
To achieve Passive House Standard, this house employs an airtight, thermal-bridge free and super-insulated envelope combined with passive shading in the summer and solar heat gains in winter; concrete floor topping for thermal mass to temper solar heat gain and to re-radiate the heat into the space as required; daylighting; natural ventilation and cooling; and highly reflective self-ventilating galvalume cladding. Additionally, a balanced energy recovery ventilation system and split-zoned high-efficiency heating and cooling units with an ultra high-efficiency on-demand water heater for domestic hot water and supplemental radiant floor heating reduce primary energy needs. The use of low-cost, durable and long-lasting materials, and proven construction techniques assures value to returning homeowners. In accordance with post-Katrina building codes, guidelines and best practices, the house is raised 7 feet above grade, securing its safety during flooding and providing shaded parking, storage, and outdoor living spaces. The high albedo, recyclable galvalume roof and wall cladding minimizes solar heat gain and provides a lasting 'lifetime' cladding material.