KMA worked with an owner couple who were planning to install a prefabricated A-frame on their Sonoma property for use as a rental accessory dwelling unit (ADU). KMA provided energy efficiency coordination, recommended systems and fire-resistant technologies, and assisted with permitting for the project.

Unlike traditional A-frames, this home was designed to prioritize thermal comfort and indoor air quality. A continuous layer of mineral wool insulation was installed on the exterior under the rainscreen cladding. This insulation, combined with mineral wool batts installed between the framing and high-performance glass in the aluminum-clad windows and doors, reduced the heating and cooling load of the building and improved comfort. A Lunos heat recovery ventilation system was installed to provide MERV-13 filtered and preconditioned supply air while facilitating heat recovery exchange with the exhaust air. Energy use was optimized using a mini-split heat pump system for space heating and cooling, a heat pump dryer, LED lighting, and daylighting via numerous windows and skylights. A multi-glide, glazed door opens fully to connect the double-height living space with the outdoor deck.

The finished home provides a comfortable and sustainable solution in a light-filled, tall, airy space. The property also had enough area to include an above-ground swimming pool. The couple fell in love with their new A-frame and decided to make it their own home after their kids move out.