From a challenging site rises a timber-filled, net zero family home

Abbott Hill, a family home located in Los Angeles, is a true collaboration between client and architects. The result is a net zero family home with loads of character and attention to efficiency throughout.

Residential homes are a major contributor to greenhouse gas emissions, with most emissions generated during the use of the homes. A net zero energy home can make its own energy onsite and it produces at least as much energy as it consumes.

Designed by Louis Wasserman & Associates, architect Louis Wasserman along with personal and professional partner M. Caren Connolly, landscape architect, faced many challenges, starting with a steep site location that was one degree away from being defined as unbuildable by the state of California.

Wasserman says, “We find that the most important step in architecture is defining the question. Once the question is defined, architecture follows.” To achieve that goal, the duo relies on a design development process they call narrative architecture. He continues, “We ask our clients to write a one-page narrative describing what they see, feel and do upon coming home to their “new” space.” With that information, the architect and landscape architect team can focus on creating a plan that marries the attributes of the site location with the needs of the client and a focus on sustainability.

Much of the efficiency within the Abbott Hill home comes from design elements such as the unique cedar rainscreen which is a vertically unimpeded airspace that provides ventilation for the exterior walls. The transpired wall releases hot air out the top of the wall. Internally, skylights and a vent chimney perform a similar task inside of expelling hot air during the day. At night, the skylights draw in cool heavy air that sinks to the lower level concrete slab on ground where it cools the home throughout the day.

With the exception of a propane BBQ or Weber grill, the home is completely powered by photovoltaic panels. California has recently implemented legislation that guides all new construction towards the use of solar panels. At the time of this project, the home was required to include space to install PV panels at a later date, but the clients chose to streamline the process and install them from the start.

Sustainable materials were chosen throughout the net zero family home, with a concrete slab used for thermal mass, cedar for the exterior, and black locust for the decking. The interior is lined in ACX plywood, which has been used on the floors, walls, ceiling and joinery. ACX is a very high grade of plywood and the ‘ACX’ refer to the grade of wood and glue used. The A refers to the front face and indicates a high quality veneer with a good grain. The C is the back face is rougher and may have some visible faults. Finally, the X describes the waterproof adhesive used in the construction of the plywood itself. Each layers grain is glued perpendicular to the previous layer to create a sheet.

The timbers are protected using a SIOXX sealant, which is a substance made from a combination of naturally-occurring silicon and potassium. It will protect the timber against the weather.

In addition, a rainwater collection system makes water harvesting easy.

Sustainability specs:
– Net zero family home – it produces all of its energy needs from rooftop solar panels
– No gas is hooked up to the home
– Extensive use of timber both externally and internally
– Timber finished with a natural sealant
– Concrete slab is used for thermal mass
– External walls are transpired and vented, keeping the home cool
– Skylights and a vent chimney release hot air during the day and draw in cool air overnight
– Home is naturally lit through extensive and well-placed glazing
– Rainwater is harvested

This project, designed for creative clients, takes advantage of sweeping views and a steep slope, with a juxtaposition of public and private spaces and a flirtation of light play throughout. A simple, clear plan and limited materials lead to a striking forever home.