The Petaluma Pastoral project is an ongoing multi-phased endeavor set on 4½ acres of picturesque rolling farmland; two buildings have been completed so far – a third is in design phase.
As visitors arrive at the site, they are greeted by a curvilinear rural structure that implies a gateway to the property; it is the exterior wall for the guest house/garage/music studio. The irregular curved form, sheathed in vertical cedar planking, was designed to juxtapose with the orthogonally-designed house further up the driveway and to work as an identifiable landmark for the property.
The specific position and siting of the ADU is based on the idea of a procession: the sculptural presentation gives way to and reveals the residential façade as visitors ascend the winding driveway.
The returning clients had four main goals for the primary residence:
1) Energy efficiency – To answer, we employed several design strategies to maximize energy efficiency:
- Solar panels on the roof of both buildings collect 22 KwH, stored in a 10 KwH battery. This set up produces almost as much energy as the home consumes (96%).
- The roof overhangs are optimized to provide shade from the summer sun and solar gain in winter.
- High ceilings provide more room for hot air to rise and be exhausted through clerestory windows in the main living space.
- Cross ventilation is optimized throughout the home. The only mechanical air conditioning is in the primary bedroom.
- Radiant floor heat plus passive solar heating on the tiles (providing thermal mass), keep the home warm in winter.
- The roof and walls have maximum insulation to maintain desired temperature year round.
2) Aging in place – The clients intend this to be their forever home. To answer, the home has been outfitted with an elevator and all doorways and bathrooms have been designed wide enough to accommodate future mobility assistance. The design also combines living and sleeping areas on one floor of the home (upper) where 95% of daily activity takes place.
3) Entertaining – The clients wanted a house that would provide a big space for entertaining, but one comfortable enough for just two full time residents. In response, the architect designed the home for living on the upper floor, while creating the first floor as a separate entity, complete with a small kitchen, extra bedrooms, and family room – perfect for guests and visiting family.
4) Capturing views – The house is specifically sited and designed to capture panoramic views of the rolling hills and the prevailing afternoon ocean breezes via floor to ceiling windows and a deck that wraps around three sides of the home.
Design ChallengeThe lot is gently sloped pastureland and inserting a building into this landscape without ruining it was a major challenge. The buildings are low (one and two stories) and nestled into the hill on their upper sides. The house siting avoids the hill’s crest to avoid sticking out too much while also offering access to the views. A large swale that bisects the site was avoided to maintain pre-existing stormwater drainage patterns.
The clients wanted an energy-efficient, open, modern home with generous views of the surrounding landscape, space for entertaining, and provisions for aging in place. These were challenges of prioritizing southern exposed windows, for example, with view access. The solution: carefully studied overhangs to optimize solar gain and shading.
Budget constraints also challenged the energy saving mandate. To answer this challenge, passive design strategies (e.g. roof overhangs and optimized cross ventilation to stay cool in the summer, and tiled floors to act as a thermal mass in the winter) were prioritized. A well-planned building employing these strategies adds no cost to the client and keeps the cost of living low.
Physical ContextDespite being a new build, the home is designed to have little-to-no impact on the surrounding community and landscape, while providing a comfortable, secluded place for the clients to live happily.
The buildings are low (one and two stories) and nestled into the hill on their upper sides, avoiding the hill’s crest to avoid sticking out too much while also offering access to the views. Aside from the two built structures and the immediately surrounding areas, the land has been left intact. It utilizes low impact landscaping with natural vegetation, native California grasses, and plants that require minimal water. There is no lawn, and the landscaping in close proximity to the home meets California fire safe standards. The owners did add Olive trees (the only non-native vegetation) and a planted a vegetable garden to add to the home’s self-sufficiency.
One of the highlights of the site is the high-producing well, which fulfills 100% of the home's water needs. Because the well continuously produces ample water, there is no need to collect and store rainwater or implement grey water systems. Storm water is channeled downhill and dissipated on site.
Sustainability and energy efficiency were primary concerns during the design and construction processes. High-quality building materials and low-maintenance, durable finishes were chosen to increase the building’s lifespan and reduce the impact of care and upkeep.
Because of the home’s rural location, public transportation, bicycles, and walking are not available options. However, the client does own and operate electric vehicles, so charging stations have been installed at the home. These stations are offset by collected solar energy and 10kwH battery, thus reducing the clients’ carbon footprint while traveling to and from home.
Finally, the clients asked that the gorgeous rolling hills and landscape become a part of the home. As much as the home was designed to fit within its geographic location, it was also designed to bring that scenery to the home. Thus, floor-to-ceiling windows and a large deck were put in the design to connect the owners with their beautiful natural surroundings and bring these views into the home.