Sebastopol Hillside Residence

Project Description

The Sebastopol Hillside Residence’s program was simple – design a home inspired by the site and within a limited budget. The 2250 square foot, 3 bedroom, 3 bath home was also to accommodate programmatic needs for a young family that are sure to change over time.

Before all else, there was a reckoning with a restrictive view easement across the property, leaving a limited area upon which to build. The quadrilateral shape and steep hillside further impacted the ability to lay out rectilinear forms best suited to a limited budget.

With the constraints in mind, the project was conceived to highlight the opportunities presented by the site. A grove of fir and oak trees at the furthest and highest point of the site would serve as the backdrop and formal inspiration for the house. The buildable area had a clear sweet spot – the obvious elevation from which the views from the house would be their most dramatic. The design then unfolded as a response to the requirements of the owners and the site itself.

Upon approach, the house presents its most public face and prominent feature. The two story window wall emphasizes the verticality of the site and hints at the views it offers. Paired shed rooflines are separated by a cross axis that mediates between the open front deck and a more intimate rear patio buffered by trees. The exterior cladding, budget-minded board and batten of cementitious panels, pushes beyond the typical into a shifting pattern that plays on the backdrop of the tree trunks. A horizontal counterpoint, the flying wall above the entry folds back into the house to become the parapet wall of the two story space, passing out again past the deck and ending in the stairwell, the final form of a three-part vertical composition.

To maximize living spaces within the limited floorplate, a singular line of circulation running from the entry to the stairwell, repeated at the second floor, both separates and links flexible spaces. With the pull of a pocket door, the main level bedroom becomes an en-suite for guests. The dining room can be screened off as a playroom for the children. A deep landing at the stair provides multiple use options – as reading area, office or homework zone. The stair opens to yet another flexible family and play space between the master bedroom and the shared children’s room that can easily be enclosed to become a fourth bedroom in the future. The depth of the two story space is intimate yet spatially dramatic – the set piece for conversation, reading or daydreaming.

The resulting residence serves the drama of approach and procession, rewarding with generous views and expansive flexible living space.

Design Challenge

Challenges faced in this project constituted a “quintuple threat”. Developing solutions was like working to thread a needle with five thick pieces of thread. There was the challenge of the:
  • view easement and setbacks reducing the buildable area to a third of the overall site;
  • dimensional minimums necessary for drive court maneuverability and compliant cross slope for the drive, complicated by the flag-lot parcel and the downhill slope across the site;
  • setting the house at its optimal elevation. The buildable area had a clear “sweet spot” elevation from which the views would be their most dramatic. Providing a paced uphill walkway from the drive court to this level while modulating site grading, drainage, on-site percolation, and the goal of balanced cut and fill for hillside construction required careful study;
  • building height that was limited to 30 feet above existing grade at any point - five feet lower than many other area jurisdictions;
  • budget. Schematic Design estimate revealed 30% of the budget would be devoted to grading, drainage, retaining and foundation work. A tight budget became even tighter.
Design choices were explored with the intent of solving two or more challenges at a time, while aiming to fulfill the owner’s wish for flexible space and to glean design inspiration from the fir and oak grove. Workable and balanced grading was achieved through careful study and coordination with civil engineer and landscape architect. The grading started with the determination of retaining wall heights to each side of the drive court. The terraced entry steps work together with retaining walls and landings such that neither handrails nor guardrails are necessary, allowing the user to focus on the surrounding landscape views and progress toward the fir-clad entry porch. Along the way, step treads extend into the landscaped hillside, providing a horizontal counterpoint to the vertical journey and becoming grade beams that stabilize the slope. Guests arrive at the main level elevation, which coincides with the optimal views to the north. The house itself fully occupies the allowable building envelope. Parallel shed roofs, that conceal budget-oriented membrane roofing, just touch the upper height limit and draw the eye up to the tree laden backdrop. The entry porch is scaled to moderate and integrate with the two story living space. It carries a roof deck off the master bedroom that also provides easy second floor egress to grade at the back. The main front deck provides multiple solutions too. It is a covered carport and is the mediating building element that keeps overall height within limitations. While the project’s limited buildable area necessitated a two story solution, the thought of a monolithic main level ceiling was unappealing to the owners. The set-piece of the project then became the two story space, providing significant design impact for the compact home. Its playful combination of mulled windows enclose the space at a modest price by using standard sizes and budget-minded fixed units. The double-height solution provides openness, height and light, yet is scaled to a more intimate depth – perfect for bean bag lounging on the main level in front of open sky and mountains beyond. The master bedroom enjoys a similar view over its parapet at the upper level. Meanwhile, warm air from both levels rise and escape through the operable skylight above. Per Wikipedia, - the word "innovation" can be defined simply as a "new idea, device or method". However, innovation is often also viewed as the application of solutions that meet new requirements. In the case of the Sebastopol Hillside Residence, its innovation can be defined as the strategic application of solutions that resolve complex requirements in pursuit of "commodity, firmness,  and delight” for the Owners.

Physical Context

Site opportunities and constraints served as the primary generators for connections between built and natural environment for this hillside home. The site, one of the last buildable lots inside the city of Sebastopol, is unique. While within walking distance to downtown and schools, the flag lot is hidden from view off the street, and so responses to context were focused on the opportunities and constraints of the site itself – its backdrop of mature firs and oaks, the restrictive view easement protecting the uphill neighbor, maneuverability within the flag lot parcel, views northward and the overall relationship to the topography of the hillside. Integration through a marriage of civil, landscape and building design was key in creating the connection between the building its surrounding natural setting. The landscape design emerged in response to the need for a reasonably paced uphill procession to the main entry, while modulating grading, drainage and construction impacts to the hillside site. Textured board-formed concrete retaining walls offer a nod to the grove at the site edge while mediating between car court and optimal grading of the hillside. Corner steps welcome guests from two directions. With an upward turn toward the entrance, the steps extend into the site as corresponding grade beams, providing slope stabilization and a geometric counterpoint to a round catchment basin. A rock-lined drainage swale integrates diagonally with grade beams that are part of the overall landscape composition at both sides of the drive. The swale and related catchment basins slow, sink and distribute the flow of rainwater. Low-water and low-maintenance plantings provide scale and texture to the hillside while offering small-scale wildlife habitat and nutrition for pollinators. Intense natural colors highlight the travel path - a literal and figurative connection between the natural and built environments. The site’s natural setting also impacted conditions for a solar array. The intermediate roofline, between the twin shed roofs, that moderates overall massing also provided a south facing roofline. However, sun angle analysis indicated that, unless tall trees were removed, solar panels would be ineffective. Instead, choosing Sonoma Green Power as the utility provider satisfied the owner’s desire (and city requirements) for green energy to support the new home. Should the shading trees at some point complete their life span, suitable roof area remains available for solar panel installation. Enhanced insulation and Low-E glazing exceed Cal Green minimums. Generous screened openings bring in the cross breeze through to two story volumes that in turn lead to operable skylights to evacuate warm air. Air conditioning is only used on the very hottest days.