PROJECT DESCRIPTION Teaberry is a master suite addition to a simple, single-story mid-century house on a wooded lot overlooking the northern San Francisco Bay. The owners dreamed of a serene, modern retreat immersed in the nature. Architecture, landscape and interior design form a unified narrative about dwelling on this spectacular hillside site. The addition telescopes eastward from the existing house, navigating changes in topography as the land slopes away. Teaberry’s functional program includes a bridge, a porch, a bedroom and bath. Teaberry’s metaphorical program is nature present in five classical elements: earth, fire, water, air and aether. As the addition extends across the site, the form modulates to resist and yield to the earth's force. The fossilized-limestone fireplace connotes primal simplicity. Water’s salutary effects extend from the Bay to the bath’s restorative tub and porch-like shower. Large openings admit the sky, daylight and wind. The fifth element, similar to the Japanese concept of "ku", is "the void" found in the double-cantilevered roof and porch, which creates dualities such as "above and below" and "inside and out" for spiritual contemplation. SITE CONDITIONS AND STRATEGY Since there was level ground adjacent to the existing house construction appeared easy. The geotechnical report, however, proved otherwise as a history of slides and varying depths to bedrock were revealed. Hillside retention, water management, installation of a light-commercial grade sprinkler system throughout the whole house and wildfire resistance required substantial resources. More than 30 piers and a 50ft long retaining wall help mitigate hillside movement. Bioretention planters, swales and extensive site drainage help deter erosion. Exterior materials and landscape management address California’s strict Wildland Urban Interface environmental code. Despite the building’s horizontality, the addition is a study in section. The floor of the existing house is at grade but the addition is raised up two feet, establishing its own datum. At the house, the hill flows under the bridge and out to the bay side. In the middle, the bedroom cantilevers over the foundation, creating a shadowed separation between wall and ground. At the end, under the bath, a concrete mechanical room anchors the building to the slope. Minimizing excavation and foundation area provided both cost-savings benefits as well as expressive opportunities. ADDITION DESIGN The expanded building is read as a “modulated bar.” The new exterior has its own material language but is compatible with the original construction. Orange MDO panels announce the joint between old and new while unified overhangs and a dark palette maintain massing continuity. Small-scale, cedar siding is a quiet departure from the original wide planks which are aggressively differentiated. Warm-black stain adds depth and dimension to the cedar surface in contrast with the flat black paint on the older siding. Board-formed concrete used in the retaining wall and foundation visually connects landscape and building forms as one concept. The voluminous interior breaks with the older building’s small rooms and openings. Multi-slide doors and 16ft vanities emphasize the horizon while the limestone-clad fireplace adds an elemental vertical counterpoint. Coffee-stained wood floors and warm gray tile temper the sun. Light is transmitted through clear, translucent and mirrored glass. Porcelain wall tile impressed with linen from tofu production; hand-set ceramic tile with a mottled, reflective glaze; and the grain of book-matched maple add intimate, tactile textures within the minimalist language.