Turner Residence Case Study

The Turner’s previous home was an extraordinary, but traditional house. Built over a hundred years ago, the yellow Victorian’s unique personality has made it a well-loved landmark in Larkspur. In imagining a new home, Ellen and David Turner wished to employ the very best contemporary thinking to create a house that would fit both the family and the community. They wanted the house to be as thoughtfully organized as David’s Minox and fun and stylish as Ellen’s Cinquecento. The new residence was to be beautifully simple and connected to nature. They wished their new home to be environmentally sensitive, and universally accessible. This dream home would be positioned to enjoy the unique property and views of the bay, be respectful of the neighbors and community, and serve as an example of the best of contemporary design.

When the house is in use, there is almost no house. The goal was to make a building disappear into the landscape. The site itself is stunning: the ridge line of an oak covered hill with views of Mount Tamalpais, the Bay, and beyond. The idea was to make a house that allowed for living on the ridge without diminishing the ridge and its vantage point. The roof springs outward from a solid core with no perimeter shear walls. Structurally, the house mimics the surrounding oaks with their branches extending horizontally from solid trunks. Under this floating roofline, an array of sliding glass panels can retract completely into the core. What remains is almost nothing: a pool patio with a shade canopy. Mirror panels on the core further veil the building. In the end the house mimics, reflects, and merges with the surrounding oaks.

The function of the home is orchestrated within a series of soft thresholds, blurring the line between inside and outside, between home and setting. With the glass walls pocketed into the core, the interior spaces flow out onto the adjacent terraces, landscapes, and panoramas. The living room sits high above the ground and surrounding oaks, opening to private yet expansive views of Mt. Tam and the green terrain. At the northeast side of the house, the dining room, kitchen, pool, and main terrace are effectively fashioned into a single unified indoor/outdoor living area.

The property is uniquely situated along the natural and city-mapped ridge line above Larkspur, a steep hillside heavily wooded with heritage-status trees. In working with the local planning agency, an appropriate response to preserve the ridge by minimizing the home’s presence was sought out. The key was not to build on top of the hill, but rather to build into the hill, with the remaining volume partially tucked into the earth, and partially threaded through the existing oak trees on site. This configuration also organizes the program. Private spaces are protected within the half buried lower levels, while public areas are wide-open to the landscape.

White, Edward T. Vocabulary of Architectural Forms. N.p.: University of Arizona, 1980. Print. (1)

Mount Tamalpais is the main protagonist of the site. This beautiful peak dominates the Marin County landscape and lies between the house and the Pacific Ocean. The home is arranged in such a way that views of the mountain are at various points framed, revealed, hidden, or reflected. In a way, the house can be read as a choreography of spaces and places that put the occupants in various relationships to the mountain. And Mt. Tam herself seems to join in this dance: at times in the spotlight, at times reflected by the house, at times backlit and in silhouette, at times obscured by the fog.

Mt. Tamalpais from Pt. San Quentin” Copyright 2009 by Tom Killion. (1)

First light pours over the Bay and washes the ridge in gold;
Depthless gray mist silences the morning air;
An embracing blue extends for miles encircling Mt. Tamalpais;
Dappled tree shadows dance on the ground;
Rolling white clouds lumber along in passing herds;
Reflected flashes of water mimic the swaying flight of crows above.

The naturally calming qualities of this Marin County ridge top have inspired an equally unique architectural response. Throughout the day, and all year long, this house offers wildly open access to the natural environs. In particular, the vitality of the light and sky is showcased and celebrated within every opening, edge, surface, perforation, reflection and shadow – Look just past these details, and the constantly shifting views both near and far appear, providing contemplative comfort.

An elegant structured system was designed in collaboration with Tipping Mar & Associates. To limit the building height across the ridge, two levels of the building are cut partially into the slope forming a grounded plinth. On top of this base sits the pavilion, completely open and sheltered under an elongated roof. Spread footings provide the foundation; floors are poured-in-place concrete slabs; and concrete masonry units (CMU) form the walls. Conversely, the roof structure is composed of steel beams covered by a lightweight steel deck, the outer ends of which are vertically supported by slender steel pipes. The roof framing is allowed to laterally cantilever almost 40 feet since it is anchored against wind and seismic forces at the CMU walls in the center of the building. The end result is a sleek and elegant building where the structure accompanies, but does not dominate, the design.

To more efficiently sequence the construction schedule, the Alaskan yellow cedar spa enclosure was pre-manufactured off-site, and delivered in pieces for installation. Using this process allowed the contractors to start fabrication of the spa enclosure while simultaneously pouring and curing the concrete for the pool, spa, and terrace. Manufactured cedar floor, walls, and ceiling components were fabricated to extremely tight tolerances for quick installation, precisely when needed. Off-site fabrication generates less construction-related waste, site erosion and pollution, and allows for a more flexible construction schedule.

The home’s design, with a perimeter that can be up to 75 percent open, presented an especially unique condition in terms of heating. Radiant heating integrated into the concrete topping slab offered the clear advantage of heating the occupants and the floor rather than the air within the space. Within the floor, a network of coils carrying heated fluid is strategically subdivided into heating zones to allow full temperature control in each room. The warm concrete mass functions as a continuous surface heater, heating the space above and allowing a person to comfortably walk around barefoot even in colder seasons.

The wealth of coast live oaks that dominate the natural hillside site were a key consideration in the home’s design – both in its relationship to the environment and the identity and feel of the interior. Along with various other species, the fifty-four oaks on site create a dense verdant screen of privacy and a variegated play of light and shadows throughout the home. Introducing the essence of the oaks into the space methodically enriches the interior quality of the home. By wrapping core components of the home with natural materials, the living spaces were infused with richness and warmth.

Fixed mirrored panels, glass guardrails, and sliding glass doors on the top floor span the gap between the buried plinth of the private level and the floating roof above the upper public level. This results in the house virtually disappearing.

From the pool terrace and exterior decks, the façade reflects the surroundings in such a way that the oak groves, mountains, and sky seem to occupy the house as if there is no material architecture. When the sliders pocket away, the top floor becomes part of the outdoors. Effectively there are no walls and the trees stitch together the front, side and rear.

A continuous curtain wraps around the entire top floor. When the glass doors are open, and the curtains are deployed, this entire level ripples in the breeze, further emphasizing the ephemeral nature of the enclosure.

Collaborating with Sherwood Design Engineers, site drainage was integrated early into the architecture and landscape design. Seasonal rains are managed onsite through multiple rain gardens which collect and control storm water runoff from the roof, decks, and pool terrace. This system decreases on site erosion and possible flooding to the city’s drainage downstream from the project site. As excess water soaks into the ground and is filtered through various levels of plant, soil and aggregate medium, potential pollutants are also reduced.

The façade was composed by layering operable transparent, translucent, and perforated screens for varied levels of day lighting, reducing the demand for electrical lighting. Additionally, the whole third floor can open up for natural ventilation or completely shut to hold heat. This completely elminates any need for a mechanical cooling system.

Fixed perforated panels provide a secure way to open certain windows in the evening for night cooling while allowing light to filter in during the day. Curtains are on a continuous track around the entire third floor to filter the sun during the day or provide privacy in the evening. All of these items can be layered in different combinations for a wide variety of conditions. In this way the façade is visually active, responsive to environmental conditions, and energy efficient.

The simplicity of the crisp design of the home is juxtaposed with the raw and natural qualities of the surrounding landscape. A densely vegetated series of stacked stone walls carefully sculpt a new approach to the home while maintaining the greenery and natural quality of the hillside. An irrigation system runs throughout the walls, and soil pockets in and around the blocks are planted with deer resistant species of plants. Over time, these plants will cover completely over the retaining walls.

There are many trees on the property (mostly Coast Live Oak and Bay Laurel) and several are large enough and old enough to be designated by the City of Larkspur as heritage trees. Unfortunately, sudden oak death had killed or infected a good portion of them. Arborists call this a “senescent” or declining forest. Working with Ray Moritz, a local arborist and an expert in tree preservation, we developed a plan to reverse the decline of the forest and restore its health. To preserve the majority of healthy growth on the site and restrict the spread of the disease, Ray recommended the immediate removal of all dead and sick trees. Maintaining as many healthy native trees as possible was key while native disease-resistant replacement trees were planted in an effort to begin the reforestation of the ridge.

As the civil engineer for the project, Sherwood Design Engineers was tasked with cutting a new driveway along the site’s steep frontage to make up nearly 30 feet of elevation over a short distance. Sherwood established parameters to reduce site impacts during grading activities and carefully analyzed all earth work to minimize the amount of soil off-haul. The entry approach and driveway retaining walls were built into the slope as much as possible to limit visual impacts to the neighborhood.

The topography also created structural challenges for the driveway walls. Rather than build a single massive retaining wall, Tipping Mar & Associates devised an economical way to retain the excavations using two-tiers of shorter concrete walls. The footings under these walls are supplemented with a series of 10-foot-long soil nails inserted into the hillside. A self-supporting modular block wall system is stacked in front of, and seismically tied to, the concrete walls using steel cables. This interlocking wall incorporates soil pockets that enable the entire surface to be planted with native vegetation, visually returning this cut to the natural hillside.

The furnishings lend to the open, relaxed qualities of the site and house. Nicole Hollis Interior Design worked closely with the client to select textures, natural colors, and forms that heighten the integration of the outdoors when the house is open and provides cozy comfort when closed.

Custom furniture pieces were handcrafted by local artisans, in some cases using the same white oak as the architectural woodwork used throughout the house. Fabrics were hand selected for texture, color and natural fibers that soften the spaces and, in the case of the curtains, glow with the sunlight as it tracks across the sky. The overall experience is that of a modern and luxurious retreat.

Project Information:

Project Name:  Turner Residence
Project Location: Larkspur, CA
Owner/Client: David and Ellen Turner
Type of Business/Use: Residential
Date of Completion: August 2013

Design Team:

Architect: Jensen Architects
Mark Jensen, Frank Merritt, Chris Kalos (project leads)
Ricardo Gonzalez, Robert Pei, Kyle Belcher, Chris Chalmers (project team)

Structural Engineer: Tipping Mar & Associates
Civil Engineer: Sherwood Design Engineers
Geotechnical Engineer: Miller-Pacific Engineering Group
Landscape Architect: Terra Ferma Landscapes
Land Surveyor: R.W. Davis & Associates
Waterproofing Consultant: Simpson Gumpertz & Heger
Interior Designer: Nicole Hollis Interior Design
Arboricultural Consultant: Urban Forestry Associates
Lighting Controls, A/V: North Shore Consulting
Acoustical: Charles M. Salter Associates
Model Shop: ZdP Models
Photographer: Mariko Reed, Ellen Turner

Construction Data:

Contractor:  Johnstone-McAuliffe Construction, Inc.
Suppliers: Fleetwood (aluminum sliding doors and windows)
Exotic Hardwoods (wood veneer)
Concrete works (hearth/bench, and fire pit)
Hamilton Cabinets, Elements Casework (casework)
Dzine (Boffi products)
RSA, Xenon, Aion LED, ACDC, Bega (lighting)
Burris Window Shades (curtains, shades)
Tropicana Pools (swimming pool, spa)

Major Materials: Cast-in-place concrete; Portland Cement Plaster; Mirror Panels; Mill Finish Perforated Aluminum Panels; Aluminum Window and Door Systems; Linen Curtains; White Oak Cabinets & Shelves; White Oak Counters; Stainless Steel Counters; Steel Stair; Glass Guardrails; Precast Concrete

Size/Floor Area: 5,302 sq.ft. (+7,710 sq.ft. Decks & Terrace)