A Glass-Walled California Retreat Designed to Blend Into Nature

On 20 acres in West Marin, north of San Francisco, a remarkable home demonstrates how architecture can complement rather than compete with its surroundings. Designed by Bay Area architect Jeremy Kotas and completed in 2005, Mountain King is a glass-walled residence set within a restored native meadow, with Mount Tamalpais on the horizon and protected parkland beyond its boundaries. Now on the market for $4.4 million, the property is a considered exploration of sustainable design, natural materials and the relationship between house and landscape.

The project began two decades ago, when Scottish surgeon Kenneth Hillan and South African finance entrepreneur Duncan Robertson purchased an undeveloped parcel in search of a distinctly Californian way of life. Having previously commissioned Kotas to remodel their San Francisco home, the couple returned to the architect with what they describe as a true “blank sheet”.

Kotas, a UC Berkeley-trained architect who worked for Frank Gehry early in his career, brought an unconventional sensibility to the project. His architectural approach combines Modernist principles with regional references, historical details and a sensitivity to context. At Mountain King, soaring ceilings, expansive glazing and a south-facing orientation establish a strong connection with the outdoors, while walnut floors, natural stone and radiant underfloor heating bring warmth and comfort to the interiors.

The kitchen is fitted with Poggenpohl cabinetry, Gaggenau appliances and Sub-Zero refrigeration, while the principal bathroom features natural stone and Boffi fixtures. Automated blinds, generous glazing and carefully positioned roof overhangs help manage changing light and seasonal conditions.

A Meadow and a Mirror-Like Pool

If Kotas shaped the architecture, landscape designer Bernard Trainor determined how the house would sit within its surroundings. The Australian-born founder of Ground Studio is known for landscapes that blur the distinction between cultivated and wild, and his work at Mountain King follows this philosophy.

Rather than imposing a conventional manicured garden on the acreage, Trainor worked with native planting, including purple needle grass, yarrow, lupins, poppies, manzanita, madrone and coastal live oak. A century-old bay tree anchors the landscape, while seasonal flowers and grasses allow the meadow to change throughout the year.

The intention, according to the homeowners, was for the property to look “almost like California was before it had been farmed”.

The most striking intervention is the heated 25-yard lap pool, which sits within the meadow and is approached via broad concrete steps. Designed around the owners’ shared passion for competitive swimming, it feels less like a conventional recreational feature than a reflecting pond embedded in the landscape. On still evenings, the water mirrors the sky, while surrounding grasses soften its geometric form. An adjoining spa offers a place to take in the night sky.

The project attracted wider attention in 2008, when The New York Times featured it in A Sustainability That Aims to Seduce, highlighting an approach to environmentally conscious landscape design that prioritised beauty alongside restraint.

Architecture, Art and a Sense of Escape

Sculptural metalwork by San Francisco master blacksmith Jefferson Mack introduces another layer of craftsmanship. His pieces sit within the landscape as artistic interventions, complementing the architecture without distracting from the natural setting.

Beyond the two-bedroom main house, a separate guest house provides a bedroom, sleeping loft, kitchenette and private patio. Courtyards, dining terraces, vegetable gardens and an elevated deck beneath mature oaks create further opportunities to enjoy the property outdoors. A 48-panel solar system adds to its environmental credentials, while direct access to nearby state parkland connects the home to the wider landscape.

For Hillan and Robertson, the property became a full-time residence during the pandemic, having initially been conceived as a retreat from city life. “California has been extraordinarily kind to us, and this home was the manifestation of a California lifestyle we could only have dreamed of prior to making the Bay Area our home,” they say.

Now relocating to Cape Town to be closer to family, the owners are passing on a property shaped by a particular vision of California living. At Mountain King, architecture, landscape and art work together to create a home that feels immersed in its setting, offering a quieter alternative to the conventional country estate.

Credits

Images: Context Visuals / Alex Zhiglov