California-based studio Donaldson + Partners has designed a circular house partially embedded in the landscape with large concrete parabolic arches in Montecito, California.

Seven years in the making, the 14,000-square foot (1,300-square metre) house is sunken into a four-acre lot between the Santa Ynez Mountains and the Pacific Ocean, outside Santa Barbara.

Robin Donaldson, founder of Donaldson + Partners, envisioned a "house for the twenty-first century" for a pair of artists that tests the relationship between landscape, art and experience.

"We were inspired by the combination of incredible site and visionary clients to keep pushing the design, which resulted in a house that both emerges from and is part of the landscape; that acts as backdrop to both the rhythms of daily life and two vibrant art practices; and that entirely redefines what we imagine a house could be," Donaldson told Dezeen.

Donaldson worked closely with the owner to design the circular structure so that it  "emerges from and burrows into the landscape."

Topped with solar panels and a landscaped rock garden roof, the concrete and glass house is accessed by a suspended metal walkway that approaches a semi-circular door and a "wormhole" entry into the house.

Inside, a great room is lit with natural light from concave glazing on the east and west sides. It opens to dual courtyards – the eastern "avocado-shaped" courtyard with seating and a staircase around the perimeter and the western pool deck and rectangular pool that radiates out from the centre of the plan.

Opposite the entrance, the offices, living, dining, and kitchen spaces join the primary suite to form a pie-shaped wedge, within the centre of which sits a circular private courtyard.

Staircases distributed around the plan descend to the lower level, which holds two guest suites, a game room, library and theatre – as well as a painting studio, pottery shop, and large garage workshop that leads out to a motor court that encircles a quarter of the round plan.

On the lower level are a game room, library, and theatre. The exterior patio leads to a drawing/painting studio, ceramics studio, and terraced amphitheatre, which merges back into the landscaped and adjacent sculpture garden, melding everyday living and a profound connection between architecture, landscape, and art.

"Practically and programmatically, the owners needed a place to support their social and philanthropic lives and their thriving art practices, while also providing a sense of privacy," the team said.

"Working between the monumental scale of the overall envelope and the playful interior spaces, the design creates a comprehensive formal articulation on the exterior and a generous flow on the interior."

The Hill House Montecito is part of Donaldson's evolution into a more artistic practice, according to the studio.

Further north is Cupertino, California, Apple recently unveiled its subterranean Apple Park Observatory, which features similar rounded openings and planted roofs over a concrete bubble dome.

The photography is by Joe Fletcher

Project credits:

Concept and ideation: Robin Donaldson, Bruce Heavin
Fabrication: F Myles Sciotto, DplusWorkshop, Neal Feay Co, Stonemark Construction
Contractor: Matt Construction