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Residential Marin County, CA

Ridgeline Residence

A sculpted hillside home that disappears into the oak canopy — post-and-beam structure, rammed-earth retaining walls, and floor-to-ceiling glazing aligned to the winter solstice sunrise.

Project details
Location
Marin County, CA
Year
2024
Size
6,800 sf
Duration
22 months
Budget
$4.2M
Architect
Holloway + Marsh Architecture
Before & After — drag to compare

The Challenge

The 2.4-acre sloped site presented a 38-foot grade change across the building envelope. Existing heritage oaks constrained the foundation footprint, and the county required a geotechnical study before any grading could begin. The client's vision — a single-level home that reads as landform rather than imposition — demanded a structural approach that had never been used on this ridge.

Our Approach

We proposed a hybrid post-and-beam over a concrete plinth. Six micro-pile caissons drilled to bedrock eliminated mass grading. The floor plate steps with the terrain in three separate decks, each two feet lower than the last, connected by brushed-steel bridges. Rammed-earth perimeter walls source soil from the excavation itself — zero off-haul, maximum thermal mass.

The Outcome

The completed home earned a 2024 AIA Bay Area Honor Award. Heating and cooling loads came in 44% below Title 24 baseline. The three heritage oaks remain within 6 feet of the structure, their root zones protected by a permeable gravel deck rather than poured concrete.

Disciplines
  • custom home
  • hillside
  • rammed earth
  • post-and-beam
  • passive solar
By the numbers
6,800 sf
Square footage
38 ft
Grade change
3
Heritage oaks saved
−44%
Energy vs code
22 months
Duration
AIA Bay Area Honor
Award