Walnut Creek Hillside Detached ADU

This 1,200 sq ft detached ADU is built into a Walnut Creek hillside, pairing a master bedroom and two baths with an open-concept recreational and entertaining area.

ADU Type

Detached ADU

Duration

6 Months

Location

Walnut Creek, California

Size

1200

sq ft

The Opportunity

Building Into the Hillside

The property offered something most lots do not: elevation and a view. The challenge was turning a sloped hillside site into a comfortable, self-contained retreat, one designed less as a spare bedroom and more as a genuine destination for hosting family and friends.

Hillside site at 1340 Hermine Ave in Walnut Creek before ADU construction

Open-concept entertaining area inside the 1340 Hermine Ave detached ADU, Walnut Creek

What We Did

Engineered for the Slope

Vargas Construction designed and built a 1,200 sq ft detached ADU into the hillside over six months. The layout centers on an open-concept recreational area for entertaining, anchored by a master bedroom and served by two full bathrooms, delivering a complete, independent living space that works with the terrain rather than against it.

The Outcome

A Private Retreat for Entertaining

The finished ADU gives the homeowners a standalone space purpose-built for gathering, with an open entertaining area, a private master suite, and two full baths. Six months from start to finish, it adds both everyday livability and long-term property value.