ADU Construction Services by Gustin & Sumida Construction
Gustin & Sumida Construction is a full-service ADU contractor serving the Sierra Nevada Foothills region. Whether homeowners are looking to expand their living space, generate rental income, or accommodate multigenerational living, the company offers a structured, end-to-end approach to building accessory dwelling units that fit the property, the lifestyle, and long-term goals.
The company specializes in both detached and attached ADUs, working with clients across communities including Grass Valley, Nevada City, Auburn, Colfax, Penn Valley, Meadow Vista, Alta Sierra, Foresthill, and surrounding foothill areas.
A Full-Service Approach to ADU Building
Gustin & Sumida Construction manages every phase of an ADU project, from initial design through final inspection. Their process is broken into four key stages:
- Design & Planning: The team works with homeowners to develop a layout that suits the property and intended use — whether that's a simple studio or a fully self-contained in-law suite or backyard cottage.
- Permitting & Compliance: ADU regulations in the Sierra Nevada Foothills vary by location. Gustin & Sumida Construction handles local zoning laws, permitting requirements, and building codes across Grass Valley, Nevada City, and unincorporated areas.
- Construction & Finishing: From site preparation and foundation work to framing, roofing, and interior finishes, the company manages all aspects of construction using materials suited to foothill climates.
- Project Management: Throughout the build, the team maintains clear communication, budget transparency, and reliable scheduling to keep projects on track.
Each detached ADU or attached unit is customized to the specific property rather than built from a generic template. This includes matching the design to the existing home and lot conditions.
What Gustin & Sumida Construction Brings to Each Project
The company has built its reputation in the Sierra Foothills through decades of residential construction experience and a working knowledge of local permitting and zoning requirements. They are licensed and insured, and project management is handled directly by experienced builders rather than delegated to subcontractors alone.
Key aspects of their service include:
- Decades of residential construction experience in the region
- In-depth knowledge of Sierra Foothills zoning and permitting processes
- Licensed and insured operations
- Hands-on project management throughout the build
- Honest estimates and dependable timelines
- Design tailored to match the existing home and lot
Gustin & Sumida Construction serves homeowners across the Sierra Nevada Foothills, including those in rural neighborhoods and historic downtown districts. Their ADU work covers a range of unit types — from granny flats and garage conversions to rural foothill studios and multi-use additions — depending on what the property and local regulations allow.
For homeowners in Grass Valley, Auburn, or the broader Sierra Nevada Foothills area considering an ADU project, Gustin & Sumida Construction offers consultations and project quotes to help determine what is feasible for a given property.
