High Touch Consulting logo

ADU Construction in the Bay Area

Detached, attached, and conversion ADUs — fully permitted, code-compliant, and built to maximize rental value or family use.

Detached new-construction ADU interior kitchen with gray Shaker cabinetry in San Mateo

California's ADU laws have transformed Bay Area properties into multi-unit assets. We design and build ADUs that comply with state ADU statutes and each city's local ordinances — from Palo Alto to San Jose to San Francisco — so the project moves fast and the finished unit holds long-term value.

What's Included

Every adu construction project from High Touch Consulting includes:

  • Detached ADUs (new construction, up to 1,200 sq ft)
  • Attached ADUs (additions to the primary dwelling)
  • Junior ADUs (JADUs) within the existing footprint
  • Garage conversion ADUs
  • Full architectural design and engineered structural plans
  • Title 24 energy compliance and CALGreen documentation
  • Independent utility metering when required
  • All trades: framing, electrical, plumbing, HVAC, roofing, finishes
  • Site work, foundation, and drainage
  • Permit submittals and full City inspection coordination

Why Homeowners Choose Us

We're a fully licensed California general contractor (CSLB #1008964) with 11 years of experience navigating Bay Area permitting, building departments, and the unique conditions of Peninsula and Silicon Valley homes. Every project comes with a fixed-scope written proposal, weekly progress updates, and a single project manager from start to final inspection.

Where We Work

We provide adu construction services throughout the San Francisco Peninsula, Silicon Valley, and Marin County, including San Francisco, South San Francisco, Daly City, San Bruno, Millbrae, Burlingame, San Mateo, Foster City, Belmont, San Carlos, Emerald Hills, Redwood City, Menlo Park, Stanford, Palo Alto, Los Altos Hills, Los Altos, Mountain View, Cupertino, Sunnyvale, Saratoga, Santa Clara, Campbell, San Jose, Portola Valley, Sausalito, Mill Valley, Tiburon, San Rafael.

Popular ADU Construction Locations

Recent Work

ADU Construction Projects We've Completed

Real adu construction projects we've finished across the Bay Area.

Detached ADU New Construction in San Mateo, CA

Detached ADU New Construction

San Mateo, CA · ADU Construction

View project →
FAQ

Common Questions About ADU Construction

How long does an ADU take to build?

Detached ADUs typically run 6–10 months from permit submittal to certificate of occupancy. Garage conversions and JADUs are usually faster.

What does an ADU cost in the Bay Area?

Detached ADUs commonly run $300,000–$550,000 depending on size, finishes, and site conditions. Garage conversions are typically $150,000–$250,000.

Do I need an architect?

We provide full design-build service including architectural drawings and structural engineering as part of one fixed-scope contract.

Can I rent out my ADU?

Yes — under California state law, ADUs can be rented out (typically with a minimum 30-day rental requirement; short-term rentals depend on your city's local rules). Many Bay Area homeowners rent ADUs as long-term housing for $3,000–$5,500/month.

Will an ADU affect my property taxes?

Adding an ADU triggers a reassessment of just the new construction value, not a full reassessment of the property. Your existing assessment under Prop 13 stays in place; only the new ADU value is added.

Do I need to live on the property to build an ADU?

No — under current state law, owner-occupancy is not required for an ADU on a single-family lot (JADUs are different and do require owner-occupancy). This makes ADUs valuable as both rental income and resale value.

Can the ADU have its own utility connections?

Some cities require independent utility metering for new ADUs; others allow shared utilities with the main house. We confirm during design and handle the utility coordination.

Are you a state-approved ADU builder?

We're a fully licensed California general contractor (CSLB #1008964). We design and build ADUs that comply with state ADU law and each city's local interpretation — from Palo Alto to San Francisco to San Jose.

Ready to start your remodel?

Get a no-cost on-site consultation and a fixed-scope written proposal from a licensed Bay Area general contractor.

Request a Free Estimate Call (844) 403-2911