Custom ADU Builder & In-Law Suite Construction in Danville, CA
Turnkey Accessory Dwelling Unit (ADU) Solutions in the Bay Area
Detached Accessory Dwelling Units (Standalone Homes)
- Fully custom detached secondary residences built from the ground up for multi-generational living, aging-in-place family members, or long-term rental income.
- Open floor plans, full chef kitchens, master suites, private laundries, and individual exterior patio spaces.
Attached ADUs & Home Additions
- Seamlessly integrated home extensions sharing a structural wall with the primary residence.
- Engineered architectural designs matching existing home rooflines, exterior siding, trim, and structural finishes.
Garage Conversions & Interior Conversions
- Transforming underutilized attached or detached garages into modern, fully permitted studio or one-bedroom living spaces.
- Sub-floor leveling, structural reinforcement, insulation, egress window additions, plumbing rough-ins, and dedicated HVAC installations.
JADUs (Junior Accessory Dwelling Units)
- Space-efficient living conversions created within the existing footprint of the main home (up to 500 sq. ft.).
- Efficiency kitchenettes, independent exterior entrances, and shared or dedicated sanitation facilities.
The End-to-End ADU Construction Process
Step 1 – Feasibility, Feasibility Study & Site Evaluation
Evaluating lot size, setback requirements, utility access (water, sewer, gas, electrical capacity), and local zoning ordinances in Danville and Contra Costa County.
Step 2 – Architectural Design, Engineering & Title 24
Drafting custom floor plans, 3D exterior renderings, structural engineering calculations, and Title 24 energy compliance documentation.
Step 3 – Permitting & City Approvals
Navigating SB 9/ADU state laws and submitting architectural construction plans to municipal building departments for streamlined permit issuance.
Step 4 – Ground-Up Construction & Utility Tie-Ins
Managing foundation pours, structural framing, roofing, trade rough-ins (electrical, plumbing, HVAC), insulation, drywall, and luxury interior finishes.
Step 5 – Final Inspection & Turnkey Delivery
Completing municipal building inspections, final utility connections, fixture testing, and handing over a fully certified, move-in ready ADU.
Frequently Asked Questions About ADU Construction
How much does it cost to build an ADU in Danville, CA?
The cost to build an ADU in Danville and the East Bay varies by type and size. Garage conversions generally range from $120,000 to $180,000, while new custom detached ADUs (typically 500 to 1,200 sq. ft.) range from $220,000 to $400,000+ depending on site grading, utility extensions, and finish levels.
What is the maximum size ADU I can build in Danville or Contra Costa County?
Under California state law, local jurisdictions must allow detached ADUs up to 800 square feet with 4-foot side and rear setbacks. Danville and Contra Costa County regulations generally permit detached ADUs up to 1,000–1,200 square feet depending on lot size and underlying zoning guidelines.
How long does it take to design, permit, and build an ADU?
The full ADU process typically takes 6 to 10 months. Planning, architectural design, engineering, and city permit approvals generally take 2 to 4 months, while actual physical construction requires 4 to 6 months from foundation pour to final inspection.
Does building an ADU increase my property value in the Bay Area?
Yes. Building a permitted ADU adds immediate structural square footage, increases resale appraisal value, and creates passive rental income potential or dedicated space for multi-generational family living in high-demand Bay Area markets.
Why Choose LTG Construction Inc. for Your ADU Project?
Over 18 Years of General Building Expertise
Constructing custom homes, additions, and structural projects across Danville, Blackhawk, San Ramon, and the East Bay since 2007.
Fully Licensed, Bonded, and Insured
California General Building Contractor License #938245.
Single-Source Design-Build Execution
One dedicated team handling site feasibility, architectural design, municipal permitting, utility infrastructure, and luxury residential construction.
Request an ADU Consultation in Danville, CA
Contact LTG Construction Inc. Today
Phone: (510) 472-6767
Service Areas
Danville, Blackhawk, San Ramon, Walnut Creek, Dublin, Pleasanton, and the San Francisco Bay Area.
Business Hours
Monday – Friday: 8:00 AM – 4:30 PM
Saturday - Sunday: Closed