HMM and Hector did an outstanding job building me an ADU, from dealing with Palo Alto inspectors and permits to work quality. Communication was also outstanding. I’m very happy and have used them again for smaller jobs on the main house. Highly recommend!
General Contractor
Home Additions in San Francisco, CA
HMM GC Inc. builds home additions for San Francisco homeowners who need more space without moving.
- Added square footage increases your home's resale value in a high-demand San Francisco market
- Structural work is designed to meet San Francisco's seismic and Title 24 energy code requirements
- One general contractor manages all trades, reducing coordination gaps and miscommunication
- Addition is designed to match your home's existing roofline, siding, and exterior details
- Foundation and framing are assessed before design begins, avoiding costly mid-project changes
- Expanded living space lets your household grow without the cost and disruption of relocating
Expert Home Additions in San Francisco, CA
Home additions in San Francisco require more than extra square footage. They require a general contractor who knows the city's building codes, seismic standards, and Title 24 energy requirements. At HMM GC Inc., we plan and build additions that work with your existing structure, not against it. San Francisco's housing stock is largely Victorian and Edwardian, built on narrow lots with tight setbacks. That means every addition starts with a close look at your foundation, framing, and lot lines before any design decisions are made. We coordinate architects, structural engineers, and licensed trade subcontractors under one contract. You work with one team from planning through final inspection. Whether you need a rear extension, a second-story addition, or a converted garage space, we scope the work honestly and build to code. If you own a home in San Francisco and need more room, call HMM GC Inc. to schedule a site walkthrough.
What's included
- Added square footage increases your home's resale value in a high-demand San Francisco market
- Structural work is designed to meet San Francisco's seismic and Title 24 energy code requirements
- One general contractor manages all trades, reducing coordination gaps and miscommunication
- Addition is designed to match your home's existing roofline, siding, and exterior details
- Foundation and framing are assessed before design begins, avoiding costly mid-project changes
- Expanded living space lets your household grow without the cost and disruption of relocating
Licensed General Contractor
Real Estate Expertise
Detailed Project Communication
Quality Craftsmanship
Bay Area Specialist
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FAQ
Home Additions FAQ
Common questions about home additions in San Francisco, CA.
Yes, we build second-story additions for San Francisco homeowners. We assess your existing foundation and framing first to confirm what the structure can support.
Most single-family homes in San Francisco can accommodate a rear addition, depending on lot size and zoning setbacks. We review your property details during a site walkthrough before any work is planned.
Yes, we design the addition to align with your home's existing exterior, including roofline, siding, and window style. Matching the original structure is standard practice for homes in San Francisco neighborhoods.
Yes, a licensed general contractor is required for structural additions in San Francisco. HMM GC Inc. holds the required license and manages all subcontractors and inspections.
We build rear extensions, second-story additions, and converted garage spaces for San Francisco homeowners. Each project is scoped based on your lot, structure, and space goals.
Contact HMM GC Inc. to schedule a site walkthrough at your San Francisco property. We review your existing structure, lot conditions, and goals before outlining next steps.
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Phone
(650) 255-2148Hours
- Monday 8:00 AM - 5:00 PM
- Tuesday 8:00 AM - 5:00 PM
- Wednesday 8:00 AM - 5:00 PM
- Thursday 8:00 AM - 5:00 PM
- Friday 8:00 AM - 5:00 PM