Home Additions in San Francisco, CA

HMM GC Inc. builds home additions for San Francisco homeowners who need more space without moving.

Call (650) 255-2148
  • 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
A completed rear home addition on a San Francisco residential property, showing new framing and exterior siding matched to the existing Victorian-era structure. The addition extends the home's footprint toward the rear of a narrow city lot.

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

Need this service?

Get a clear roof assessment before you commit.

Call Now

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.

Still have questions?

Call us directly. Real answers, no scripts.

Call (650) 255-2148

What homeowners say.

5.0
3 Google reviews

Worked with us?

Leave a Review

The attention to detail on our kitchen remodel was impressive from start to finish. Everything was communicated clearly and the crew respected our home throughout the project.

Diana R. Google review

We hired HMM GC for a bathroom remodel and could not be happier with the results. The owner was straightforward, easy to reach, and the finish work looks excellent.

Marcus T. Google review

Our home addition came out better than we pictured. The team was professional, kept the site clean every day, and the framing and trim work were done with real care.

Priya S. Google review

Proudly Based in ,

Call, or book online — we're always available when you need us.

Hours

  • 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