ADU Construction in San Francisco, CA

HMM GC Inc. builds ADUs for San Francisco homeowners looking to add livable space to their property.

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  • Adds a fully independent living unit to your existing San Francisco property without purchasing new land
  • Garage and basement conversions make use of underutilized space already on your lot
  • A completed ADU increases your property's assessed value and long-term resale potential
  • Rental income from a legal ADU can offset your monthly housing costs in a high-cost city
  • Multi-generational households gain private, separate living space for family members on the same property
  • Professional coordination through San Francisco's multi-step city review process reduces costly errors and delays
A newly constructed detached ADU in a San Francisco residential backyard, showing a finished exterior with a private entrance and landscaped separation from the main house. The unit reflects the compact, code-compliant construction style common to San Francisco infill properties.

Expert ADU Construction in San Francisco, CA

ADU construction in San Francisco gives homeowners a practical way to add a fully independent living unit to their existing property. HMM GC Inc. handles the full scope of work, from site assessment and design coordination to structural build-out, electrical, plumbing, and final inspections. We work with garage conversions, basement conversions, attached additions, and detached new builds. San Francisco's zoning rules vary by district, and the city's Planning Department holds projects to detailed building standards, including minimum ceiling heights, energy compliance, fire safety requirements, and setback rules. Navigating those layers takes a contractor who knows the local process. We manage the documentation, coordinate with inspectors, and keep your project moving through each city review stage. Whether you want to house a family member, generate rental income, or add long-term value to your property, ADU construction is one of the most direct ways to get there. Call HMM GC Inc. to talk through what your San Francisco property can support.

What's included

  • Adds a fully independent living unit to your existing San Francisco property without purchasing new land
  • Garage and basement conversions make use of underutilized space already on your lot
  • A completed ADU increases your property's assessed value and long-term resale potential
  • Rental income from a legal ADU can offset your monthly housing costs in a high-cost city
  • Multi-generational households gain private, separate living space for family members on the same property
  • Professional coordination through San Francisco's multi-step city review process reduces costly errors and delays
Licensed General Contractor
Real Estate Expertise
Detailed Project Communication
Quality Craftsmanship
Bay Area Specialist

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ADU Construction FAQ

Common questions about adu construction in San Francisco, CA.

Yes, you can build and rent an ADU in San Francisco without living on the property. California law removed the owner-occupancy requirement for ADUs effective January 1, 2024.

We build detached ADUs, attached additions, garage conversions, and basement conversions in San Francisco. The right type depends on your lot size, zoning district, and existing structure.

San Francisco does not set a single minimum lot size for ADUs. Eligibility depends on your specific zoning district and the details of your proposed project.

No replacement parking is required when you convert a garage to an ADU in San Francisco. This makes garage conversions a popular option for homeowners with limited yard space.

San Francisco ADUs must meet minimum size, ceiling height, natural light, ventilation, fire safety, and energy efficiency standards. Your project will go through building and energy inspections as part of the city approval process.

San Francisco now allows homeowners to sell newly built ADUs as separately deeded condominiums under an ordinance that took effect in 2025. This applies to single-family homes and small multi-unit buildings.

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What homeowners say.

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3 Google reviews

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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

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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