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
ADU Construction in San Francisco, CA
HMM GC Inc. builds ADUs for San Francisco homeowners looking to add livable space to their property.
- 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
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
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Real Estate Expertise
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FAQ
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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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