How Much Does a Room Addition Cost in San Francisco?
Room addition costs in San Francisco
San Francisco permits show a median estimated construction cost of $362,500 for room additions on one- and two-family homes, last 12 months.
San Francisco at a glance
- Median estimated construction cost, room additions on one- and two-family homes, last 12 months
- $362,500
- Issued room addition permits, all property types, last 12 months
- 112 permits
- Median days from filing to issue, room additions on one- and two-family homes, last 12 months
- 197 days
San Francisco Department of Building Inspection, Building Permits (DataSF) · data as of
- Numbers from SF DBI public records
- Up to three local contractors, never a long list
- Free, no obligation
San Francisco room addition permit figures
Median estimated construction cost in San Francisco
| Project | Figure | Range on a shared scale |
|---|---|---|
| Median estimated construction cost, room additions on one- and two-family homesA median estimated construction cost written on permit applications. It is what applicants expected the permitted work to cost, not the full project cost or a quote. | $362,500 |
Bars share one scale, from $0 to $362,500.
Estimated cost on the permit application for room additions on one- and two-family homes in San Francisco, over the last 12 months. This is not a contract price. Get an estimate for your home to learn your own cost.
Planning your project
Over the last 12 months, the median estimated construction cost on San Francisco room addition permits for one- and two-family homes was $362,500. That figure is what applicants expected the permitted work to cost. It is not a contract price or a quote for your home.
What the permit figure leaves out
The real project cost is often higher. Design, materials, finishes, work that is not on the permit, and the condition of your home all add to the total. Two room additions with similar floor plans can still cost very different amounts.
Get an estimate for your home
The most reliable way to know your cost is an estimate based on your own plans and your home. Describe your project to a local builder and ask for a written estimate.
Room addition cost questions
Is the permit's estimated cost the real cost of a room addition?
No. The permit figure is the median estimated construction cost of $362,500 written on permit applications for room additions on one- and two-family homes over the last 12 months. It is what the applicant expected the work to cost, not a contract price. Your real cost can be higher.
What drives the price of a room addition in San Francisco?
Design, materials, finishes, the size and layout of the work, work that is not on the permit, and the condition of the existing home. Each project is different, so ask for an estimate based on your own plans.
Why do estimates for the same room addition differ?
Builders price labor, materials and scope differently, and plans often change as a project moves forward. An estimate based on detailed plans is usually closer to the final cost than a rough guess.
How do I get a reliable number for my project?
Share your plans, site conditions and finish choices with a local builder and ask for a written estimate. You can also check any contractor's license status with the CSLB (Contractors State License Board).
Does a room addition in San Francisco need a permit?
Check with the San Francisco Department of Building Inspection or your builder before you start, since the rules depend on your project. Over the last 12 months, the department recorded 112 permits for issued room additions across all property types in San Francisco.
How long does the permit process take in San Francisco?
The median time from filing to issue was 197 days for room addition permits on one- and two-family homes in San Francisco over the last 12 months. Your own timeline will depend on your project.
Recent work by a contractor in our network
Photos from the contractor's own projects, used with permission. Captions name the type of work.
Whole-home remodel, exterior 
Kitchen, whole-home remodel 
Addition / ADU interior 
Addition / ADU interior 
Whole-home remodel 
Whole-home remodel
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