Where are the floorplans for your home? That’s a good question. Many homes in SF as well as other parts of the Bay Area do not have plans on file due to the age of the home. If you think back 80 years ago, there were no photo copiers and every copy of plans had to be hand drawn so asking someone to submit a copy was a burden. Today we expect these things with a click, but it just wasn’t required for residential construction until at least the 1960s anywhere! You can view the plans at the SF Records Management Division without all signing anything but you can’t have a copy without requesting them as the owner AND getting the architect’s permission if there was one. It’s a pain but it’s to protect your security and the copyright of the professional who drew the drawings. (Strange idea they own the work product even though they were paid to create it? But I’ve been told that’s the way it works.). In cases where the design professional has passed away, you can get the drawings with just the current owner’s signature.
The easy to access electronic records at www.sfdbi.org go back to about 1995, but there are permits on file that are older, including the images of the actual permits. It can be quite interesting to decode the old and often very fancy handwriting on them.
I think it’s a good idea to go get a complete permit history for your home just to have it as well as copies of any plans on file.
Here is a link to SFDBI permit tracking: https://dbiweb02.sfgov.org/dbipts/
Here is a link to SFDBI records department: https://sfdbi.org/RMD
Many records regarding your home can be found here on the Property Information Map: https://sfplanninggis.org/pim/
For homes older than 1900, sometimes it is useful to go to the water department, which only the owner can do, and get a copy of the original water connection record. You used to have to go in person but now you might be able to use this system, and I’m testing it right now: https://sanfrancisco.nextrequest.com/requests/new
Here is a great overall “how to” on researching older homes from the SF Public Library: https://sfpl.org/locations/main-library/sf-history-center/how-research-san-francisco-building/how-old-it-who-built