San Francisco Supervisors' Contact Information
Supervisors are local representatives for each neighborhood in San Francisco, and have a large amount of influence over what housing does or doesn't get built, and where. You can find the email addresses and phone numbers for San Francisco supervisors on the San Francisco Board of Supervisors website.
If you aren't sure who the supervisor is for your neighborhood, you can find out by searching for your address using the San Francisco Property Information Map lookup tool from the SF Planning Department.
San Francisco Zoning Map
In San Francisco, what you can build and where depends on a complex system of zoning rules and height restrictions. To see what the rules are in each place, you can use this interactive map.