Realtors can help you best. Some might have their websites with IDX feedback - so you can also search yourself, if you are an active type...Zillow.com is also nice to get some idea (it's far from perfect on their values) - but the trends are shown pretty well.
Hope this helps,
CDPE (Certified Distressed Property Expert)
Beachfront Realty, Inc.
Hope this helps!
For specific data, email me the property parameters (bedrooms, baths, sqft,...) so I can send you useful comps. If you wish, include your property address and I'll provide radius comps that hold more weight.
Oggi Kashi - 415.690.3792 direct
Broker Associate, Paragon Real Estate Group CA DRE 01844627
All data from sources deemed reliable but subject to errors and omissions, and not warranted.
Perhaps I can help you with that. I'm assuming the property is in San Francisco County. The County Tax Assessors office looks at comparable properties the same that real estate agents do. It's not so much a question of zip codes as it is comparables sales (actual sales of specific properties which have closed escrow during the period in question.
Feel free to contact me if you have further questions.