If you're a professional architect, civil engineer, or urban planner you probably already know about this, otherwise be prepared to learn how you can quickly find out a variety of interesting details about most privately owned houses and buildings in the United States, or at least in all cities of medium size and up.
In my own county (Los Angeles), the Tax Assessor's website makes this information freely available for retrieval by street number, intersection, or AIN number, but from what I have seen this is atypical. However, even if the county in question does not do this, you can still get this information from the City-Data.com website, which also hosts a huge set of forums about individual cities. (Those forums deal mainly with quality of life issues, as in "Should I move there?" etc.).
Here's a sample of their data using 55 Wall Street, NYC as an example:
55 Wall Street
Manhattan, NY 10005
Find on map >>
Assessments for fiscal year: 2011/2012
Tax class: Apartments
Lot frontage: 197 feet
Lot depth: 171 feet
Land size: 31,469 square feet
Irregularly shaped lot: yes
Building frontage: 204 feet
Building depth: 171 feet
Living area: 274,516 square feet
Irregularly shaped building: no
The number of stories for the building: 9.0
The number of buildings on the property: 1
The year the building was built: 1836
Read more: http://www.city-data.com/ny-properti...#ixzz23qAr7oDS
Note the build date, 1836! I don't believe you can get this information from the County Of New York unless you pay for it.
As you can see, there is also quite a bit of additional data provided, such as square footage, living space, and so on. Surprisingly, it also gives the names of the property owners, corporations or individuals as the case may be--and the L.A. county website does not
do this. While this is presumably public information, I have mixed feelings about it being so readily available. To be honest, I do my best to avoid reading that part of the display, or at least to forget about it as far as possible.
To search this data, it's best to use Google rather than try to search within the site. To retrieve the above sample data, I typed the following into the Google search box:
55 Wall Street New York, NY property valuation site:city-data.com
What comes back is usually the information as above for several properties in that block or along that section of the street. You just have to scroll down to reach the property in question.
As you probably guessed, the tag site:city-data.com
tells Google to limit the search to the website in question, and is often much, much easier than trying to do so using the website's own search capability--as in this case. Although this doesn't change the result as far as Google is concerned, it's best to type the address first followed by site:city-data.com. This makes it easy to backspace over the address and type in a different one, after back-paging to the Google search page. The data is free from bloat or Flash-player requirements, so you can do this on a smartphone as well as a computer. If you have a smartphone with a data plan you can actually get this data on the to, as you happen to pass by a building or house that piques your interest.
Not every interesting building can be researched this way, government buildings generally do not appear. You also might not find data on public school buildings or historical monuments owned by federal or state park services, particularly when multiple historic buildings have been included in a state-owned historical park, like Olvera Street and the surrounding area.