Anyone have experience with Sanborn Fire Insurance maps?

ChrisJ

I got a hold of a set of Sanborn maps for the area my house is in.  One thing has me confused.  What are the chances of these maps being inaccurate as far as how many floors are in a home?



Dates I have are 1892, 1897, 1902, 1909, 1914, 1924, 1941, 1961.  And this is all that were available for the area.



My house is in a business area which I guess is the only reason I can even get maps of it.  1892, 1897, 1902, 1909 seem accurate.  1914 also seems accurate for the most as does 1924.  However 1941 and 1961 appear to be copies of 1924 with a few updates on other buildings and it shows my house only being 1 story where its currently two stories.  Reason I find this hard to believe is the room on the 2nd floor it claims didn't exist in 1961 has a properly sized 1920s Kohler radiator which matches all others in the house.  Not to mention the walls are all plaster.



Thank you for your time.

Bob Vennerbeck

They're all over the map...

I've pored over the Sanborn maps for Providence, RI, and been astonished at the detailed data they collected and collated - but the accuracy seems to be 'all over the map' for areas that I have some real familiarity with - then I consider what might have been the process - a legion of guys (almost certainly) with clipboards and not quite enough sharp pencils, hoofing all over town, not being particularly welcome in some places, and where did they stop for lunch, and for how long? The results are still pretty amazing!



http://www.loc.gov/rr/geogmap/sanborn/san4a1.html



Vbob