What are Sanborn Fire Maps?
Sanborn Maps are the best resource you can have for researching an old building.
Once you start looking at them you will most definitely be addicted for they will provide the best information you can find about the layout of the exterior of your home.
These maps are second maybe even better than a historic photograph.
Sanborn Maps were designed to assist fire insurance agents in determining the degree of hazard with particular properties starting in 1869 and continued through the 1960’s in some areas.
They were not used in rural areas and seldom on the outskirts of town.
The maps show an outline of residential houses, commercial buildings, and even factories. It shows which section had one floor, two floors etc. The roofing and construction material, if the building has gas or electric lighting. The location of a barn or auto garage. Most important a dotted line outlining the porches on the house.
- 301 Main Street
- 2 story wood frame house.
- wood single roof
- full front porch shown with dotted lines.
- Bay on side and rear.
- 1 story attached mud room in rear.
- 301 Main Street.
- House is now 2 1/2 floors.
- Wood shingle roof but porch roof is tin.
- House entrance was changed a new bay was added on each side and a rear side porch.
- Outhouse in rear.
- House number is now 30 Main Street.
- All else seems the same. This house was later demolished and is now the commercial area of Main Street.
Some towns had them produced every several years therefore you can see the evolution of the building you are researching. A house may be small in 1895 but you may then see that a rear porch was removed and an addition was built in 1910. Later, the front porch may have changed to become larger in 1915. A garage added when the family bought their first car in 1925. You just can’t get this information anywhere else.
Where to Find Sanborn Fire Maps
You can check with your local historical society or your town hall which may have the original books although not in great condition. This information should be in digital form at a County library or a College library. You may also be able to get them online. https://www.oldhouseonline.com/repairs-and-how-to/where-to-find-sanborn-maps Note that not all maps are available online. The more recent may need to be viewed in person.
If you are from New Jersey, Princeton University has them online and available to the public.