Searching for your House’s History:Using Historic Fire Insurance Maps

The cover of the Sanborn map for Victoria B.C. for 1885

The Sanborn Map Publishing Company produced amazing fire Insurance maps across North America from 1867 to 1969. Surveyor D.A. Sanborn designed these specialized maps to assist fire insurance agents in determining the degree of hazard with particular properties.

They were terribly expensive to buy at the time – with a price of $ 50. in 1885 – so companies must have thought hard before agreeing to purchase them. However, these maps were the cutting edge information of their day, and they made it possible for fire insurance agents to assess potential danger to a structure without leaving their offices, simple by consulting the appropriate map.

Daniel Alfred Sanborn 1827-1883 Surveyor, founder of Sanborn Map Company

Carefully surveyed, and meticulously hand-drawn and coloured, the maps showed outlines of all the buildings, both commercial and residential, in an accurate manner, with appended notes as to the height of the building, observations on odd construction, and the use of specialized structures, such as theatres, churches and hospitals. Notes such as “steep hill” or “Cooperage” (a barrel making building) added to the insurance agent’s information.

By using colour, the maps indicated which material was used to construct the building. Pink for brick buildings, yellow for wood structures and blue for stone. Iron buildings were grey, and, for regional variation, adobe buildings were coloured olive.

For owners of old houses, and other interested researchers, these maps are invaluable, as they sometimes are the only record of what the buildings looked like in their early years – at least before Google maps happened on the scene!

Found today at archives and map libraries, and sometimes at old time insurance offices still, where they might be kept as curiosities, these treasuries of information can answer all sorts of questions about your house and surrounding structures.

The maps were regularly updated by pasting new drawings over redeveloped properties. Sometimes, shining a flashlight up through the paper can reveal the underlying drawings and the former configuration of the building in question.

This example shows the Episcopal Cathedral in Victoria, B.C. – a wood structure (yellow) – at top left. Three houses are just below. To the right is the brick (pink) Angela College, with wood (yellow) porches.

This section of a page of a Sanborn map shows St. Ann’s Academy prior to 1886, in Victoria B.C. St. Ann’s was a Catholic convent and boarding school for girls. The original 1871 building is shown in brick (pink) with a wooden recreation wing in yellow to the left. A small “4” on the brick wing indicates four stories in height, while the wooden recreation wing has a “1”, denoting a single storey structure. Three houses are to the south, across the street.

This example shows a street of several houses (marked “D” for Dwelling) Pasted updates can be seen by the lighter squares of paper. The small numbers (1; 1 1/2; or 2) indicate the number of stories. The small blue square is a stone garage on the street. A surprise is the note for a “Private Observatory” which a local resident remembered as being there in the 1930’s. The shape of each house indicates porches and bay windows.

This stone house (“D” for dwelling) is set on a “steep hill” as noted on the fire insurance map. The blue colouring indicates a stone building, with “wdws all sides” (windows all sides). It is 2 stories tall. A summer house was down the slope overlooking a tennis court at top right on the map. An ‘update square’ can be seen at lower left.

A number of wooden (yellow) buildings surrounding one brick (pink) building on a block. A fire insurance agent would look at the susceptibility of these wooden buildings so close together, in case a fire broke out. The building in the center of the block is marked “Cooperage”(barrel making).

We all owe a great debt to the historic Sanborn Company for recording the buildings of North America so meticulously. Sometimes the only record of changes or alterations to our Old Houses and their neighborhoods are found in these masterpieces of observation.

The terms “Sanborn” and “Sanborn Maps” are registered trademarks owned by The

Sanborn Library, LLC.