After last week’s article about the historical reasons that houses in St. Louis might fall over, I was having a conversation with a friend and local business owner about the oft-contradictory sources of information to determine what year buildings were constructed.

St. Louis, of course, celebrated its 250th anniversary back in 2014, but no house in the city comes close to being that old. Credit for the city's oldest house rests with the Baron de Hodiamont House, which was built in 1829 in what's today the West End neighborhood, just several hundred yards from the county line. And depending on which historian you speak with, semantics come into play as well. Take the Bissell Mansion, which gets the distinction of being the oldest brick house in St. Louis, dating to 1831. But those are the superlatives in St. Louis house dating with considerable documentation.

So how does the average homeowner discover the age of a house in the city?

First of all, homeowners should have a general idea of when their neighborhood was first settled or developed. While it's never quite so simple and there are obvious exceptions, the city was just barely developed out to Jefferson Avenue by the time of the Civil War (hence the location of the fortifications along a line roughly along that thoroughfare).

In addition to then-independent towns such as Baden and Carondelet, neighborhoods such as Lafayette Square, Benton Park, Old North, and Hyde Park rapidly developed after the Civil War, and, by the World’s Fair in 1904, the city was just expanding to Forest Park. Neighborhoods between Kingshighway and the city limits developed in the decades between the World’s Fair and 1920, and most of St. Louis was complete by the 1930s. (A notable exception is the St. Louis Hills area, with its distinctive gingerbread houses, which were still being built in the 1940s and '50s.)

After getting a general idea of when the neighborhood was built, a homeowner should next consult Geo St. Louis, the city’s property-information website, which provides a wealth of data about the buildings on a given property. Clicking on the “Building Information” tab on the right will provide the date of construction in the city’s database.

But now is the time to be careful! The older the building, the more likely that the date will be inaccurate. For example, take the aforementioned Hodiamont House. While the home was indeed built in 1829, it received a substantial second-story Carpenter Gothic-style addition in 1890. Consequently, the former is the date listed on Geo St. Louis. Likewise, many houses received indoor plumbing or other additions in the 1950s, so later dates of “construction" may be listed. I've also begun to suspect that because building permits were not common before the Civil War here, city employees at one point simply assigned an 1883–1887 construction date to buildings with unknown dates of construction.

Why do I suspect that? Compton and Dry’s 1876 View of St. Louis, another invaluable resource for homeowners whose houses are located east of Jefferson Avenue. With careful examination of the plates, scanned with glorious precision by the Library of Congress, homeowners can see whether their houses were already built in 1875, when the Compton and Dry firm surveyed the city to create a bird’s-eye view of St. Louis. Many houses that already appear in Compton and Dry have dates listing construction in the 1880s, so I know that many dates of construction listed online are incorrect. If you can find your house on Compton and Dry, then you're very lucky and own a very special house, as most buildings still standing in St. Louis were built many years after 1875, and most of the houses in that famous view are now gone. Remember: Many streets have been renamed since 1875, so use landmarks to get your bearings.

It's worth noting, however, that the block number on Geo St. Louis should always be accurate. Write down that block number, and head to Room One at City Hall. There, the staff can pull microfiche with records of the buildings permits (if they exist) for the buildings on your block. It might take a while and you'll need to pay a small fee to make a copy, but if a record of your building permit exists, it should be there. The building permit record on microfiche will provide a definitive answer about the year that your house was built. If you're lucky, it will list the name of the building contractor who originally pulled the permit. If you’re really lucky, you will discover the architect, though that's only likely if you own a house in the Central West End or another prominent area, such as a private street in a subdivision designed by Julius Pitzman.

Finally, homeowners should visit the Missouri History Museum’s Library and Research Center on Skinker, where the staff can help look up the address of your house and see whether, by some chance, it was photographed in the past. I've had considerable luck with the work of William Swekosky, who photographed much of the city at the turn of the 20th Century. (Note: Simply going to Google Books and searching for your address and “St. Louis” can also bring up helpful results.)

Again, the more prominent the former residents of your house, the more likely you'll find something interesting about what happened on your piece of historic St. Louis during the past 200 years.