One of the most frequently asked questions by a homebuyer is, “How can I determine the age of the home I would like to purchase?” Unfortunately, this is one of the more difficult tasks a homebuyer has. Over the years, houses are given facelifts through renovation, repair and replacement which can often mask deterioration hidden beneath the surface. Over the years, we’ve worked with many home inspectors and they have some tricks for figuring out the age of a house.
In newer subdivisions dates can be picked up from manhole covers, sidewalks, and curbs. This will give you an idea of when the subdivision was built, but this obviously doesn’t work in older neighborhoods.

Thermal pane windows tend to have a metal strip which separates the two panes of glass. On that metal strip, you will often find the manufacturer’s name, a CMHC number, and the date of manufacture. Again, this information must be used carefully. It will tell you the age of the window, but not necessarily the age of the house. Check several windows. If they are all the same, you have just figured out how old the house is or the date when all of the windows were upgraded.

On houses built within the last 25-30 years, you will often find a sticker on the outside of the electrical panel indicating the possession date. The Ontario New Home Warranty Program placed these stickers on the electrical panel so that the warranty period could easily be established. If you can be sure that the furnace or the water heater is original, the gas inspection sticker on either of these appliances is a good indication of the age of the house.

Interestingly, the easiest place to pick up a date is off a toilet. Porcelain plumbing fixtures usually have a manufacture date stamped into them. If you remove the lid from the tank, the date will often be stamped on the underside of the lid and also inside the tank near the water line. The date is usually on the right hand side of the rear portion of the tank when you are facing the toilet. The date inside the tank is more reliable than the date on the lid because sometimes lids get broken and replaced. Again, you must look for other clues to convince yourself that the toilet is an original one. Otherwise, you have only established the date when the bathroom was renovated.

Certain building materials can also provide clues about the age of a house. With the exception of custom built houses, most houses built with concrete block foundations are pre-1970. Most subdivision houses built in the 70’s or newer have poured concrete foundations. Most brick houses in Ontario were solid masonry construction until the late 1960’s. Most brick houses built after 1970 were brick veneer construction. Furthermore, if you stand in an unfinished basement and look up at the subflooring, you will find that most houses before 1965 used plank subflooring. After 1965, most houses had plywood subflooring, that is, until the early 1980’s, when waferboard subflooring became popular with builders!

Aluminum wiring began to be used residentially in about 1965, however, it didn’t really catch on until about 1970. When was it banned? It never was banned. However, it received so much bad press, that aluminum wiring stopped being used in houses around 1978. To this day, aluminum wiring is still used to bring power into the house from the street!

As you are probably aware, knob and tube electrical wiring makes insurance companies cringe. Knob and tube wiring was superseded by conventional modern wiring in the late 1940’s. Even though wiring looked modern through the 1950’s, it was not until 1960 that modern wiring contained a ground wire. Therefore, houses built before 1960 have two prong outlets as opposed to modern electrical outlets which are designed for three prong plugs.

Prior to 1950, supply plumbing was galvanized steel. Houses with galvanized steel supply plumbing also tended to have waste plumbing made from cast iron. In about 1955, waste plumbing was more likely to be copper than cast iron. In the late 1960’s, the price of copper went through the roof and, as a result, waste plumbing very quickly became plastic.

Finally, older houses have plaster on the walls and ceilings, whereas new houses are built with drywall. When did the change occur? While there was no magic day when plasterers quit and drywallers started, most houses built before 1960 were plaster, and most houses built after were drywall.

Dating houses can be helpful for a number of reasons like estimating when you’ll need to invest in a new furnace or roof material; for example, the type of furnaces installed 20-25 years ago have a life expectancy of 20-25 years. Therefore, most houses built in the early 1990’s have a new furnace or will need one shortly.

We hope this helps out in your home buying adventure, and remember, it’s always best to consult with a trained Home Inspector before committing to a home purchase.