Ottawa detached sells 16.8% over benchmark, down from 20.4%

Two prices for the same house

OREB publishes two numbers that sound like they should agree. One is the average sale price, which is what actually changed hands. The other is the HPI benchmark, which is the price of a fixed, typical home in each segment, so it ignores which houses happened to sell that month. When they move apart, the gap is telling you something about what sold, not what homes are worth.

September's release has a clean example of that. I ran the numbers by segment, because the citywide figures hide it.

The method, so you can redo it

For each segment I divided the September 2026 average sale price by the September 2026 benchmark. Then I backed out last September's average and benchmark from OREB's published year over year changes (price now divided by 1 plus the change) and did the same division. The ratio is the premium sold homes carried over the benchmark home.

One caution up front. OREB rounds those changes to a tenth of a percent, so the 2025 figures are reconstructions, good to roughly half a point on the ratio. I'll only lean on gaps that are bigger than that.

Detached: buyers bought less house

The September average for single family was $823,449, down 3.1%. The benchmark was $705,100, down 0.1%. That is a ratio of 1.168, so sold homes averaged 16.8% above the benchmark home, a gap of $118,349.

A year ago: $823,449 divided by 0.969 is about $849,800 for the average, and $705,100 divided by 0.999 is about $705,800 for the benchmark. Ratio 1.204. A 20.4% premium and a gap of about $143,987.

So the premium fell 3.6 points, roughly $25,600 of average sale price. The typical detached home hardly changed in value. What sold changed. The average dropped about three percent while the benchmark held, which is what you see when the mix tilts toward smaller, older or further out houses and away from the big ones.

I can't tell you from this data which of those it was. I can tell you that the headline "detached average down 3.1%" is mostly a statement about which houses sold, and only slightly about price.

Apartments: the opposite problem

Apartment average sale price was $431,645, up 0.9%. Apartment benchmark was $380,800, down 6.1%. If you only read the averages, apartments look stable. They are not.

Ratio now: 431,645 divided by 380,800 is 1.134, a 13.4% premium. A year ago: about $427,800 divided by about $405,500 is 1.055, a 5.5% premium. The gap went from about $22,300 to about $50,800.

That is a 7.9 point swing in a year, more than double the detached move and far outside my rounding error. Apartment sales fell 24.8% year over year, from roughly 161 to 121. OREB doesn't say which units dropped out, but an average that rises while the benchmark falls 6.1% is consistent with the cheaper end of the market going quiet and a richer slice, newer or bigger units, doing the selling.

If you own a typical older condo, the average sale price tells you almost nothing about your unit. The benchmark is closer. I made a similar point about two price indexes that disagree, and September is the same lesson inside a single source.

Townhouses: the control group

Townhouse average was $543,337, down 2.2%. Benchmark was $546,500, down 2.2%. Ratio 0.994. Last year, about $555,600 over about $558,800, also 0.994.

The two measures moved by the same amount and the ratio did not budge at all. That makes townhouses a useful control. When mix doesn't shift, average and benchmark agree. So the detached and apartment gaps are not an artifact of my method.

It also fits what I found when I compared August to 2016 by segment. Townhouses are the segment where the price is falling as a whole, not where the sales mix is wobbling.

What this means if you're selling or buying

If you are selling a detached house, don't price off the citywide average. A 16.8% premium to benchmark is the average of everything that sold, including large lots and big renovated homes. Your comparison is the specific houses that sold near yours, which is what a sold versus quit analysis is for.

If you are buying a condo and an agent quotes you the average, ask for the benchmark and for the actual sold comparables in the building. A 13.4% premium over benchmark means the average is describing a different kind of unit than the one you're looking at.

I sell houses. I don't give mortgage, legal or tax advice, and a benchmark is not an appraisal. A lender's appraiser or a licensed appraiser values your actual property.

A marker for this week

OREB's October release should land in the next few days. I won't guess its numbers. Here is what I'll score: if the detached premium to benchmark snaps back above 20%, my mix story was wrong and September was noise. If it stays under 18%, buyers are still buying smaller. I'll post the result.

If you want to know where your own property sits against the benchmark and the houses that actually sold around you, call or text me at 613-262-6545 or email fil@613realtor.ca. I'd rather show you the comps than quote you an average.