OREB says Ottawa prices rose 1%. Teranet says they fell 2%.

Two reports, same month, opposite signs

Two credible sources published Ottawa price data in the last six weeks and they do not agree. OREB's own August release has the benchmark price up 1.0 percent from a year ago. The Teranet-National Bank House Price Index, a completely separate measure built from land registry data, has Ottawa-Gatineau down 2.16 percent over the same twelve months. Same city, the same general stretch of calendar, and the two numbers are moving in opposite directions.

Both are legitimate. Neither is lying to you. They are measuring different things in different ways, and once you see how, the disagreement stops being confusing and starts being useful.

What OREB's own numbers say

OREB's August MLS Home Price Index benchmark sits at $637,700, up 0.6 percent from July and up 1.0 percent from a year ago. Run that year over year percentage backward and the implied August 2025 value is about $631,400. OREB's own story is a house that gained roughly $6,300 over the last twelve months.

Break the composite apart by property type and the picture gets less uniform. The single-family benchmark is $726,700, up 2.2 percent year over year. The townhouse benchmark is $547,300, down 4.0 percent. The apartment benchmark is $392,900, down 3.6 percent. The composite is up because single-family carries the most weight in the blend, not because every segment moved the same way.

What the Teranet-National Bank index says

Teranet is a different animal entirely. It uses the repeat sales method, tracking the same physical properties across multiple registered transactions over time, sourced from public land registries rather than MLS boards. Its Ottawa-Gatineau reading for August fell 0.33 percent from July, seasonally adjusted that is a 0.53 percent drop, and is down 2.16 percent from a year earlier. That year over year decline deepened from July's reading of down 1.58 percent, so the trend moved further into negative territory in a single month, not less. The index also sits 3.98 percent below its own June 2022 peak.

Apply Teranet's year over year rate to the same $637,700 starting point OREB uses and the implied year ago value comes out around $651,800, meaning that same house lost about $14,100 by Teranet's read. Put OREB's plus $6,300 next to Teranet's minus $14,100 and the two reports disagree on the same theoretical house by roughly $20,400 in a single year.

Three real reasons they disagree

The first reason is geography, and it is more literal than it sounds. OREB's board area covers Ottawa and the surrounding Ontario communities it serves. Teranet's index is built for the Ottawa-Gatineau census metropolitan area, which blends in resale activity from Gatineau, Quebec, a different province with its own economy, its own construction pipeline and its own price dynamics that have nothing to do with a semi in Barrhaven.

The second is methodology. OREB's benchmark models a fixed, typical home with a set bundle of characteristics and estimates what that model home would sell for each month. Teranet only counts properties that have sold more than once and compares the two sale prices directly. Ottawa does not generate a huge number of repeat sales in any given month, which makes a repeat sales index more sensitive to which specific properties happened to trade and resell, especially over a short window.

The third is timing. Teranet's numbers come from land registry filings, meaning a property shows up in August's reading when its sale is registered on closing, not when the deal was struck. In Ontario, 30 to 90 days commonly separate an accepted offer from closing. OREB counts a sale the month it is reported sold to MLS, much closer to the day of the agreement. Teranet's August number may be reflecting offers written back in June or July, against a thinner inventory picture than the one buyers are working with today.

The warning was already inside OREB's own release

I wrote in August that Ottawa's own average, median and benchmark numbers disagree with each other inside a single OREB release, and that the honest fix is to read your own property type's benchmark instead of the composite. Townhouse and apartment benchmarks were already negative year over year before Teranet's number ever entered the conversation. A citywide composite that is barely positive is being held up almost entirely by single-family homes.

That matters here because it tells you the composite was already fragile before you layer a second, independent index on top of it that is reading the broader region as negative. Two thirds of OREB's own property types were already softer than the headline, in the same month I wrote that Ottawa is starting plenty of housing but almost none of it for owners. Teranet is not contradicting either story so much as extending them across the river and back a month or two in time.

Which number to actually use

Use OREB's benchmark for your specific property type as the starting point, because it is the one built from actual Ottawa board transactions and it updates on a sale date rather than a closing date. Treat Teranet as a check on direction and momentum rather than a substitute, particularly given how much active inventory is sitting unsold right now. Watch whether the two keep drifting apart or start converging over the next couple of readings. If Teranet's Ottawa-Gatineau number keeps deepening while OREB's composite holds flat, that is the record supply working its way through the system on a lag, and I would rather sellers see it in a repeat sales index first than in their own showings three months from now.

Trying to figure out which of these two stories actually applies to your street and your property type? That is exactly the kind of question a fifteen minute conversation answers better than either index on its own. Call 613-262-6545, email fil@613realtor.ca, or see what's actually listed right now before you anchor on either headline.