Ottawa office Q3: CBRE sees 10 bps, Altus sees 110

Two reports, one quarter, two stories

Two brokerage reports on Ottawa office space landed within two weeks of each other. CBRE published on October 8 and Altus Group updated its page on October 21. Both cover Q3 2026. Both say the market improved. They do not agree on how much, and the gap is big enough that you should know which number you are quoting.

CBRE has vacancy at 14.9%, down 10 basis points from 15.0% in Q2. Altus has availability at 13.4%, down from 14.5% in Q2. That is a 110 basis point drop. Same city, same three months, and one report says the market barely moved while the other says it fell by more than a point.

The absorption gap is bigger

Absorption is the space tenants took minus the space they gave back. Here is the same quarter from each side.

CBRE: negative 120,254 sf in Q2, positive 28,000 sf in Q3. That is a swing of 148,254 sf (28,000 + 120,254).

Altus: positive 234,000 sf in Q3, which it describes as the first positive quarter after five negative ones.

So Altus counted 8.4 times as much absorption as CBRE (234,000 / 28,000). The difference is 206,000 sf. Against the 40.6 million sf CBRE says it tracks, that is about half a percentage point of the market (206,000 / 40,630,578 = 0.51%). Altus likely tracks a different set of buildings, so treat that as a rough size, not a reconciliation.

Two different yardsticks

Vacancy and availability are not the same thing. Vacancy is space that is empty. Availability is space that is on the market, which also includes space still occupied by a tenant who has given notice or is subleasing. CBRE's own Q2 report shows the difference in one place: vacancy 15.0%, availability 16.1%.

Look at the levels and they line up less than you would think. In Q2, Altus availability (14.5%) sat 160 basis points below CBRE availability (16.1%). In Q3, Altus availability (13.4%) sits 150 basis points below CBRE vacancy (14.9%), and CBRE availability for Q3 is not in the figures I could read. The two series were never the same size, which is fine. What matters is the quarterly move.

Here is a check on the Altus number. If its inventory is about the size of CBRE's, a 110 basis point drop is roughly 447,000 sf (1.1% x 40,630,578). Altus reports 234,000 sf of absorption, which explains about 0.58 points (234,000 / 40,630,578). That leaves roughly half the drop unexplained by absorption. My read, and it is a hypothesis, is that space was pulled off the market without a tenant moving in: leases signed for later occupancy, landlords withdrawing floors, or buildings leaving the stock for conversion. I can't confirm any of that from the page.

Where both reports agree

The tenants taking space are not the ones giving it back. CBRE split its Q3 number: Class A absorbed 112,000 sf and everything else lost 84,000 sf (28,000 - 112,000). Altus says private-sector demand for Class A is supported by the expanded multi-day office attendance directives, while federal space rationalization and property surrenders pushed its availability up 50 basis points year over year to 13.4%.

Back out the year-ago level and Altus availability was about 12.9% in Q3 2025 and 12.4% in Q2 2025 (14.5% - 2.1). So 13.4% is back inside the 12% to 14% range the market held for three years, but it is still above where it stood a year ago. That is a recovery from a bad quarter, not a return to the old normal.

Re-litigating my October 10 post

In that scorecard I used CBRE's 14.9% to show that a 2024 forecast of under 10% vacancy by 2026 or 2027 was nowhere close. Altus's 13.4% does not rescue the forecast. Even on the friendlier yardstick, you are 340 basis points from 10%. It does change the tone. The Q2 picture was five quarters of negative absorption with no relief in sight, and now one report says that streak is over and the other says it has at least stopped getting worse.

What I would do with it

If you are a tenant negotiating a renewal, do not let the landlord's broker pick the report. Bring both. A landlord quoting CBRE's 14.9% has a weaker story than one quoting Altus's drop, and vice versa. The space you are looking at matters more than either: conversion candidates and non-Class A floors are where CBRE's negative 84,000 sf lives.

If you own a small office building outside the core, do not read the Altus number as a sign the floor is in. One quarter of positive absorption after five negative ones is a data point, not a trend.

I sell houses and commercial property. I'm not a lease lawyer or a tax adviser, so take any lease clause or capital gains question to the right professional first.

What I will check next

Here is the bet. When Altus publishes Q4 2026, likely in January, Ottawa availability will land between 12.9% and 13.9%, and absorption will be positive again. If it jumps back above 14%, Q3 was a one-off and CBRE's flat read was the right one. I'll also compare it with CBRE's Q4 vacancy against the 14.9% from my October 10 bet.

Thinking about leasing, renewing or buying an office or small commercial space in Ottawa? Call me at 613-262-6545 or write fil@613realtor.ca. I'll tell you what the space is actually worth to you, not what a headline says.