If Seattle Office Is 36% Empty, Why Can't My Client Find a Full Floor?

Downtown Seattle office vacancy reached 36.5 percent in Q1 2026, up from 33.0 percent a year earlier, the highest reading of any major US market (Cushman & Wakefield). Kidder Mathews, tracking multi-tenant buildings over 10,000 square feet, put Seattle Close-In at 28.0 percent for the same quarter. Whichever methodology you trust, the direction is the same and the word for it is glut.

A vacancy rate is a ratio across every building and every suite in a market. It answers one question: on average, how much space is empty. It does not answer the question a tenant actually asks, which is whether the specific thing they need exists. A growing tenant does not lease the average. They lease one contiguous block, in one building, that has the floor plate, the location, the parking, the condition, and the credit-worthy neighbors their business requires. In a 36 percent market that block can still be a short list, or a list of one.

So the market is bifurcated inside a single statistic. Downtown small-tenant and commodity Class B and C space is deeply oversupplied, and a tenant under the regional average lease of about 6,460 square feet (Newmark, Q1 2026) has genuine leverage and real optionality. The large, high-quality, well-leased block is a different asset in a different supply-and-demand balance, and it is tightening.

The Eastside is where the scarcity is visible. Downtown Bellevue full-floor availabilities dropped to 124 in Q2 2026, down 51 from the market's peak (The Registry). The pool of large blocks, especially move-in-ready floors in top-tier towers with views, has fallen roughly 15 percent since mid-2024 (2026 Eastside market reporting). Against that shrinking menu sits 2.4 million square feet of active tenant requirements, per CBRE's Bryan Oliver at the 2026 Eastside Real Estate Symposium, with Bellevue CBD gross rents above $80 a square foot. Kidder puts Eastside vacancy at 21.6 percent, a number that looks soft until you filter it for the floors an expanding AI or tech tenant will actually sign.

The Eastside AI corridor is the demand engine. OpenAI, Uber, and a roster of tech names have signed or expanded in Bellevue, and 2026 is on track to be the first year in a decade with no new Eastside office delivery. Demand rising into a menu that is not being restocked is the definition of a tightening block market, even while the regional vacancy headline stays ugly.

Downtown Seattle is the other speed. It genuinely favors tenants, asking rents drifted down year over year, and concessions are the real negotiating currency. The nuance for a broker: even downtown, the flight to quality means the small number of well-leased, amenitized Class A towers behave more like the Eastside than like the 36.5 percent headline. The glut is concentrated in the buildings nobody is fighting over.

Because the pipeline that would refill the top of the market was shut off years ago, and the bottom is being demolished. Phil Mobley, CoStar's national director of office analytics, laid out the supply math on America's Commercial Real Estate Show: "We've got a generationally low level of new supply getting started. The past six or eight quarters, it's been around 5 million square feet per quarter. And if you go back to the late 2010s, it was 15 million per quarter. It wasn't all that uncommon to see a quarter more like 18 or 20 million."

At the same time, obsolete space is coming out of inventory. Demolitions and conversions have been running above 8 million square feet a quarter nationally, and Mobley expects that to accelerate. That removal cleans up the vacancy rate slowly, but it does nothing to add the kind of space a growing tenant wants, and in Seattle the office-to-residential conversion incentive passed in 2025 points the least competitive downtown stock toward housing rather than back onto the leasing market.

Then there is the demand side that keeps the squeeze on the big blocks. Mobley again: "Lease sizes are smaller, on average, 15 or so percent than they were before the pandemic. We have seen a little bit of a lock-in effect with large occupiers. If you're looking for premium Class A space that's well-leased and you're looking for a lot of it, say 100,000 plus square feet, depending on what market you're in, there's not a lot of it left." A lock-in effect means the tenants sitting in the best large blocks are renewing rather than vacating, so those floors never hit the market to begin with.

It means the aggregate vacancy number is a trap, and reading it literally is the most expensive mistake a large-requirement client can make. The instinct in a 36 percent market is to wait, because waiting in a tenant's market usually pays. For a full-floor or large-block requirement in a tightening submarket, waiting can shrink the menu instead of improving the terms.

The leverage question is not what is the vacancy rate. It is how many buildings actually qualify for this requirement, and which direction that count is moving. On the Eastside, for a well-located full floor of quality space, that count is small and falling. A client who waits two quarters for a better market may find the same rent and two fewer options, and the two that left were the ones with the right floor plate.

Downtown, the calculus flips for most tenants. If your client needs 5,000 square feet of good space and can live with a value-add build-out, the glut is real, the concessions are real, and patience is rewarded. The discipline is knowing which market your specific client is standing in before you advise them to wait or move.

Four moves, none of which require buying anything.

Count qualified blocks per live requirement, not vacancy points. For each active client, maintain the actual short list of buildings that fit their floor plate, size, location, and credit needs, and track how that count changes quarter over quarter. That number, not the market vacancy rate, is your client's real leverage reading.

Separate your pipeline into two markets. Tag each requirement as glut-side (small or commodity, patience pays) or scarcity-side (large, quality, block-constrained, the clock is running). The advice you give should follow the tag, not the headline.

Pull the submarket block trend, not just the vacancy trend. A vacancy rate that is flat or rising can sit on top of a large-block count that is falling. Ask your research contacts, or your data, for full-floor and large-contiguous availability counts by submarket and watch the direction.

Get ahead of the renewal lock-in. If a scarcity-side client is even 18 months from expiration, the tour of qualified buildings should happen now, because the best blocks are being renewed off-market by the tenants already in them.

The honest counter is that downtown Seattle is genuinely, structurally oversupplied, and most tenants are downtown-market tenants, so for the majority of deals the 36.5 percent headline is not a trap, it is the correct read, and patience is the right advice. The scarcity story is concentrated at two narrow edges, the large end of the size curve and the top of the quality curve, and it is easy to over-generalize a real Eastside squeeze into a false region-wide urgency that pressures clients into signing early. That would be doing the landlord's job.

There is also a timing caveat. Supply removal through demolition and conversion is a slow multi-year drift, not a cliff, and a demand shock could reopen the large-block market quickly. Mobley himself flags the wild card: if AI lets firms grow output with fewer people, "that could dampen demand for additional space," which would loosen exactly the Eastside blocks that look tight today.

The resolution is not to pick a side of the vacancy number. It is to stop leading with the number at all. Advise the requirement in front of you, count the blocks that actually fit it, and let that count, not a market-wide average, set the urgency.