Office Vacancy at 21% Nationwide: CoStar Data Shows No Real Recovery Before 2028

The office market's long-promised recovery keeps getting pushed further into the future. CoStar, the leading commercial real estate analytics provider, released its Q1 2026 data in late April showing that 21% of all U.S. office space was vacant in the first quarter of the year—up from 17% in 2020 before the pandemic-era remote work transformation began.

Six years after COVID fundamentally changed where white-collar workers do their jobs, more than one in five square feet of American office space sits empty. And CoStar's revised forecast says the situation will not meaningfully improve until at least mid-2028—an admission that the "temporary disruption" narrative that the office real estate industry clung to for years is definitively over.

The Numbers That Aren't Recovering

CoStar's April 2026 forecast report delivered a carefully worded but damning assessment: "U.S. office vacancy is now forecasted to end 2026 roughly 10 basis points lower than previously anticipated, but should converge with earlier expectations by mid-2028."

Translation: we thought it would be better than this by now, it isn't, and it won't be until 2028 at the earliest. A 10-basis-point improvement in a 21% vacancy rate means vacancy falls from 21.0% to 20.9%—a rounding error in a market that, at its pre-pandemic peak, ran at approximately 12-13% vacancy.

In markets like Denver's suburban tech corridor—the stretch from the Denver Tech Center to Lone Tree that once hosted major tech and finance employers—vacancy in Q1 2026 ran between 19% and 21%. Axios's local analysis quoted a market expert who noted: "Everyone got back into the offices in a lot of the other markets, and they haven't in the Denver market as quickly."

The same pattern is visible across virtually every Sun Belt and Mountain West market that saw explosive growth in the 2010s driven by tech sector expansion. Those tech employers, who embraced remote work most aggressively during the pandemic, have been slowest to return to the office—and in many cases are now conducting their own workforce reductions through layoffs, further reducing the employee headcounts that would fill those spaces.

Why Vacancy Won't Normalize Before 2028

The persistence of elevated vacancy is not a mystery. Several structural forces are working against recovery:

Hybrid work is now the baseline, not a temporary accommodation. Major employers have settled into permanent hybrid arrangements—typically two to three days per week in office. This means that a company with 1,000 employees effectively needs space for 400-500 at any given time, not 1,000. Many companies have taken the opportunity of lease expirations to right-size their footprints dramatically. The new demand simply does not exist to absorb the empty space.

AI is reducing white-collar employment density. The wave of AI adoption that began in earnest in 2023-2025 has reduced the number of knowledge workers companies need to perform the same volume of work. Legal, accounting, software development, data analysis, customer service—each sector has seen meaningful headcount reduction driven by AI tools. Fewer workers means less office demand, even if every worker came back full-time.

The refinancing crisis is killing investment. With the 30-year Treasury at 5.2% and the 10-year at 4.67%, office building owners facing loan maturities are confronting refinancing costs that make most office buildings financially unviable as investment properties. The result is a market where:

Owners are reluctant to invest capital in improvements that would attract tenants
Distressed sales are occurring at 60-70 cents on the dollar or worse
Lenders are taking back keys rather than extending and pretending indefinitely
New buyers are essentially absent because the financing math doesn't work

Construction has collapsed. New office construction in the U.S. has essentially stopped in most markets. Permits are near post-financial-crisis lows. Cranes that once dotted downtown skylines building new towers have largely disappeared. While this is ultimately healthy—the market is not adding supply into an oversupply situation—it means there is no pipeline of modern, efficient space being built that might attract relocating tenants and create secondary demand for conversions.

The Conversion Mirage

Office-to-residential conversion has been promoted as the solution to high vacancy—turn empty offices into apartments in cities that desperately need housing. The concept is compelling, the execution is nearly impossible.

Most office buildings, particularly those built from the 1970s through the 1990s, have floor plates that are too deep for residential use (most bedrooms require natural light from an exterior window), HVAC systems designed for open-plan office configurations, plumbing chases in the wrong locations, and ceiling heights that don't accommodate residential code requirements. The cost of converting a mid-century office tower to residential typically exceeds the cost of new construction.

A handful of successful conversions—mostly in architecturally favorable early-20th-century buildings—have generated headlines, but they represent a small fraction of the vacant space that needs to be absorbed. The vast majority of empty office buildings will either need to be demolished, repurposed for uses that don't require residential conversion (data centers, light industrial, self-storage), or simply sit vacant until the debt structure collapses and the buildings change hands at distressed prices.

The 2028 Reckoning

CoStar's "mid-2028" timeline for vacancy normalization is premised on gradual absorption of excess space as leases expire and companies make decisions. It assumes no further deterioration in demand, no major recession that further contracts employment, and no acceleration in the trend toward smaller footprints.

Each of those assumptions is currently under threat. The Iran war's economic shock, rising unemployment risks, private credit defaults affecting CRE lenders, and 5.2% long-term yields all represent downside risks to the CoStar baseline.

The more likely path to office vacancy "normalization" may not be demand recovery—it may be the permanent removal of obsolete buildings from inventory through demolition, conversion to other uses, or complete abandonment. When 20-30% of office inventory disappears, vacancy rates on the remaining stock will look better. But that's not recovery. That's the market acknowledging a permanent structural change.

For investors still holding office real estate—banks with CRE loans, insurance companies with office mortgages, pension funds with real estate allocations—the 2028 timeline is a comfort that may not survive contact with the current macro environment. The reckoning for America's empty offices is not years away. It is actively underway.