A meaningful share of the office buyers in a reset market are not investors at all. They are businesses, watching prices fall toward the point where owning the building beats renting space in it, and the owner-user purchase is its own discipline, related to investment underwriting but not identical, with its own characteristic mistakes.
The core comparison is occupancy cost against rent alternative, run honestly on both sides. On the ownership side: debt service, operating costs the landlord used to absorb, reserves for the roof and systems that are now yours, and the management attention a building quietly consumes. On the rent side: not your current rent, but what you would actually pay in this market with today's concessions, which in 2026 is frequently less than the lease you signed years ago. Owner-user math done against a stale rent number flatters ownership; done against the market, it still often wins right now, which is why the moment is real, but the margin deserves to be measured rather than assumed.
The characteristic mistake is letting the business case excuse the real estate case. A building can be a fine home for the company and a mediocre asset, and the two facts do not cancel: someday the business moves, shrinks, sells, or simply changes, and on that day the building gets priced by investors who never cared where your team sat. The discipline is to underwrite the building as an investor would, rollover economics on the suites you do not occupy, honest submarket demand, exit priced off a rent roll that no longer includes you, and then let the occupancy benefit improve a purchase that already stands on its own. Buying a bad building because your company needed a home is renting from yourself at above-market terms, with extra steps.
The partial owner-user structure, occupying some of the building and leasing the rest, deserves its own honesty. It is genuinely attractive: the tenants help carry the debt while the business gets its space. It is also two jobs, and the second one, being a landlord with rollover, TI packages, and lease-up risk on the floors you do not use, arrives whether or not anyone planned for it. Underwrite the leased portion exactly as an investor would, because on those floors, that is what you are.
PropCalc™ handles the owner-user case the way the discipline requires: model the building as the asset it is, with the owner's space as a lease at market terms, so the investment picture and the occupancy picture stay separable and both stay honest. The step into ownership is one of the best moves a business can make in a market like this one. The underwriting is how you make sure it was the building you bought, and not just the idea of it.