Office in 2026 is the most interesting risk-reward in commercial real estate and the least forgiving place to underwrite carelessly. Buildings trade at wide caps and prices below replacement cost, debt is available but tight, and the buyers stepping in are value investors, owner-users, and operators with a reposition thesis. Every one of those deals lives or dies on the same question: is the rollover being priced honestly?
Because office rollover is not like other rollover. When an office suite turns, the downtime runs long, the tenant improvement package on the replacement lease is heavy, the free rent it takes to sign in a tenant's market is real, and the leasing commission sits on top. Stack those and a single suite turning can consume years of that suite's rent before the new tenant pays a full month. A model that treats office vacancy as a percentage assumption has not underwritten the deal. It has decorated the price.
This is why weighted average lease term does the screening work in office. Short WALT is not an abstraction; it is a schedule of TI packages, downtime, and free rent arriving on specific dates, and the model should convert it into exactly that. It is also why the spread between face rent and effective rent matters more in office than anywhere else: a rent roll can look healthy at face and be signing every renewal into concessions that hollow out the cash flow underneath it.
So the software bar for office is specific. Suite-by-suite rollover costs, set per tenant, not per building: this tenant's renewal odds, this suite's likely downtime, this floor's TI reality. Effective rent visible next to face rent. The building's physical economics in the model where they belong, parking ratio and load factor included, because suburban office leases are won and lost on the parking ratio before anyone reads the rent. And the exit priced against a defensible basis story, since below-replacement-cost is the thesis on most office buys and the model should let you interrogate it rather than assume it.
Generic underwriting products flatten precisely these things, because they were built for asset classes where flattening is survivable. Office is where it is not: the concessions, the downtime, and the TI are the deal, and averaging them away removes the exact information the buyer is being paid to have an opinion about.
PropCalc™ models office at the suite level, with per-tenant rollover costs, rent-weighted WALT computed live as the rent roll changes, and the office property profile carried alongside the financials. There is a live office deal on this site, fictional numbers, fully inspectable, linked below. The fastest way to evaluate any claim on this page is to open it and change an assumption.