Loss Factor: NYC Office Leasing, Explained

How the number works in a New York lease

The lease quotes a rentable square footage, and that figure drives the rent, the escalations, and usually the electric and cleaning charges too. Rentable area starts with the floor you occupy and adds a share of the building's common space, and no city agency audits the math; most owners measure under an industry convention, so the loss factor is, in practice, whatever ownership says it is, within what the market will tolerate.

We therefore treat the loss factor as a pricing input rather than a fact of geometry. What matters on a tour is how much of the floor will take desks, conference rooms, and a pantry once the core and corridors are subtracted, and on that test side-core buildings usually measure better than center-core towers.

A worked example on the numbers

Take a 10,000 square foot lease at the citywide median asking rent on our book, $75 per square foot per year, which is $750,000 a year however the floor measures. At a 15% loss factor you occupy about 8,500 usable feet and pay roughly $85 for each foot you can actually use; at 25% you are down to about 7,500 feet and roughly $96. Same lease, same rent check, and a spread of more than ten dollars per usable foot.

We run that division on every shortlist, because a space asking below the median on an inefficient floor can cost more per usable foot than one asking above it on an efficient floor.

What is negotiable, and what we push on

The percentage itself rarely moves, and arguing an owner down from a stated loss factor is usually wasted effort. What moves is everything the percentage touches. We get the loss factor and the measurement method in writing before terms are traded, run a test fit so the client knows the real desk count, and negotiate the rent against the usable area the fit proves out, an ordinary pricing argument instead of an unwinnable measurement one.

On longer terms, expansion space, must-take floors, and renewal options should carry the same measurement basis as the original premises, and any owner's right to remeasure should never raise the rent on space you already occupy. These protections exist only if written in, so confirm the exact language on the specific lease.

The traps that cost tenants money

• Comparing asking rents across buildings as if the quoted footage were one consistent measurement, when a 15% floor and a 25% floor at the same rent are materially different deals.
• Planning headcount from the marketing plan, which is drawn on rentable area; only a test fit tells you whether the last two offices actually fit.
• Forgetting that escalations, electric, and cleaning are typically billed on rentable feet too, so an inefficient floor inflates every line of occupancy cost.
• Accepting an unrestricted right to remeasure, which can raise the rent mid-term or at renewal on the same physical space.

None of these are exotic, and every one is visible before signing if someone on your side of the table is looking.