Put every building on the same ruler

What dividing by the square foot buys you

No two buildings match in size, so no two prices compare directly — until both are divided by their square footage. Price per square foot is commercial real estate's common ruler: it is how a 6,000-foot retail strip gets weighed against an 11,000-foot one, how an offer gets sanity-checked against the last three sales on the corridor, and how replacement cost enters the argument — when buildings trade meaningfully below what they cost to build per foot, construction stops and existing stock gets interesting. Rent per square foot is the same ruler laid against income, and it is how nearly every commercial lease is quoted.

How the numbers are computed

Price ÷ square feet, and rent ÷ square feet — the rent stated both annually, the convention in office, retail and industrial quotes, and monthly, the convention in some coastal markets and most small-space listings. The two rent forms differ by exactly a factor of twelve, and misreading one for the other is a real and expensive mistake: a space quoted at $2.75 monthly is a $33 annual space, not a bargain at a tenth of the market. The division is trivial; the discipline is the denominator — compare rentable feet to rentable feet, gross building area to gross building area, and never one to the other.

Using it without being misled by it

Per-foot figures normalize size and nothing else. Within one submarket and one property type they are an excellent screen — an industrial building at double the going rate needs a story, and a listing far under it usually has one you will not like. Across types and markets they mislead, because the metric says nothing about income: a $180-a-foot building renting at $14 out-earns a $120 building renting at $7, and only the income metrics can say so. The practical pairing is rent per foot against price per foot — their ratio is a rough gross yield — and then the cap rate on actual NOI to make the decision properly.

Common mistakes

Mixing measurement bases is the big one: rentable square feet carry a 10–20% load factor over usable, so a rent computed on usable feet will always read expensive against listings computed on rentable. Annual-versus-monthly confusion is the second, and it survives because both conventions are legitimate somewhere. Comparing a NNN rent per foot to a gross one ignores the nets — put both on an effective basis first (the NNN lease calculator does exactly that). And on mixed-use or partly-finished buildings, decide what the square footage even is before dividing: a heated warehouse with 2,000 feet of office inside is two different per-foot markets sharing one roof.

Per-foot numbers travel one building at a time; a lender reads the whole book at once. The free Schedule of Real Estate Owned generator lays out every property — square footage, value, income and debt — in the format underwriters ask for.