PropRate

7–8 Marvin Pl

Cambridge, MA

Market estimate

3.30%–4.10%

Blended 2–4 unit cap rates, Mid-Cambridge submarket. An estimate, not a measured NOI.

An estimate from other people's numbers — the cap-rate equivalent of a Zestimate. Cited, not verified.

Market estimate (ATTOM / CompStak submarket feed)

PropRate

4.73%

$66,200 NOI ÷ $1,400,000 appraised value.

96% of gross income is a signed lease attested on the chain — not an assumed market rent. A number you can underwrite against.

Underwrite it yourself

Slide any assumption — or tap a number to type it exactly. The cap rate recomputes live.

In-place annual rent

Vacancy

Operating expenses

Property tax

Electric, gas & oil (renter-paid)

Water & sewer (owner-paid)

Insurance

Management (6%)

Maintenance & reserves

Net operating income$66,200

Cap rate4.73%

What the market number can't see

Capital improvements verified on the chain — the reason the income holds.

Full two-unit renovation — documented room by room$320,000
The before/after record — kitchens, baths, floors, and finishes across both units — supports the in-place rent and a top-of-band condition rating. Permitted and signed off.
See the verified Build Story

Zillow gives you an AVM. Steve wanted a cap rate you could trust. The market quotes 3.70% from numbers nobody verified. PropRate is 4.73%— built from a signed lease and a permitted, signed-off renovation on the Propreti chain. Same property. One number is an estimate. The other has its receipts attached.

PropRate — named for Steve. Wall Street real-estate banker, then Auldbrass Partners. He said the data would be there one day. It is.

Prototype note: the market estimate is realistic seeded data standing in for a live provider feed (ATTOM / Reonomy / CompStak). The cap-rate math is real and computed live from the inputs above. The verified income and any accepted bid become durable at the persistence backend milestone.