Aerial view of the Old Port, Portland, Maine at dusk

Greater Portland, Maine

Commercialrealestate,underwrittenintheopen.

A deep parcel index and an institutional underwriting engine. Explore the market like a data story, test what your building is worth, then talk to an agent.

Explore property map→Test our brain

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How we know

We know every parcel.

Greater Portland, indexed lot by lot and kept current — ownership, footprint, use, and history on every property in the market.

12,000+parcels indexed

Down to the code

Every zoning line.

Use, overlay, setback, height and lot coverage — mapped to each lot, so what can be built (or changed) is never a guess.

Lot-levelzoning & overlays

And the timing

Every owner. Every mortgage.

Maturities, origination dates and the rate they locked — the signals that quietly say a building is likely to trade before it ever hits the market.

Likely to sellsignals, surfaced early

So you move first.

The whole market, read like an instrument. Explore it on the live map, or put our underwriting brain to the test.

Explore property map→Test our brain

Explore the market

A live map of the Old Port

Select any parcel and watch the camera fly in — market rent, vacancy, building age, and last sale animate out as a data story.

Open the map →

Test our brain

What's your building worth?

Enter a few facts and our underwriting engine returns an estimated value, autofilled lease rate, and market vacancy in seconds.

Run a valuation →

Talk to an agent

Buying, selling, or just curious?

Tell us about the property or the deal you have in mind. A GreenMars agent will follow up — no obligation, and your details stay private.

A real underwrite, not a Zestimate.
Local comps and market rates, refreshed daily.
Direct line to a broker who knows the submarket.