Block and PaperMake a map
Maine, United States

Every building in Portland, Maineby the year it was built

The map opens on today’s skyline. Play or scrub to explore recorded dates; undated buildings stay visible as optional present-day context. Documented former buildings appear in rust and disappear in their demolition year. Historical coverage is partial; missing buildings and dates remain unknown.

2026

11dated surviving buildings built by this year

Decade built
←1910
1910
1920
1930
1940
1950
1960
1970
1980
1990
2000
2010
2020
no year
11 of 26,814 footprints dated

26,803 undated footprints are context only, not evidence they existed in the selected year.

No dated former buildings found in this import. Historical coverage is incomplete.

drag to pan · ⌘ or Ctrl and scroll to zoom · hold ⌃ and drag to tilt
heights ×3 at this zoom

Overture Maps buildings outlines · OpenStreetMap building construction dates years
heights exaggerated when zoomed out

WHAT THE MAP HOLDS

Portland in 26,814 buildings.

26,814Buildings standing today

Every structure in the Overture footprint data inside the mapped area of Portland, garages and sheds included.

11Carry a year built (<1%)

Dates come from building inventories, assessor parcels or explicit mapped construction dates. Parcel dates can describe the main building rather than every outbuilding. 26,803 buildings have no year at all and remain grey as optional present-day context.

61 mTallest structure

The Casco. Heights come from lidar or the source data where we have it. Otherwise we estimate from floor counts.

1807Oldest dated building

Portland Observatory. We take this only from buildings with their own record, never from an area estimate.

Recorded construction yearsHow the years were sourced

Dates come from building inventories, assessor parcels and explicit mapped construction dates. A parcel date can describe the main building rather than every outbuilding.

THE SHAPE OF THE STOCK

Which decades are left.

Each bar counts surviving buildings with a recorded date in that decade. A short bar can reflect fewer surviving buildings or missing construction dates. It does not measure everything built or demolished during that decade.

Portland buildings standing today, by the decade they were builtThe tallest bar is no year with 26,803 buildings. 1800s 1, 1850s 2, 1870s 1, 1900s 1, 1930s 2, 1960s 2, 1970s 1, 1990s 1, no year 26,803.05.0k10k15k20k25k180019001960no yearDecade the building went up
Buildings standing today. Portland, 26,814 mapped buildings, 11 with recorded construction years.
HOW TO READ THIS MAP

Colour, height, and what to trust.

Drag to pan. Hold ⌃ or use the right mouse button to tilt. Scrub the timeline to stop on any year. Everything you change goes into the address bar, so copy the URL or press Share and the other person sees exactly what you see.

  • Decade built. Warm colours mark the oldest buildings left and cool colours the newest, one step per decade from 1910 on.
  • Grey. No construction year on record. Undated buildings stay visible as present-day context throughout the timeline. Hide them with “Show undated present-day buildings” to view dated records alone.
  • Height mode. Switch the colour from age to height and the same boxes become a relief map of where Portland is tall.
  • Heights are exaggerated when you zoom out. At the widest view they stand up to forty times taller, so a whole city still reads as a skyline. From zoom 15 in, the boxes are at true scale.
DATA AND METHOD

Where these buildings come from.

  • Coverage target: 1800–2026. 11 of 26,814 current footprints have a recorded construction year (<1%). 26,803 remain undated. These counts cover the map’s extraction area, which can extend beyond city boundaries.
  • Historical records are incomplete across 1800–present. Missing buildings, unknown demolition dates and undocumented replacements remain gaps; an empty location in an earlier year does not establish that the site was vacant.
  • 0 documented former buildings with usable lifetimes in this dataset. No usable historical lifetimes were found in this import. Standing-building counts and charts exclude these historical records.
  • Repeated census-tract median dates, including 1938, are no longer assigned as construction years. Undated buildings remain unknown; recorded 1938 dates are retained.
  • The main footprints describe surviving buildings. The rust historical layer adds documented former buildings only between their construction and demolition years. Dots mark locations where a historical outline is unavailable. This is a partial reconstruction, not a complete inventory of past buildings.
  • Heights are measured where the source has them and estimated from floor counts otherwise. 22,110 of 26,814 are measured.
  • Below zoom 12.5 the map draws 100 m cells instead of individual footprints, so you can see a whole city at once. Cells use the median recorded year of their current buildings; zoom in for individual outlines and construction years.
  • Built 2026-09-09. This is a snapshot, not a live feed.
TAKE IT OFF THE SCREEN

Put Portland on paper.

A browser tab is a fine place to lose an hour, but it is not a wall. The studio prints a street map of the same place in colours you pick, with your own words underneath.

Make a Portland print See the Portland print page ↗
KEEP LOOKING

Nearby skylines.

All 100 skyline maps ↗

Boston

Massachusetts, United States
Buildings
From
123,190
1800
Recorded construction years

Providence

Rhode Island, United States
Buildings
From
79,352
1808
Recorded construction years

Burlington

Vermont, United States
Buildings
From
20,088
1830
Recorded construction years

Montréal

Quebec, Canada
Buildings
From
144,980
1800
Recorded construction years