Building stock by era
How old the built environment is, by era, for both counties at once. It answers 'what am I underwriting' and 'what is our replacement exposure' out of the same rows.
A row here is an era, not a building — the count of everything the assessors date to those years. Per-parcel years exist and are the county-wide parcel file, which is not exported yet.
The file
1880–2026
12 rowsCounties in this file: Hennepin, Ramsey · 7 columns available · free, no account, no rate limit.
What the rows look like
10 real rows from this file, spread evenly across it rather than taken off the top — every file here is written in some order, so its first rows are never a fair sample of it. These are the default columns, which is what the download button hands over.
| era | buildings | share |
|---|---|---|
| before 1940 | 110,839 | 22.7 |
| 1940 – 1959 | 119,148 | 24.4 |
| 1960s | 50,141 | 10.3 |
| 1990s | 39,143 | 8.0 |
| 2000 and later | 63,147 | 12.9 |
| before 1940 | 6,423 | 22.6 |
| 1940 – 1959 | 3,322 | 11.7 |
| 1970s – 80s | 6,367 | 22.4 |
| 1990s | 2,148 | 7.6 |
| 2000 and later | 5,503 | 19.4 |
The cuts of this file
Every cut is the same columns, filtered. Pick one and the row count changes; the file does not.
Every column in this file
Columns marked default come down unless you pick your own with
&columns=.
| Column | What it is | In the default file |
|---|---|---|
era |
era | default |
buildings |
buildings | default |
share_pct |
share | default |
stock |
stock | optional |
first_year |
first year | optional |
last_year |
last year | optional |
incomplete |
incomplete era | optional |
Where it comes from
Hennepin and Ramsey assessors, year built
This source does not stamp the day it was published, so we cannot honestly date our copy of it and will not guess. The period the records themselves cover is on the system card.
What this layer cannot answer is stated in full on the system card — read it before quoting a figure.
What you may do with it
Creative Commons Attribution 4.0 International (CC BY 4.0). Share it, change it, build a product on it, sell that product — all fine. The one condition is credit: say it came from Brick & Mortar and link back.
Records published by county assessors. Government data held by a Minnesota state agency or political subdivision, presumed public under the Minnesota Government Data Practices Act (Minn. Stat. ch. 13) and published by the agency itself.
Read the full licence · how we license every dataset, and the two we do not
Without the page
/api/export?dataset=building-stock&format=csv returns the
same file. Call /api/export
with no arguments for the whole catalogue.
Point an AI at it
Every file carries its own source, its capture date and the layer's own warnings in the header, so a model reading one gets the caveats with the numbers rather than the numbers alone. Paste this at an assistant that can fetch a URL:
Read https://brickandmortar.dev/api/export?dataset=building-stock&format=csv
Everything above the header row is provenance and limits. Read it first,
then answer using only what the rows support.llms.txt describes the whole warehouse the same way — what each dataset holds, which counties it really covers, and what it cannot answer.