Data · housing age
How Many Homes Were Built Before 1940 in Each Zip Code?
Census estimates for the 11 zip codes we serve, with margins of error. In six of them, more than four in ten homes were built in 1939 or earlier.
- ACS 2020–2024 5-year
- Margins of error shown
- CSV download
What share of homes here were built before 1940?
Across our 11 zip codes, about 43% of housing units were built in 1939 or earlier, according to American Community Survey 2020 to 2024 estimates. The share ranges from 17.8% in Wyncote 19095 to 56.8% in Mt. Airy 19119, with Merion Station 19066 and Germantown 19144 both above half.
Housing units built 1939 or earlier, by zip code
| Zip (ZCTA) | Area | Housing units | Built 1939 or earlier | Share | Share MOE (±) |
|---|---|---|---|---|---|
| 19118 | Chestnut Hill (incl. part of Wyndmoor) | 5,025 ±356 | 2,349 ±249 | 46.7% | 3.7 pts |
| 19119 | Mt. Airy | 13,650 ±558 | 7,754 ±640 | 56.8% | 4.1 pts |
| 19144 | Germantown | 24,162 ±917 | 12,573 ±908 | 52.0% | 3.2 pts |
| 19138 | East Germantown | 13,552 ±1,162 | 5,815 ±975 | 42.9% | 6.2 pts |
| 19027 | Elkins Park (incl. part of Abington) | 8,575 ±506 | 2,507 ±352 | 29.2% | 3.7 pts |
| 19095 | Wyncote | 3,834 ±378 | 683 ±181 | 17.8% | 4.4 pts |
| 19038 | Glenside (Cheltenham and Abington parts) | 11,950 ±496 | 3,844 ±330 | 32.2% | 2.4 pts |
| 19012 | Cheltenham village | 2,320 ±226 | 794 ±175 | 34.2% | 6.8 pts |
| 19046 | Jenkintown (incl. parts of Cheltenham and Abington) | 8,525 ±451 | 2,782 ±330 | 32.6% | 3.5 pts |
| 19066 | Merion Station | 1,831 ±187 | 967 ±126 | 52.8% | 4.3 pts |
| 19072 | Narberth (incl. Penn Valley) | 4,406 ±282 | 1,992 ±237 | 45.2% | 4.5 pts |
Source: U.S. Census Bureau, ACS 2020–2024 5-year estimates, table B25034 (Year Structure Built), ZIP Code Tabulation Areas. Margins of error are at the 90% confidence level; the share's margin is derived with the Census Bureau's ratio formula. Download: pre-1940-homes-by-zip.csv.
Why does the age of a house matter for a new roof?
It matters because prewar roofs sit on board decking, often over earlier roof layers, with chimneys flashed into old mortar and gutters sometimes built into the roof edge. Those conditions add deck, flashing and gutter work that a newer house rarely needs, so estimates on older houses vary more.
See roof replacement on older houses for what we check, and the glossary for the terms.
Notes on the data
- Zip Code Tabulation Areas approximate postal zip codes and cross municipal lines: 19118 includes part of Wyndmoor across the city line, 19027, 19038 and 19046 include parts of Abington Township, and 19072 includes Penn Valley in Lower Merion.
- “Built 1939 or earlier” is the census's oldest category. Owners often don't know a house's exact year, so the answers carry error beyond the stated margin.
- The 43% total is the sum of the 11 rows (42,060 of 97,830 units) and has no published margin of error.
Data questions
Where can I check these numbers myself?
Sources and checked date
- U.S. Census Bureau, ACS 5-year 2020–2024 summary file, table B25034
- U.S. Census Bureau, data.census.gov table B25034
Last checked 2026-10-29.
Own one of these older houses?
Tell us where the house is, how old the roof is and what it is doing. If you have photos, say so and we will ask for them by email. Outside our core area? Send the form and ask.
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