County or equivalent · 34021
Mercer County, New Jersey
Annual housing permits and reporting coverage
- Published estimate · 2025
- 1,164
- Reported only · 2025
- 1,070
- Added by estimation · 2025
- 94
Reported and estimated units by year
| Year and source | Published estimate | Reported only | Added by estimation |
|---|---|---|---|
| 2023 Census file | 969 | 801 | 168 |
| 2024 Census file | 2,026 | 1,883 | 143 |
| 2025 Census file | 1,164 | 1,070 | 94 |
2024 to 2025 · published estimate -862 units · reported only -813 · added by estimation -49. This split describes the difference between the published columns.
What types of housing were authorized?
| Units in building | Published estimate | Reported only | Added by estimation |
|---|---|---|---|
| One unit | 805 | 732 | 73 |
| Two units | 8 | 8 | 0 |
| Three or four units | 11 | 11 | 0 |
| Five or more units | 340 | 319 | 21 |
Local housing and rent context
| Measure | Estimate and margin |
|---|---|
| Housing units · Census table B25001 | 151,138 ± 116 |
| Median gross monthly rent · Census table B25064 | $1,623 ± $34 |
| Gross rent at least 30% of income · Census table B25070 | 50.1% ± 1.9 percentage points |
| Gross rent at least 50% of income | 25.7% ± 1.8 percentage points |
| Estimated households with a computed rent-to-income ratio | 51,793 |
The 2025 permit estimate amounts to 7.7 authorized units per 1,000 housing units in the ACS estimate. The numerator and denominator cover different periods.
The Vintage 2025 Census housing stock estimate changed from 152,258 in 2024 to 152,739 in 2025 (+481 units). This is a separate model-based inventory estimate.
Permit offices listed under this county code
Use the office pages for their own histories and source coverage notes.
- East Windsor townshipPermit office 34127000 · Mercer County · 5 authorized units
- Ewing townshipPermit office 34148000 · Mercer County · 83 authorized units
- Hamilton townshipPermit office 34201000 · Mercer County · 33 authorized units
- Hightstown boroughPermit office 34223000 · Mercer County · 0 authorized units
- Hopewell boroughPermit office 34233000 · Mercer County · 2 authorized units
- Hopewell townshipPermit office 34235000 · Mercer County · 382 authorized units
- Lawrence townshipPermit office 34263000 · Mercer County · 161 authorized units
- Pennington boroughPermit office 34401000 · Mercer County · 1 authorized units
- PrincetonPermit office 34424000 · Mercer County · 0 authorized units
- Robbinsville townshipPermit office 34546000 · Mercer County · 29 authorized units
- TrentonPermit office 34516000 · Mercer County · 4 authorized units
- West Windsor townshipPermit office 34564000 · Mercer County · 464 authorized units
Sources and definitions
How to read these figures
- The Census Building Permits Survey counts new privately owned housing units authorized by permits. One permit can cover multiple units. The counts describe authorizations, a stage before starts and completions.
- The published estimate includes reported units and Census estimates that fill gaps. The difference is calculated from those two columns. Reported-only units can include records from approved alternative sources. A missing report can leave an office without a usable count.
- County and state totals come from their own Census files. Permit offices can cover places across county lines or areas served by another jurisdiction. The office’s county field is used for navigation.
- ACS housing inventory and rents are survey estimates for 2020–2024. Gross rent includes rent and separately paid utilities or fuels. Rent burden is the share paying at least 30% of income among cash-rent households with a computed ratio. Margins are at 90% confidence. The margin for rent burden is approximate.
- Vintage 2025 county housing stock is a separate Census series. Its model uses building-permit data alongside other inputs. Read stock change and permits as separate measures.
Public sources retrieved November 10, 2026. Building Permits Survey annual data · Survey methodology · American Community Survey data · Download the comparison