What New Jersey's Empty Square Footage Box Tells You

Only 5.5% of New Jersey's 640,741 building permits record a square footage. Those 35,479 permits carry a median project cost of $137,250, against $4,980 for the 605,260 that leave the box at zero. In New Jersey, whether that field is filled at all predicts job size better than the number inside it.

TL;DR

• Only 35,479 of 640,741 New Jersey permits record a square footage, and that is not a defect.
• Filled box: $137,250 median project cost. Empty box: $4,980. A 27-fold spread.
• New Jersey's fee formula decides which permits get measured, not the municipality.
• The signal stacks with subcode count rather than duplicating it.

Which New Jersey permits carry a square footage?

Almost entirely the ones that add floor area.

Split our New Jersey file by the work class recorded on the permit and the pattern is close to binary. Permits for new work state a square footage 81.9% of the time. Additions state one 87.7% of the time. Alterations state one on 631 records out of 585,082, which is 0.1%. Demolition permits state one five times in 14,150.

Work class	Permits	With square footage	Share	Median cost with	Median cost without
Alteration	585,082	631	0.1%	$65,000	$5,000
New	26,998	22,124	81.9%	$173,000	$5,500
Addition	14,511	12,719	87.7%	$95,000	$8,000
Demolition	14,150	5	0.0%	n/a	$2,000

Read the last two columns across, because that is where the useful part sits. Within every class, the permits that record a floor area cost several times more than the ones that do not. Even inside alteration, the least differentiated category in the file, the 631 measured permits run 13 times the median of the other 584,451.

Why does New Jersey's fee formula decide what gets measured?

Because floor area is an input to one fee calculation and irrelevant to the other.

New Jersey construction permits are issued by municipal construction officials under a statewide code, the New Jersey Uniform Construction Code at N.J.A.C. 5:23. The fee standards live at N.J.A.C. 5:23-4.18. For new construction, the fee is computed on the volume of the building, at a rate per cubic foot, with volume determined under N.J.A.C. 5:23-2.28. For renovations, alterations and repairs, the fee is computed on the estimated cost of work, at a rate per $1,000.

So a new building has to be measured before anyone can price the permit. A kitchen renovation does not. The applicant states a cost of work and the fee follows from that.

This matters more than it first appears. The empty square footage box is not a municipality being careless or a data vendor dropping a column. It is a field the process never required, which means its absence is consistent, predictable and statewide rather than random. Consistent absence is something you can filter on. Random absence is not.

Does the empty box actually predict job size?

It does, and it survives the obvious objection.

The obvious objection is that square footage presence is just a proxy for something we already knew. New Jersey builds a permit from one application plus a technical section per discipline, and the number of subcodes named on a permit is already a strong size predictor, as the four-subcode cohort shows. If the measured permits were simply the four-subcode permits, this would be the same finding wearing a different hat.

They are not. Hold the subcode count fixed and the gap persists inside every bucket.

Subcodes named	Permits	With square footage	Median cost with	Median cost without
1	341,007	6,494 (1.9%)	$15,657	$3,950
2	110,169	3,751 (3.4%)	$27,000	$8,500
3	55,400	2,987 (5.4%)	$66,938	$19,500
4	41,560	21,237 (51.1%)	$214,000	$46,500
No subcode tag	92,605	1,010 (1.1%)	$31,612	$2,300

Three things fall out of that table. Measured permits run three to four times the unmeasured ones at every subcode count, so the fields are reading different properties of the job. The four-subcode group splits almost in half, and its blended $124,000 median hides a $214,000 top and a $46,500 bottom. And the 92,605 records carrying no subcode tag at all, the ones easiest to discard, contain 1,010 permits with a $31,612 median, which is more than six times the statewide figure.

A single-subcode permit that records a floor area is worth more attention than a three-subcode permit that does not.

What is the real cost per square foot in each county?

Statewide, the median is $97.37, and the county spread is wider than most people expect.

Across the 29,362 New Jersey permits recording at least 100 square feet and a positive project cost, the median declared cost is $97.37 per square foot, with a quartile range of $53.75 to $184.08.

County	Permits with sq ft	Share	Median $/sq ft
Union	1,337	4.7%	$154.55
Bergen	3,091	4.6%	$133.86
Hudson	189	1.7%	$124.92
Mercer	2,151	5.6%	$114.41
Essex	1,841	5.3%	$114.18
Cape May	1,892	11.9%	$109.52
Morris	2,623	5.5%	$107.15
Monmouth	3,963	5.9%	$103.33
Somerset	988	2.9%	$101.75
Middlesex	2,111	3.4%	$97.95
Passaic	666	4.0%	$95.16
Ocean	6,260	10.4%	$94.95
Sussex	683	4.1%	$76.36
Warren	607	6.4%	$72.44
Burlington	1,255	3.5%	$71.89
Atlantic	1,209	8.2%	$69.15
Hunterdon	734	5.2%	$67.64
Camden	1,348	4.2%	$66.80
Gloucester	1,757	7.0%	$61.34
Cumberland	415	7.1%	$48.27
Salem	359	9.6%	$33.33

Union at $154.55 against Salem at $33.33 is a spread of more than four times, and it tracks the north-south economic gradient rather than anything about construction practice. Ocean County is worth a second look for a different reason: it produces the most measured permits in the state at 6,260, but its median measured job is only 360 square feet, which points at a large volume of small structures rather than houses.

One caution matters more than the table. Project cost on a permit is the cost of work declared to the construction official. It is not the contract price a homeowner pays, and it generally sits well below it. These figures are sound for comparing counties, jobs and years against each other, and unsound as a quote.

What can this data not tell you?

The limits here are specific and worth stating plainly.

Our New Jersey file carries no contractor name and no owner name on any of the 640,741 records, and no applicant name either. There is no latitude or longitude anywhere in New Jersey, so radius and drive-time targeting are not available. Street address is present on 88.4% of records, and the coverage is uneven, running above 95% in Union, Hudson and Essex and below 75% in Warren, Salem and Atlantic.

On valuation, 14,540 records carry a project cost of zero, 4,741 carry exactly one dollar and 3,958 fall between two and ninety-nine dollars. Those 23,239 records are 3.6% of the file. Every figure in this article is a median for that reason.

And square footage itself is a floor-area statement made for fee purposes, not a survey. A 1,368 square foot median across the measured permits describes what applicants wrote down. Treat it as a size band rather than a measurement.

New Jersey data also runs behind our other states on freshness, so it suits territory planning and quarterly sizing better than same-week outreach. The 20 business day statutory clock is the better tool when timing is what you care about.

How should you build the filter?

Four passes, in this order.

Start by splitting on square footage presence rather than value. That one binary sorts the file into a $137,250 median group and a $4,980 one before you have looked at anything else.

Then bring in the subcode count and use the two together. The grid above gives you eight cells to choose from, and the top cell holds 21,237 permits with a $214,000 median. If you want the reasoning behind subcode counting on its own, the 21-county foundation piece sets it out.

Third, decide whether you want the common cohort or the rare one. Filtering for new work with a floor area gives you 22,124 predictable, sizeable jobs. Filtering for alteration with a floor area gives you 631, and those 631 are renovation work substantial enough that somebody had to measure it. Different businesses want different halves of that.

Fourth, benchmark against the county rather than the state, and score what you keep. Whether the cohort you have chosen actually pays is a separate question with its own method, set out in measuring return on permit-triggered outreach.

How permits.llc fits in

We hold 640,741 New Jersey permit records covering all 21 counties and 496 municipalities, the largest single-state file we carry. Every number in this article came out of it, including both tables and the county benchmarks, and the fee rules behind them come from N.J.A.C. 5:23.

A permit is a signal about the property owner, not the contractor, and in New Jersey that signal arrives with no name attached. What arrives instead is the shape of the job: which subcodes were filed, what it was declared to cost, and now whether anyone had to measure it. That last field has been sitting in the file the whole time, reading as empty on 94.5% of records, which is exactly why it is still worth something.

Pull the file and run the square footage split against your own counties at the free NJ permit download. To compare measured-permit density across the 21 counties before you commit a territory, browse New Jersey coverage by county.