Key takeaways
- There is no list price. The cost depends on which TR1 categories your permit requires, how many site visits they generate, and how much laboratory testing the concrete, soil and masonry need.
- Agencies quote in three ways: per visit, per test, or a lump sum for the project. Each has a place; the mistake is comparing one against another without converting them to the same basis.
- The cheapest proposal is often the one that assumes the fewest visits. If the schedule slips or pours get split, the "extras" decide the final bill.
- A good proposal lists the categories, the assumed number of visits and tests, the hourly or per-visit rate for anything beyond, and the laboratory's license and accreditation.
In this article
Every general contractor in New York asks the question and few agencies answer it in writing. The honest answer is that the cost of special inspections is a function of your permit and your schedule, not a menu item. This article explains what moves the number, how proposals are structured, and how to read two of them side by side so the one you pick is the one you actually pay.
What you are paying for
A special inspection agency sells two things: people on your site and tests in its laboratory.
- Site visits. A certified inspector comes to witness work that the TR1 lists for your permit: rebar before a pour, welds as they are made, fill as it is compacted, masonry as it is grouted. Each visit has a duration (a slab pour may take a full day; a footing inspection an hour) and a travel component.
- Laboratory testing. Concrete cylinders, masonry prisms, soil density and Proctor tests, grout and mortar samples. Each sample is a line item with a test method behind it (ASTM C39 for cylinders, ASTM D1557 for Proctor, and so on).
- Engineering review and paperwork. A licensed Professional Engineer reviews reports, signs the TR1 categories, and handles DOB correspondence. This is usually folded into the rates rather than billed separately.
The number of visits and tests is driven by your project, not by the agency. That is why no two quotes for "concrete inspection" are the same.
The six things that move the price
| Driver | Why it matters |
|---|---|
| TR1 categories | A job with concrete, soils, masonry and steel needs four kinds of inspectors and three kinds of lab work. A one-category job needs one. |
| Number of pours and placements | Each pour is a visit plus a set of cylinders. Ten small pours cost more than two large ones of the same volume. |
| Volume of concrete | The code requires sampling at least once per 150 cubic yards (NYC BC §1905.6), so volume sets the minimum number of cylinder sets. |
| Schedule and continuity | Continuous inspections (pile driving, welding) are billed by the day. A schedule with gaps means more mobilisations. |
| Location and access | Manhattan sites with no parking, night pours, and weekend work carry premiums at most agencies. |
| Reporting requirements | Daily reports to a Procore portal, lender reports, or special formats take office time; some agencies price it, some absorb it. |
How agencies quote
Per visit. A rate for each inspection visit (often a half-day and full-day rate), plus a per-sample rate for lab tests. Simple and transparent; the risk is on you if the number of visits grows.
Per test or unit. Common for laboratory-heavy work: price per cylinder set, per Proctor, per core. Usually combined with a per-visit rate for field time.
Lump sum for the project. One number for the scope on the TR1, based on an assumed schedule and quantity. Predictable for budgeting; read the assumptions, because anything outside them is billed as an extra.
Time and materials. Hourly rates for inspectors and engineers, plus tests. Used for open-ended work such as alterations where the scope is unclear.
Most proposals mix these: a lump sum or per-visit basis for the field work, unit prices for the lab, and hourly rates for anything unforeseen.
What a good proposal includes
Before you compare prices, check that each proposal contains the same information. If one is missing an item, the comparison is not fair.
- The TR1 categories covered, by name and code section, and any the agency is not covering.
- The assumed quantities: number of visits (or days), number of cylinder sets, number of soil tests, and the concrete volume the quote is based on.
- Unit rates for extras: additional visits, canceled visits (the "show-up" fee), overtime, night and weekend premiums, additional samples.
- What a visit is: minimum hours, travel included or not, how a visit that runs long is billed.
- Reporting: frequency, format, and whether Procore or other portals are included.
- The laboratory: its DOB license number and accreditation (A2LA or equivalent). Tests from an unlicensed lab do not satisfy the DOB.
- Who signs: the Professional Engineer responsible for the TR1, and the agency's DOB registration (SIA number and class).
Comparing two quotes
Put both on one page and convert them to the same basis.
- If one is lump sum and the other per visit, multiply the per-visit rates by the number of visits the lump-sum proposal assumed. Now they are comparable.
- Add the show-up and cancellation fees to a realistic number of weather days. New York has them.
- Check the lab line separately. Unit prices for cylinders vary, and the number of sets is set by code, not by the agency, so the difference is pure price.
- Ask each agency what happens when a pour is split into two days. The answer tells you how the "extras" will go.
The lowest number on the first page is rarely the lowest number on the last invoice. The agency that states its assumptions is the one you can hold to them.
Where the hidden costs are
- Failed tests. A low cylinder break means additional testing (further breaks, sometimes cores) and engineering review. Ask whether retests are at the unit rate or at a premium.
- Missed inspections. If work is covered without the inspection, the cure (uncovering, coring, an engineer's evaluation) costs far more than the visit would have. This is the single largest "cost" on most troubled jobs and it appears on no proposal.
- Changing agencies mid-project. A new agency cannot certify work it did not witness. Switching to save money usually costs more.
- Closeout. If reports and logs are not kept as the job goes, assembling them for the final TR1 is billable office time, and it delays the Certificate of Occupancy, which has its own cost.
Two questions usually follow the price: who is actually obliged to pay, and which class of agency your job needs.
Frequently asked questions
Can I get a fixed price for the whole project?
Yes, if the schedule and quantities are known. Expect the proposal to state the assumptions and to bill extras beyond them. For projects with an uncertain schedule, per-visit pricing is often fairer to both sides.
Does the owner or the contractor pay?
Under the NYC Building Code the owner is responsible for engaging the special inspection agency, which keeps the agency independent of the contractor. In practice the cost is often carried in the general contractor's budget and passed through. Either way, the agency reports to the owner and the design professional, not to the party being inspected.
Why is the laboratory a separate line?
Because it is a separate license. Concrete, soil and masonry samples must be tested in a DOB-licensed laboratory; agencies without their own lab subcontract the testing and mark it up. An agency with its own lab controls both the price and the turnaround.
Is the cheapest agency a risk?
Not necessarily, but an unusually low price usually means fewer assumed visits, a subcontracted lab, or inexperienced inspectors. Ask the three questions above and the answer becomes clear.
Conclusion
The cost of special inspections is set by your permit and your schedule: how many categories, how many visits, how many tests. The price difference between agencies is in the assumptions and the extras, so compare proposals on the same basis and read the lines about additional visits, cancellations and laboratory work. The agency that writes those lines down is the one that will not surprise you at closeout.
Written by the engineers and laboratory technicians of Metric Consulting and Inspection, a Class 1 special inspection agency with a DOB-licensed concrete testing laboratory in Hicksville, New York, serving NYC construction since 2003.