Does the project still clear the 2026-06-30 179D gate, and what is it worth on the 2026 rate table?
| Gate result | — | |
|---|---|---|
| Days inside the 2026-06-30 gate | — | days |
| 2026 deduction rate | — | per sq ft |
| 179D deduction dollars still claimable | — | dollars |
| 45L credit on homes acquired in time | — | dollars |
| Total still on the table | — | dollars |
| Which return it goes on | — |
This page is the working piece. The full pack has everything below.
Does the project still clear the 2026-06-30 179D gate, and what is it worth on the 2026 rate table?
A third-party 179D engineering study with the site visit and energy model is commonly quoted at 5000 to 15000 dollars per building.
Buy the full version — $60It answers one question the 2026 sunset made confusing: is this project still worth a 179D deduction? You give it 7 inputs - construction start, conditioned floor area, modeled savings, prevailing wage status, placed-in-service year, homes acquired, and their 45L tier - and it returns 7 outputs, including the gate result, the 2026 rate per sq ft, and the deduction dollars still claimable.
US architects, engineers and design-build contractors who take 179D allocations from government and tax-exempt building owners, and home builders still holding 45L homes. If you are deciding whether a 2026 project is worth the cost of an energy model and an allocation letter, this is the check that comes first.
Because the sunset reads like an end date and the models were trained on the old rules. Ask one about 179D in late 2026 and it will tell you the deduction is gone. It is not gone for projects that began construction on or before 2026-06-30, and the free calculators that survive still price on the 2025 table of 5.81 per sq ft rather than the 2026 cap of 5.94.
The whole calculation is free, for every project, with no key and no cap: the gate test, the 2026 rate, the 179D dollars, the 45L credit and the return it goes on. The 60 dollar key adds a different axis - a dated CSV of every project you have checked, so you can hand it to a CPA, and alarms before a placed-in-service or amended-return window closes.
A third-party 179D engineering study with the site visit and energy model is commonly quoted at 5000 to 15000 dollars per building. That is the right spend once you know a project clears the gate. It is a painful spend on a project that started 2026-07-02 and never qualified at all, which is exactly what this check tells you first.
One question, answered by the person who built it. Your email only if you want the answer sent.