Last checked: October 2026. Building permits do not last forever. Under the model rule most U.S. cities start from, a permit becomes invalid if work does not start within 180 days of issuance, or if work is suspended or abandoned for 180 days after it starts (IRC R105.5). This free calculator estimates when your permit expires and when to ask for an extension.
Many cities count a passed inspection as proof that work is active, so each passed inspection often restarts the clock. Some cities use 365 days or other periods, so set the period your city uses if you know it. Your building department's record is the official answer. See our disclaimer.
Leave blank if no inspection has passed yet.
How the calculation works
- No inspection yet: the permit expires one period after the issue date.
- At least one passed inspection: the calculator assumes each passed inspection shows the work is active, so the permit expires one period after the last passed inspection.
- Extension: the model code lets the building official grant extensions of up to 180 days each when you ask in writing and show a good reason. Ask before the permit expires.
Rules vary. Some departments count only certain inspections, some count from the application date, and some require a fee to extend or reactivate. Check your permit's status online with our Building Permit Lookup by State.
What if my permit already expired?
Call the building department before doing more work. Many cities can reactivate or renew a recently expired permit, sometimes for a fee, but work done after expiration may need to meet newer codes or a new permit. Our guide to expired or open building permits walks through your options, and our contractor-abandoned-job guide covers permits left open by a contractor.
FAQ
Does a failed inspection reset the clock?
Usually not. Most departments look for a passed inspection or other approved progress. That is why this calculator asks for the last passed inspection.
Can I request more than one extension?
Often yes, but each one is at the building official's discretion. A written request with a short schedule for finishing the work helps.
Does an open or expired permit matter when I sell?
Yes. Open and expired permits show up in permit searches and can delay a sale. See selling a house with unpermitted work.
Can I link to this calculator?
Yes. Contractors, inspectors and real estate professionals are welcome to share it with clients.
Where the 180-day rule comes from
The default in this calculator comes from Section R105.5 of the 2021 International Residential Code. In that edition, a permit becomes invalid if the work is not started within 180 days after the permit is issued, or if, after work starts, more than 180 days pass between inspections. The building official may grant one or more extensions of up to 180 days each, and the extension has to be requested in writing with a good reason (ICC, 2021 IRC Chapter 1). Tying the clock to inspections is why the calculator asks for your last passed inspection.
The same chapter has a separate clock for applications that have not been issued yet: an application is considered abandoned 180 days after filing unless it is being pursued in good faith or a permit has been issued, and extensions are again up to 180 days each on written request (IRC R105.3.2). If your plans are still in review, that is the clock to watch, not this one.
Real local rules: how much they differ
Cities adopt the model code and then amend it. Here are a few published examples, so you can see why the "Other" option exists. Always read your own city's rule.
| Jurisdiction | When a permit expires | Extensions or renewals |
|---|---|---|
| 2021 IRC model code | Work not started within 180 days of issuance, or more than 180 days between inspections | One or more written extensions, up to 180 days each, with justifiable cause (ICC) |
| Frankfort, Illinois | Work not started within 180 days, or suspended or abandoned for 180 days | Written extensions of up to 180 days each, but a permit is valid for no more than 365 days even with an extension (Frankfort Code § 150.20(E)) |
| Los Angeles, California | Permits are valid for two years, but expire after 12 months if work has not started, or if work is suspended or abandoned for a continuous 12 months | Extensions may be granted for unusual construction difficulties (LAMC 98.0602); extension requests must be made no later than 90 days after expiration (LAMC 98.0605) |
| Seattle, Washington | Construction, demolition, mechanical, and grading permits typically expire 18 months after issuance | Renewal only during the 30 days before expiration; an approved renewal adds 18 months. A permit expired for less than one year can be reestablished (Seattle SDCI) |
For Los Angeles you would set the calculator to 365 days for the start and inactivity limits, keeping in mind that the two-year overall limit still applies. For Seattle the clock does not reset with inspections, so use "Other", enter the number of days from your issue date to the expiration date printed on your permit, and leave the inspection date blank.
How to ask for an extension
- Find the official expiration date. It is usually printed on the permit card or shown in the city's permit portal. If the portal date and this calculator disagree, the portal wins.
- Check whether an inspection would solve it. Under the 2021 model code, the inactivity clock is measured between inspections. If you are close to a rough-in or framing inspection, scheduling it may be simpler than asking for more time. Our inspection prep guide covers what inspectors look for at each stage.
- Write before the deadline. The model code requires a written request and a justifiable reason. Some cities, such as Seattle, only accept renewals inside a set window before expiration, so do not wait until the last day.
- Include the basics: permit number, property address, what work is complete, why work stalled (for example a backordered material, a contractor change, or weather), and a realistic plan with dates for the remaining work and the next inspection.
- Ask about cost and keep the reply. Some departments charge for extensions or renewals; Seattle, for example, lists a renewal fee. Save the written approval with your permit records, since buyers and lenders may ask for it later.
If your contractor pulled the permit, the request usually has to come from the permit holder. Our guide on who pulls the permit explains why that matters.
Worked example
Say your permit was issued on March 2, 2026, and your city follows the 180-day model rule.
- With no inspection, the estimated expiration would be August 29, 2026 (180 days after March 2).
- Your rough-in inspection passed on May 15, 2026. Counting 180 days from that date gives an estimated expiration of Wednesday, November 11, 2026.
- With the 30-day reminder, the calculator tells you to schedule your next inspection or send an extension request by October 12, 2026.
If you live in a city with a different period, change the dropdown and the dates move with it. The result is still an estimate until your building department confirms it.
More questions
Does the clock start when I apply or when the permit is issued?
Under the model code, expiration counts from issuance. Applications that are never issued have their own 180-day abandonment rule, described above. Your city may count differently, so check the language on your permit.
My city's rule isn't a fixed number of days. Can I still use this?
Yes, as a rough guide. Enter the days between your issue date and the expiration date shown on your permit, and use the reminder to plan ahead. For cities with renewal windows, set the reminder so it lands inside that window.
