How long is a building permit valid for?

A building permit lapses if substantial construction has not occurred within 6 months (180 days) following the approval of the permit. If an extension is required, the applicant should meet with the Building Official in advance of the expiration date to discuss the possibility of an extension. Some of the reasons for an extension are health, personal, or possibly a modification of the work. All permits laps after 3 years even if the work has not been finalized. Another permit must be issued to complete the remainder of the work.