Amends GS 143-138(b5), concerning the permitting exception set out for any construction, installation, repair, replacement, or alteration performed in accordance with the current NC State Building Code in any single family residence or farm building that does not exceed a cost threshold, currently set at $15,000. Gradually increases the cost threshold for the exception by $1,000 every October 1 from 2021 through 2025, with the threshold set at $20,000 on October 1, 2025. Maintains specified construction, installation, repairs, replacement, or alterations that require permitting under the Code or local ordinance.