Walla Walla County, WA Solar Energy: Panel Permits (2026)

Walla Walla County Code § 3.08.220 sets separate flat fees for residential solar installations rather than pricing them off project valuation like most other building work. A ground-mounted residential array costs a $75.00 application fee plus a $205.00 permit fee, plan review fee, and $80.00 for each inspection beyond the first two. A roof-mounted residential array costs the same $75.00 application fee but only a $155.00 permit fee, plus the same plan review and per-inspection charges. Commercial and nonresidential solar arrays are not flat-fee; they are billed off project cost or building valuation using the county's standard valuation fee scale instead.

These fees sit inside the county's adopted State Building Code chapter, Section 15.04.030, which pulls in the International Building Code, International Residential Code, International Mechanical Code, International Fire Code, Uniform Plumbing Code and the Washington State Energy Code by reference for all unincorporated-area construction, including solar installations. Because a solar array is treated as building work under this chapter, it needs a Community Development plan review and permit before panels go up, not just a utility interconnection agreement. Applicants pay the $75 application fee at submittal, with the balance due before the permit issues, and any inspection beyond the two included in the base fee is billed separately at $80.00 each.