Issaquah, WA Solar Energy: Panel Permits (2026)

Item 26 of the building list in section 105.2 of the Construction Administrative Code (IMC 16.04.010) applies only to PV systems designed for a detached one- or two-family dwelling or townhouse not more than three stories above grade, or a detached accessory structure. Every criterion must be met. The system must be installed by a licensed contractor, with an engineered mounting system designed for PV, on a roof made from lightweight material such as a single layer of composition shingles, metal roofing or cedar shingles.

The physical limits are numeric. Panels are mounted no higher than 18 inches above the roofing surface, and except on flat roofs no portion of the system exceeds the highest point of the roof or ridge. Total dead load of panels, supports, mountings, raceways and all other appurtenances weighs no more than 4.0 pounds per square foot, and supports spread the load across as many roof-framing members as needed so that no point carries a load over 50 pounds. Roof and wall penetrations must be flashed and sealed, the installation must follow the manufacturer's instructions, and the system must comply with International Residential Code Section R324. Roof-mounted collectors and supports must be noncombustible or fire-retardant-treated wood equivalent to that required for the roof construction.

The home must be code compliant to setbacks and height, or the code must allow expansion of a nonconformity for solar panels. The last criterion, m, requires that the PV system has an approved and issued electrical permit, so the exemption removes the building permit and not the electrical one.

Section 105.2 also excludes areas of flood hazard and City land use critical areas from every exemption unless the work is entirely within or on the exterior envelope of a legally established existing building. IMC 16.04.020 separately adopts IRC Appendix T, Solar-Ready Provisions, and section 107.2.12 requires electrical plans to be submitted when the Building Official determines they are needed to show compliance.