Wash. Rev. Code § 64.38.055
(1) The governing documents may not prohibit the installation of a solar energy panel by an owner or resident on the owner's or resident's property as long as the solar energy panel:
(2) The governing documents may:
(b) Permit the attachment of a solar energy panel to the slope of a roof facing a street only if:
(c) Require:
(4) For purposes of this section, "solar energy panel" means a panel device or system or combination of panel devices or systems that relies on direct sunlight as an energy source, including a panel device or system or combination of panel devices or systems that collects sunlight for use in:
[ 2009 c 51 s 1.]