Ada County, ID Sign Regulations: Digital Billboards (2026)

County Code Section 8-3-12(K) sets the standards for billboards in unincorporated Ada County, including electronic message boards and animated displays. Billboards are principal permitted uses in Commercial and Industrial base districts, but are prohibited in transitional districts, LO and CI, and are not allowed at all in Residential, Transitional, C1 or LO districts under Table 8-3-12-12. Where allowed, a billboard may not exceed 650 square feet of sign area, with a maximum height of 50 feet in Rural districts and 40 feet in Commercial and Industrial districts.

Animated or electronic message content, which the code separately defines as a freestanding sign with changeable copy provided by a digital readout, is capped at 20% of the sign area regardless of district. Billboards must also sit at least 750 feet from any other billboard, measured center-to-center of the support structure, and may not stand closer than 50 feet to property zoned R4, R6 or R8 or within 150 feet of a detached single-family home. A billboard cannot be built on a roof, and if built over a roof it needs at least 10 feet of clearance to the lowest point of the display.

highway, Idaho state highway, or a street classed as an arterial on the County's Master Street Map; scenic byway corridors and other street classifications are off-limits. A Sign Plan is one of the applications the Director of Development Services can approve administratively under Section 8-9-4(C)(11), without a public hearing, but any digital billboard proposal still has to clear this permitting step before installation.