Summary of Middleton Ordinance 715 (March 2026) · ADU 800 sqft / 50% primary cap; detached second dwellings can receive separate street addresses; ETZ parcels capped at 500 sqft under Canyon County overlay as it applies in Middleton. Reference: https://library.municode.com/id/middleton.
Code evolves continuously. Verify at the official source (https://library.municode.com/id/middleton) before any development decision.
Applicable code
Code references active as of publication. Verify current standards at the official source before any development decision.
Accessory dwelling units shall not exceed 800 square feet or 50% of the primary dwelling's finished square footage, whichever is less.
Investor implication: Size cap limits ADU rental income potential but enables faster permitting and lower construction costs compared to full second-unit builds. 800 sq ft ceiling applies regardless of primary dwelling size.
Verify at City of Middleton Municipal Code →Detached accessory dwelling units may receive separate street addresses when they meet fire code separation requirements and utility service standards.
Investor implication: Separate addressing enables independent utility metering, simplifies long-term rental management, and supports future lot-split scenarios. Verify fire separation distance (typically 10 feet) and utility tap capacity before design.
Verify at City of Middleton Municipal Code →Parcels within Middleton's Extraterritorial Zoning (ETZ) area under Canyon County jurisdiction are limited to 500 square feet maximum for accessory dwelling units.
Investor implication: ETZ parcels face a 300 sq ft reduction in maximum ADU size compared to city-limits properties. This materially impacts rental income potential and construction feasibility. Verify ETZ boundary status before acquisition. Note: This restriction applies to parcels within Middleton's Area of Impact under Canyon County jurisdiction; verify jurisdictional status with Middleton Planning & Zoning.
Verify at City of Middleton Municipal Code →Cities with populations over 10,000 must allow at least one accessory dwelling unit per residential lot. Owner-occupancy requirements are prohibited. Blanket square-footage bans are prohibited. HOAs cannot add new ADU restrictions without written consent of all members.
Investor implication: State law guarantees ADU permissibility in Middleton regardless of local resistance. Existing HOA covenants recorded before July 1, 2026 remain enforceable, but new restrictions cannot be added. Verify HOA CC&Rs for pre-existing ADU bans before acquisition.
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