Infill Development in Boise
Small-format new build on large post-war lots. ZOA25-000013 (2026) permits 2 ADUs per lot up to 900 sq ft. Idaho SB 1352 expands compact-lot density at 12 units per acre on 4+ acre tracts effective July 2026.
Market snapshot
Infill Development in Boise by the numbers. Sourced and dated.
Every figure carries source, date, geography, and confidence. Click through to verify any single data point.
Risks & constraints
Where the floor is. And what to verify.
Named risk patterns for this asset class. Underwrite against them.
Historic Overlay Interaction
Infill projects in Boise's historic districts (North End, East End) face design review requirements and material restrictions that extend timelines and increase architectural costs; verify overlay status and Design Review Board jurisdiction before acquisition.
ADU Utility Hookup Cost
ADU projects require separate utility connections (water, sewer, electric) with fees ranging from minimal tap charges to full impact fees depending on existing infrastructure capacity; budget $15K–$40K for utility hookups in older neighborhoods where system upgrades are required.
Parcel Assemblage Complexity
Infill projects requiring assemblage of multiple parcels face title defects, seller coordination delays, and financing gaps; single-parcel plays eliminate assemblage risk and compress acquisition timelines.
Idaho SB 1354/1352 Transition
Idaho's new starter-home density laws (SB 1354, SB 1352) effective July 1, 2026, preempt local restrictions on smaller homes, but local implementation timelines and interpretation vary; verify that Boise's Title 11 updates align with state mandates before relying on density allowances in underwriting.
Entitlement Timeline Uncertainty
PLD (Planned Land Development) and use-permit reviews in Boise carry variable timelines depending on neighborhood opposition, Planning & Zoning Commission workload, and staff capacity; budget 90–180 days for entitlement on contested projects.