Boise's Zoning Overlays & Bonuses: The Rules That Matter

Every city handles zoning overlays & bonuses a little differently. In Boise, Idaho, there are 4 distinct rules that residents and property owners should be aware of. Some are stricter than what neighboring cities enforce, and others are more relaxed. Here is what you need to know.

Specific Plans Overview

Boise replaced its decades-old zoning ordinance with a Modern Zoning Code effective December 2023, simplifying districts, allowing more housing types by right, and aligning with Blueprint Boise comprehensive-plan goals.

Key details: Effective date: Dec 1, 2023. ADUs allowed: Most residential zones. Foothills overlay: Yes. Hearing body: Planning and Zoning.

Building or operating contrary to the new code triggers permit denial, stop-work orders, or daily civil penalties under Title 11 enforcement provisions.

Density Bonus Law

Boise's Modern Zoning Code offers density and height bonuses for projects that include income-restricted units, particularly along priority transit and growth corridors identified in Blueprint Boise.

Key details: Income target: ≤80% AMI. Bonus type: Height + density + parking. Mandatory IZ: Banned by ID §50-1929. TIF partner: CCDC.

Failure to record long-term affordability covenants triggers loss of the bonus and possible enforcement against the project's certificate of occupancy.

Boise is more permissive than most cities when it comes to density bonus law. That said, there are still limits.

Transit-Oriented Communities (TOC)

The Modern Zoning Code creates mixed-use corridor districts along Valley Regional Transit's high-frequency routes, enabling four-to-six-story residential and mixed-use buildings near State Street, Vista, and Fairview.

Key details: Lead corridor: State Street. Max height: Up to 6 stories. Parking minimums: Reduced/eliminated. Transit operator: Valley Regional Transit.

Projects that fail to meet corridor frontage and active-use standards can be denied design review approval or required to redesign before permit issuance.

Boise is more permissive than most cities when it comes to transit-oriented communities (toc). That said, there are still limits.

Hillside Overlay Rules

Development on slopes above 15% in Boise's Foothills triggers the Hillside and Foothills overlays, which restrict cuts, fills, building footprints, and landscape choices to protect viewsheds, wildfire safety, and the Boise Foothills Conservation Easement.

Key details: Trigger slope: ≥15% average. Geotech review: Required >25%. Trail dedication: Often required. Conservation partner: Land Trust Treasure Valley.

Grading or building outside approved hillside plans triggers stop-work orders, restoration requirements, and daily fines under Title 11. Repeat violations can void the development approval.

This is not one of those rules that cities tend to ignore. Boise actively enforces its hillside overlay rules requirements.

The Bottom Line

Compared to many U.S. cities, Boise gives residents more room on zoning overlays & bonuses. 2 of the 4 rules here are rated permissive. But permissive does not mean unregulated. There are still requirements, and the city does enforce them when violations are reported.

These rules come from Boise's publicly available municipal code. For complete penalty schedules, exemption details, and answers to common questions, see the individual ordinance pages throughout this guide.