Is Idaho a Dillon's Rule or home rule state for zoning?

Idaho is a Dillon's Rule state. Despite constitutional language in Article 12, Section 2 that appears to grant cities broad powers, Idaho courts have held that municipalities may exercise only powers expressly granted by the legislature, chiefly through the Local Land Use Planning Act (Idaho Code Title 67, Chapter 65).

Can I build an ADU in Idaho?

It depends entirely on the city — Idaho has no statewide law requiring cities to allow ADUs. Boise's 2023 zoning code rewrite eased ADU and infill standards inside city limits, but rules vary widely elsewhere in the state, and some smaller cities and counties don't address ADUs at all.

Do Idaho cities require a comprehensive plan before zoning?

Yes. The Local Land Use Planning Act requires every city and county that adopts zoning to first adopt a comprehensive plan addressing land use, population, and public services, and zoning ordinances must be consistent with that plan.

How do I find zoning for a parcel in Idaho?

Idaho has no unified statewide parcel-zoning portal. Each city or county planning department publishes its own zoning map (e.g., Boise's Development Code map or Meridian's UDC map), and the University of Idaho's INSIDE Idaho GIS clearinghouse aggregates county layers where counties have submitted them.

Idaho · state zoning reference · Parcel data · lookup only

Idaho zoning: how it works and what you can build

Idaho courts apply Dillon's Rule to strictly limit city and county zoning power under the Local Land Use Planning Act, and with no statewide ADU mandate on the books, accessory dwelling unit rules in the booming Boise and Coeur d'Alene metros are set entirely city by city.

How zoning works in Idaho

Idaho is a Dillon's Rule state in practice: although Article 12, Section 2 of the Idaho Constitution grants cities broad-sounding home-rule-style language, Idaho courts have consistently held that municipalities may exercise only powers expressly granted by the legislature (or necessarily implied from an express grant). The controlling statutory framework is the Local Land Use Planning Act (Idaho Code Title 67, Chapter 65), which requires every city and county that adopts zoning to first adopt a comprehensive plan, and which sets statutory notice-and-hearing procedures for zoning ordinance and map amendments. Cities and counties commonly form joint plan commissions in fast-growing areas, and county zoning fills in unincorporated territory outside city limits.

Unlike several neighboring growth states, Idaho has no statewide law requiring cities to allow accessory dwelling units or other missing-middle housing types — ADU policy is set entirely at the city level, so feasibility varies widely by jurisdiction. Boise has moved on its own: the city completed its first full zoning code rewrite since 1966 in 2023, reorganizing the Boise Development Code and easing infill and ADU standards inside city limits.

For developers, this means Idaho's zoning landscape is bifurcated: modernized, growth-oriented development codes in the Boise and Coeur d'Alene metros contrast with more basic, lower-capacity zoning administration in Idaho's smaller rural counties.

Who holds the zoning power

Land-use authority in Idaho is delegated by statute, not assumed — these are the acts a zoning ordinance in Idaho has to trace back to.

Local Land Use Planning Act Idaho Code Title 67, Chapter 65: Primary enabling framework requiring comprehensive plans and authorizing city and county zoning ordinances

Major cities and their codes

The enabling act sets the ceiling; the municipal code is what a project is actually reviewed against. The 7 largest Idaho jurisdictions and the codes they administer:

Idaho — municipal zoning codes
City	Zoning code
Boise	Boise Development Code, Title 11 (Boise City Code) Idaho's capital and largest city; completed its first full zoning code rewrite since 1966 in 2023
Meridian	Unified Development Code (UDC), Title 11, Meridian City Code Idaho's fastest-growing city, dominated by new-build suburban residential
Nampa	Nampa Zoning Ordinance Canyon County's largest city, with ongoing agricultural-to-residential conversion pressure
Idaho Falls	Idaho Falls Zoning Ordinance Eastern Idaho's commercial and medical hub
Pocatello	Pocatello Zoning Ordinance Southeastern Idaho university and rail city
Caldwell	Caldwell Zoning Ordinance Canyon County growth corridor along the Boise-Nampa-Caldwell axis
Coeur d'Alene	Coeur d'Alene Zoning Ordinance North Idaho lakefront resort market with active height and view-corridor restrictions

Recent reforms

State-level changes override or preempt what a local ordinance says — these are the Idaho reforms that move the numbers on a real site.

2023 Boise Zoning Code Rewrite Boise adopted its first complete zoning code overhaul since 1966, reorganizing the city into new zoning districts

Parcel & GIS data

Idaho has no unified statewide parcel portal; the University of Idaho's INSIDE Idaho GIS clearinghouse aggregates county-submitted parcel and zoning layers, though coverage and currency vary by county.

Real parcel geometry is already loaded for Nampa — see the zoning-by-city section above for a live district-and-parcel lookup there. That is not the same as a cited feasibility report: Chicago is still the only jurisdiction with bulk standards, § citations and a generated massing scheme.

Zoning by city

The statute sets who may zone; the city's own code sets what you can build. One guide per Idaho city below, explaining the district codes that appear on its zoning map — 95 district codes across Idaho so far.

Idaho zoning — common questions

Is Idaho a Dillon's Rule or home rule state for zoning?: Idaho is a Dillon's Rule state. Despite constitutional language in Article 12, Section 2 that appears to grant cities broad powers, Idaho courts have held that municipalities may exercise only powers expressly granted by the legislature, chiefly through the Local Land Use Planning Act (Idaho Code Title 67, Chapter 65).
Can I build an ADU in Idaho?: It depends entirely on the city — Idaho has no statewide law requiring cities to allow ADUs. Boise's 2023 zoning code rewrite eased ADU and infill standards inside city limits, but rules vary widely elsewhere in the state, and some smaller cities and counties don't address ADUs at all.
Do Idaho cities require a comprehensive plan before zoning?: Yes. The Local Land Use Planning Act requires every city and county that adopts zoning to first adopt a comprehensive plan addressing land use, population, and public services, and zoning ordinances must be consistent with that plan.
How do I find zoning for a parcel in Idaho?: Idaho has no unified statewide parcel-zoning portal. Each city or county planning department publishes its own zoning map (e.g., Boise's Development Code map or Meridian's UDC map), and the University of Idaho's INSIDE Idaho GIS clearinghouse aggregates county layers where counties have submitted them.

Working in Idaho? Get on the list.

The parcel layer lands in the order demand does. Illinois went first because that's where the deals were; the next state is decided by who tells us what they're trying to underwrite. Tell us where you're building and what you wanted to run — you'll hear from us when Idaho opens, and sooner if we need a test parcel.

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Want to see the finished shape of this work? Illinois is live at parcel level — Illinois zoning and the 53-district Chicago reference.

Idaho zoning summaries on this page are provided for information, not legal advice. Confirm every project against the current adopted code for the jurisdiction and the statute as amended.