Igni
Montana · MTCoverage expanding

Montana residential & ADU permit data

Statewide housing reform in the fast-growing Mountain West

We're expanding to Montana. Subscribe to be notified when it goes live.

Housing law

Montana's SB 528 (2023, effective 2024) requires municipalities statewide to allow at least one accessory dwelling unit by right on lots with a single-family home; the state's 2023 housing-reform laws were upheld by the Montana Supreme Court in 2026.

SB 323 (2023) requires cities of 5,000 or more to allow duplexes on lots where single-family homes are permitted, with no stricter standards than for single-family homes.

SB 528 — statewide ADUs (2023)SB 323 — duplexes in cities 5,000+ (2023)

Major permit jurisdictions

BillingsMissoulaBozeman

Why Igni for Montana

One of the fastest-growing housing markets in the Mountain West

Track new statewide ADU and middle-housing permits as reform rolls out

Request priority coverage and we'll notify you when Montana goes live

Start tracking Montana permits

Fresh, filterable residential and ADU permit leads — delivered before your competitors even know.

Permit data via municipal open-data portals and public records where available.

Informational only, not legal advice. Housing law changes — verify current statutes before relying on this.