Senate Bill 532, introduced in the Montana Legislature on March 18, 2025, aims to revise county zoning laws to facilitate the creation of accessory dwelling units (ADUs) across the state. The bill, sponsored by Senators F. Mandeville, D. Zolnikov, J. Fuller, C. Glimm, G. Hertz, and K. Bogner, seeks to address housing shortages and promote more flexible living arrangements within existing residential areas.

The key provisions of SB 532 mandate that counties allow at least one ADU by right on any lot containing a single-family dwelling. These units can be attached, detached, or internal to the primary residence, with size restrictions set at a maximum of 75% of the main dwelling's gross floor area or 1,000 square feet, whichever is smaller. The bill also prohibits counties from imposing certain regulations that could hinder the development of ADUs, such as requiring additional parking, matching architectural styles, or mandating owner occupancy.

Debate surrounding the bill has highlighted concerns about potential impacts on neighborhood character and infrastructure. Opponents argue that allowing ADUs without stringent regulations could lead to overcrowding and strain local resources. Proponents, however, emphasize the need for affordable housing options and the benefits of increased density in urban areas.

The economic implications of SB 532 could be significant, as it may encourage property owners to create rental units, thereby increasing housing availability and potentially stabilizing rental prices. Socially, the bill could provide more flexible living arrangements for families, elderly residents, and individuals seeking affordable housing solutions.

As the bill progresses through the legislative process, its future remains uncertain. Supporters are optimistic about its potential to alleviate housing shortages, while critics continue to voice concerns about its impact on community dynamics. The outcome of SB 532 could set a precedent for how Montana addresses housing challenges in the coming years.