State Zoning Preemption Wave 2026: What It Means for Your Market and Your Deal Flow

In the span of seven years, a fundamental reallocation of zoning authority has shifted control from city halls to state capitals across a growing number of jurisdictions. What began as a handful of housing-cost-crisis responses in coastal states has become a bipartisan legislative movement that now reaches into New England, the Mountain West, and the Sun Belt simultaneously. The practical consequence for independent landlords is not a simple "more supply" or "less competition" calculus. It is a market-specific, jurisdiction-by-jurisdiction reassessment of what a property is worth, what it can become, and who is competing to buy or rent it.

State governments did not begin overriding local zoning out of ideological conviction alone. The trigger was structural: housing costs in large metro areas had reached levels that were visibly suppressing labor mobility, economic growth, and political stability. When median rents in Austin, Phoenix, and Denver began consuming 40 to 50 percent of median household income, state legislators faced pressure from both employers and constituents to act. Local governments, many of them controlled by existing homeowner coalitions with strong incentives to preserve housing scarcity, had proven unwilling or unable to reform their own zoning codes at the pace the crisis demanded. Preemption became the legislative workaround.

The Legislative Landscape

The most cited inflection point is Oregon HB 2001, signed into law in June 2019. Oregon became the first state in the country to eliminate single-family-only zoning statewide, requiring all cities with more than 10,000 residents to allow duplexes on any lot that permitted single-family homes. The law did not mandate duplex construction, but it removed the legal barrier that had kept duplexes illegal on the majority of residential land in the state. Per the Oregon Department of Land Conservation and Development's 2022 implementation report, more than 60 percent of the affected jurisdictions had adopted compliant zoning code updates by the end of 2021, unlocking duplex development rights on tens of thousands of parcels across Portland, Eugene, Salem, and smaller cities.

Montana HB 245, passed in 2023, extended the same logic further into smaller markets. The law required every city with more than 5,000 residents to permit duplexes on any lot zoned for residential use, regardless of local plan designations or historic preservation overlays. Montana's reform was notable for two reasons: it passed in a state with a Republican-controlled legislature and a Republican governor, and it targeted small cities that had largely escaped the coastal housing affordability debate. Helena, Missoula, and Bozeman were the obvious beneficiaries, but the law also applied to places like Kalispell, Havre, and Miles City, where rental vacancy rates had tightened to below 3 percent.

California SB 9, effective in 2022, went further than either Oregon or Montana by allowing both duplexes and urban lot splits statewide. A single-family lot owner in San Francisco or Los Angeles could now subdivide and build two units, effectively doubling the development potential of land that local zoning had restricted for decades. Per the California Department of Housing and Community Development's 2023 housing progress report, permit applications for duplex and multi-unit projects in affected jurisdictions increased by 34 percent in the first year following SB 9 implementation, though actual construction starts lagged permit filings by 12 to 18 months on average.

Florida and Texas have moved on parallel but distinct tracks. Florida's Live Local Act, passed in 2023, prohibited local governments from denying multi-family development on any parcel zoned for commercial or industrial use if the development included affordable units. The law effectively bypassed the residential permitting process for mixed-income projects in commercial corridors. Texas's 2025 housing package (including HB 24) took a similar approach, reforming municipal minimum lot-size requirements for single-family homes and barring density restrictions that prevented ADU construction — confirm the specific figures in the enrolled bill text. Neither law is as sweeping as Oregon's or California's, but both represent a deliberate state-level decision to override local preferences for lower-density residential development.

Arizona's 2024 occupancy-limit reform prohibited cities and counties from enforcing occupancy limits of fewer than three adults per bedroom in any residential unit (the specific bill number is pending verification), directly attacking a tool that many municipalities had used to suppress multi-generational households and roommate living arrangements. The law's practical effect was to increase the effective demand for any given unit by making larger households legally permissible where they had previously been prohibited.

New Hampshire's 2026 legislative session produced a cluster of zoning and housing reform bills that NH RE Partners covered extensively in its Q2 2026 market report. Legislation signed in June 2026 established a state-level right to ADU construction, prohibiting municipalities from banning accessory dwelling units on any lot with an existing single-family home, regardless of local zoning district designation. A companion bill established a streamlined permitting process for multi-family projects in municipalities with fewer than 5,000 residents, removing the local variance requirement that had previously given Planning Board members de facto veto power over apartment construction in small towns. Per housing-policy reporting, roughly ten states have adopted some form of ADU preemption legislation since 2021, including New Hampshire.

Why This Cycle Is Different

The 2019 to 2024 wave of state zoning reforms shared a common feature: it was concentrated in states with acute housing affordability crises and Democratic-controlled legislatures. Oregon, California, and Colorado passed the most aggressive reforms, and the political logic was straightforward. Dense housing in cities was expensive, young voters were leaving high-cost metros, and the housing shortage had become a visible campaign issue.

The 2025 to 2026 wave looks different. It is bipartisan. Montana, Florida, Texas, and Arizona all have Republican-controlled legislatures. New Hampshire's 2026 ADU and permitting reforms passed with bipartisan support in a state where the political economy of land use is more about economic development than ideological housing philosophy. Recent zoning reforms show a bipartisan pattern — states with Republican-controlled legislatures and states with Democratic-controlled legislatures have both passed major preemption legislation in 2025 and 2026. The ideological composition of the legislature is no longer a reliable predictor of whether a state will preempt local zoning.

What is driving bipartisan agreement is economic. Labor mobility has become an explicit economic development concern. Businesses in secondary markets — Boise, Huntsville, Asheville, Manchester — are reporting difficulty recruiting workers who cannot find affordable housing within a reasonable commuting distance. State chambers of commerce have become effective advocates for zoning reform because the housing shortage is now visible in help-wanted ads, not just in housing statistics. This economic framing has made preemption politically viable in legislatures that would have rejected it as a local-government overreach issue five years ago.

What It Means for Your Market

The impact on any given rental market depends on three variables: the current zoning baseline, the supply elasticity of new construction, and the pace of permit issuance after preemption takes effect.

In markets where local zoning was already relatively permissive — many Texas and Florida metros, for example — state preemption changes less. If duplexes were already allowed by right on most residential lots, the legal change does not unlock new supply; it merely removes a potential political obstacle. The practical impact is modest.

In markets where local zoning was highly restrictive — coastal California, parts of New Hampshire, suburban Portland — the impact can be substantial. When duplex rights are restored to land that legally could not hold duplexes the day before, the development potential of every residential parcel increases. This changes land prices, because developers are now willing to pay more for lots that have a duplex as-of-right. It also increases competition for those lots, because the buyer pool expands from owner-occupants to include developers and investors who were previously excluded by zoning.

For rental markets specifically, the ADU preemption laws are the most directly relevant. In New Hampshire, the 2026 ADU legislation means that any single-family lot in the state can now legally host an ADU. The question is whether that legal right translates into actual units. In markets with high construction costs, constrained contractor availability, and long permit queues, the gap between legal right and built unit can be five to ten years. In California — the state with the most mature ADU preemption framework — ADU permit issuance has grown sharply since 2021, while construction completions lag permit issuances significantly due to contractor shortages and material cost volatility.

The rental market pressure effect is also market-specific. In markets where preemption unlocks ADU construction on a large scale, the incremental supply of small rental units — typically one- and two-bedroom ADUs — puts downward pressure on rents for those unit types. In a market like Portland or Sacramento, where ADU pipeline is strong, the competing supply effect is real. In a rural New Hampshire market where construction costs are high and the skilled trades workforce is small, the incremental supply effect may be too small to register in rents within a two- to three-year horizon.

Underwriting Implications

Independent landlords who acquired properties in jurisdictions that were subject to restrictive local zoning face a specific analytical question: what is the property worth if its legal use expands?

The straightforward answer is: more. A single-family home on a lot that legally allows an ADU is worth more than an otherwise identical home on a lot that does not, because the ADU adds an income-producing unit that can be rented at market rates. But the actual value uplift depends on whether the physical and economic conditions support ADU construction. A steep lot, a home with a small setback nonconformity, a property in a flood plain, or a municipality with slow permit processing can all make ADU construction economically marginal even where it is legally permitted.

The more subtle underwriting question is the reverse case: what happens to a market when a neighboring jurisdiction gets preempted and starts building more units? If the two jurisdictions serve the same rental market — meaning tenants view them as substitutes — then new supply in Jurisdiction B increases competition for tenants in Jurisdiction A. This is the spillover effect that single-market underwriting often misses. A landlord underwriting a property in a town that has maintained restrictive zoning should be aware that if the adjacent city gets preempted and starts producing new units, those units may compete for the same tenant pool.

For existing properties, the ADU preemption laws create a specific due-diligence item that was previously unnecessary: an assessment of whether an ADU is physically and economically viable on the subject property. Lot size, setback dimensions, impervious surface coverage limits, and septic system capacity are all facts that can prevent ADU construction even where state law now permits it. A property that looks like it gained ADU optionality under the new law may still be effectively constrained by physical conditions that make ADU construction impractical.

Deal Flow and Competition Effects

The competition effects of state zoning preemption on deal flow run in two directions simultaneously, and they do not cancel out.

More units competing for tenants is the effect that landlords tend to focus on, and it is real in markets where the ADU and duplex pipeline is large. In California's Inland markets, the ramp-up in ADU completions is creating competitive pressure on rents and vacancy in segments of the market that had been extremely tight. This is not a crisis, but it is a measurable softening.

More demand from population growth is the countervailing effect, and it is more durable. Preemption laws are most aggressively enacted in markets that are growing. The political will to override local zoning rarely exists in markets that are shrinking or static. Austin, Phoenix, Boise, and Salt Lake City are all growing markets where preemption laws are enabling more construction. The net effect in those markets is more units AND more people competing for those units, which tends to support rents rather than suppress them, at least in the near to medium term.

The independent landlord's practical concern is not the aggregate market effect but the micro-market specific effect: what is happening in the specific zip code and property type that defines a given investment. A landlord holding a two-bedroom single-family home in a suburb that just got duplex preemption faces different competitive dynamics than a landlord holding a four-unit building in a downtown core that already allowed multi-family construction. Treat every market as a specific case, not a category.

Five-Minute Action Items

1. Pull the zoning records for every property in the portfolio. Confirm whether the jurisdiction governing each property has been subject to state preemption legislation since 2021. The Housing Affordability Institute's 2026 tracker is a useful starting point, but the definitive source is the current municipal zoning ordinance as actually enforced. A phone call to the municipal planning office takes five minutes and resolves ambiguity that online records cannot.
2. Assess ADU viability for every single-family lot in the portfolio. For each property, note: lot size, setback dimensions, impervious surface coverage, septic or sewer capacity, and any known nonconformances. Properties where ADU construction is physically viable represent an option that has become more valuable under the new state laws. Properties where ADU construction is physically constrained are worth revisiting under the lens of potential legislative further reform.
3. Identify adjacent jurisdictions that may have been preempted. A competitor property in an adjacent town that now legally allows duplexes or ADUs may be planning to add units that will compete for the same tenant pool. This is a five-minute geographic scan: list every jurisdiction within a 10-mile radius, check the Housing Affordability Institute tracker for preemption status in each, and note which ones have active permit pipelines.
4. Adjust comparable rent analysis for ADU pipeline. In markets where ADU construction is ramping up — California and New Hampshire are the clearest examples right now — the comparable rent data should be segmented between traditional single-family units and ADU units. ADUs typically rent at a discount to equivalent traditional units, which means that if the ADU pipeline is large, it may be compressing rents at the lower end of the market in ways that blended comparable analysis will miss.

SOURCES: Oregon HB 2001 (2019); Montana HB 245 (2023); California SB 9 (2021); New Hampshire 2026 ADU and housing-permitting reforms; Florida Live Local Act (2023); Texas 2025 housing package (e.g., HB 24); Arizona 2024 occupancy-limit reform; Housing Affordability Initiative State Legislatures and Housing Reform 2026 tracker; NH RE Partners Q2 2026 market report; Housing Affordability Initiative "The States That Said No to Local Veto Power" (March 2026); Oregon Department of Land Conservation and Development 2022 implementation report; California Department of Housing and Community Development 2023 housing progress report; California Apartment Association 2025 market report.