Owners of manufactured home communities in Washington state have launched a legal challenge seeking to block implementation of a recently enacted rent cap law that limits annual increases for lot rents to five per cent, arguing the policy is unconstitutional and unworkable.

The lawsuit, filed in Spokane County Superior Court by the Manufactured Housing Communities of Washington, contends that the statute — part of landmark rent stabilization legislation that took effect in May last year — imposes undue financial strain on park owners by preventing them from raising rents above the statutory ceiling even amidst rising costs and emergencies.

The plaintiffs argue the law lacks a mechanism for exemptions or hardship adjustments and assert it violated property rights by effectively altering existing lease terms without due process.

House Bill 1217, signed into law in May by Governor Bob Ferguson, set an annual cap on rent increases for residents who own their manufactured homes but lease the land beneath them, restricting landlords to a maximum five per cent rent rise each year and barring any increase during the first year of tenancy.

Supporters of the law framed it as an historic measure to bring stability and predictability to vulnerable tenants, many of whom are seniors or low-income families, who previously faced unpredictable and steep rent hikes that threatened their ability to remain housed.

The statute also includes broader rent stabilization measures for traditional residential tenancies.

In their eight-page complaint, park owners maintain that the absence of a hardship exception leaves landlords without recourse even when confronted with unexpected infrastructure failures or sharply rising maintenance costs.

They further argue that exempting certain entities, such as public housing authorities and nonprofit organisations, while subjecting others to the cap, creates an unequal, two-tier regulatory system that violates constitutional protections.

The organisation has asked the court to halt enforcement of the rent limit while the legal challenge proceeds.

The state’s Attorney General’s Office, representing Washington in the case, has signalled its intention to defend the law vigorously, expressing confidence that the statute will be upheld.

No court dates have yet been scheduled.

The legal dispute underscores the broader tensions between efforts to ensure housing affordability and the financial viability concerns of property owners at a time when housing costs and operating expenses continue to rise across the state.