This bill amends the residential landlord-tenant act and the manufactured/mobile home landlord-tenant act in Washington State to impose new regulations on residential rent increases. It prohibits landlords from raising rent during the first 12 months of a tenancy and limits annual rent increases to the greater of the rate of inflation as measured by the consumer price index or three percent, with a maximum increase of seven percent. Landlords are required to provide written notice of any rent increase, including justification for any exemptions claimed. Tenants charged unlawful rent increases can seek damages, including punitive damages and attorney fees.

Additionally, the bill outlines specific exemptions that allow landlords to exceed the established rent increase limits, such as for properties with a certificate of occupancy issued within the last ten years, federally funded properties, or significant improvements made to rental units. It introduces a "banked capacity" program, enabling landlords to accumulate unused rent increase capacity for future years. The Department of Commerce will calculate and publish the maximum allowable rent increase percentage annually, and landlords must inform tenants about potential future rent increases and their rights under this law. The bill emphasizes the importance of these changes for public peace, health, or safety, and takes effect immediately upon passage.