Raising rent in a Washington mobile-home community: the 5% cap (2026)

Washington capped park rent in 2025 (House Bill 1217, effective May 7, 2025), and it treated manufactured-home communities more strictly than apartments: a flat 5%, no CPI math, and — unlike the apartment cap, which sunsets in 2040 — no expiration date written into the park section. Here's what a Washington park owner has to do right in 2026.

Part of our state-by-state series — lot rent increase rules by state. Other states: Texas · California · Florida · Oregon

The cap: a flat 5% (RCW 59.20.370)

Rent for a manufactured/mobile-home lot may rise at most 5% in any 12-month period. There's no inflation adjustment to compute and no annual percentage to look up — apartments got "7% + CPI up to 10%," parks got 5%, flat. And no increase of any size during the tenant's first 12 months — a freeze that applies whether the tenancy is month-to-month or a fixed-term lease.

The notice: three months, on the state's form

The park notice period is three months before the increase takes effect (RCW 59.20.090) — Washington's statute says "three months," not "90 days," and HB 1217 left the park period unchanged while moving apartments to 90 days. What HB 1217 did add is a required form: the notice must substantially match the statutory template — the rules, the 5% figure, any claimed exemption with supporting facts, the dollar amount and effective date — and the Department of Commerce publishes a model version specifically for manufactured-home lots. A friendly homemade letter that skips the required language is challengeable no matter how generous the timing.

The exemptions (RCW 59.20.380)

• Lots run by public housing authorities or qualifying nonprofits under other affordability programs.
• The first year after a "qualified sale" of the whole community to a resident cooperative or preservation buyer, with homeowner approval.
• The home-sale reset: when a tenant sells their home and the lot lease transfers, the landlord may take a one-time increase of any size at that lease's first renewal — but only if the option was disclosed before the transfer closed.

What getting it wrong costs

A tenant hit with an unlawful increase can demand a cure and, if refused, walk with 30 days' notice owing nothing past the vacate month. In court, the owner faces the excess rent back, up to three months of the unlawful amount in damages, and attorney's fees — and the Attorney General can sue independently with civil penalties up to $7,500 per violation. HB 1217 also capped park move-in charges (deposit plus fees at one month's rent, two with pets) and late fees (2%, then 3%, then 5% of monthly rent for consecutive late months) — worth re-checking your fee schedule while you're at it.

Common Washington mistakes

• Using the general apartment notice form instead of the manufactured-home-lot version
• Applying "7% + CPI" math to a park — the park cap is a flat 5%
• Raising rent inside a tenant's first 12 months, including on fixed-term leases
• Taking the home-sale reset without having disclosed it before the transfer
• Sending a plain letter without the required statutory language

Run your number through the free lot rent increase calculator (it applies the 5% cap and rounds down), then draft with the notice generator and adapt it to the Commerce model form. The two-state picture is in Oregon and Washington rent caps for 2026.

Sources

• RCW 59.20.370 (the 5% cap): https://app.leg.wa.gov/RCW/default.aspx?cite=59.20.370
• RCW 59.20.380 (exemptions): https://app.leg.wa.gov/RCW/default.aspx?cite=59.20.380
• RCW 59.20.390 (required notice form): https://app.leg.wa.gov/RCW/default.aspx?cite=59.20.390
• WA Dept. of Commerce, HB 1217 landlord resource center (model forms): https://www.commerce.wa.gov/housing-policy/hb1217-landlord-resource-center/
• EHB 1217 final bill report: https://lawfilesext.leg.wa.gov/biennium/2025-26/Pdf/Bill%20Reports/House/1217.E%20HBR%20FBR%2025.pdf

General information, not legal advice. HB 1217 is new law and agency guidance is still evolving — confirm the current form and figures with the Department of Commerce before you send.