They’re known by many names – backyard cottages, in-law suites, granny flats, mother-in-law apartments, guest homes, casitas – but building codes don’t have cutesy names for them. They’re designated as “accessory dwelling units,” or ADUs.

No matter what they’re called, we expect to see more of them in the coming years.

The state Legislature passed a law this year to expand housing options by easing barriers to building and using ADUs, citing a statewide housing affordability crisis.

Not everyone can afford to buy a house in the Tri-Cities when the median home price is more than $400,000. And not everyone can afford to rent an apartment when the average monthly cost is $1,320.

Benton and Franklin counties added nearly 5,000 people in the past year for a total population of nearly 317,000, and the region continues to grow at a faster clip than the state average. All these people need a place to live.

ADUs, which are built on the same lots as single-family homes, can provide lower-cost options for renters and owners. They can allow elderly family members to age at home, or young adults struggling to find an affordable first home to gain a foothold as they join the workforce.

Our new state ADU law doesn’t require cities and counties to update their building codes immediately – they can tackle them when they update their comprehensive plans – but we’re encouraged to see the Tri-Cities are already beginning this work.

Pasco is taking the lead, revising its code in early 2022. The public’s enthusiastic response proves the changes were needed and wanted. The city has received 41 applications for ADUs since its code update and reported brochures outlining the new code were “flying off the shelves.”

Kennewick could begin public hearings on ADU code changes as early as this fall, with its new code rolling out next year. Richland and West Richland won’t be far behind, as their next comprehensive plan updates are scheduled for 2026.

We expect to see more of these pint-size homes pop up around the Tri-Cities. ADUs won’t solve the affordable housing crisis but they’re certainly a good place to start.