Seattle Home Values

If you live in the City of Seattle, you’ve probably heard about the Accessory Dwelling Unit bill that the City passed earlier this year. You might be curious, can I add an ADU on my property? How? How much is it going to cost me? Will it be a good investment? This article breaks down the new requirements for Accessory Dwelling Units, walks through the steps to build one, and answers your questions on whether you should consider this latest development in urban living for your property.

Can I build an ADU?

First, Accessory Dwelling Units come in two flavors: attached (ADU’s) and detached (DADU’s). What’s the difference? Simple – an ADU is physically attached to the primary dwelling, and a DADU is separated (by at least 5 feet, per code).

Second, yes: If you live in a house in the City of Seattle, you can add an Accessory Dwelling Unit (provided you physically have the space to do so).

How do I build a DADU?

Creating a legal Accessory Dwelling Unit requires a building permit in Seattle, no exceptions (even if you’re just converting an existing basement into a rental space). What qualifies as an Accessory Dwelling Unit? A kitchen – A house with two kitchens will always be viewed as two dwelling units, and needs to be permitted as such. Want to cordon off a couple rooms and rent them out? Feel free, as long as they are accessible from within the unit and don’t have their own kitchen (and you’re comfortable claiming your renters as members of your household and to operate within this gray area of the law).

Here are the steps to build an ADU: