ADU type
Attached ADU and Home Additions
An attached ADU shares at least one wall with your primary home, or is built as an addition designed to function as a separate unit. It can be a cost-effective path when your lot or budget favors building onto the existing structure.
How an attached ADU differs from a detached unit
An attached ADU connects to the main house, so it can share structure, a wall, or utility runs. That can lower some costs compared with a standalone build, but it ties the project more closely to the existing home and its systems. A home addition built to serve as an independent unit, with its own entrance, kitchen, and bathroom, falls into the same category.
Typical uses
- Adding a rental or in-law unit without giving up backyard space.
- Extending an existing home and converting part of it into a separate dwelling.
- Lots where a separate detached structure is not practical.
What the matched builder handles
We connect you with a licensed local builder who serves your jurisdiction. The builder handles design, engineering, permitting, and construction, including how the addition ties into your existing home. We are a matching and marketing service, not a contractor.
What to consider
- How the new unit connects to the existing structure, roofline, and foundation.
- Shared versus separate utilities and metering.
- Size and setback rules for your jurisdiction, which differ from lot to lot.
- Whether your goals are better served by a detached unit or a conversion instead.
Not sure an attached unit fits your property? Work through whether you can build an ADU on your lot first.
Keep researching
Get matched with a Spokane ADU builder
Tell us about your lot and project. We connect you with a licensed local builder who serves your jurisdiction. It is free to you, with no obligation.
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