Seattle ADUs: What is an ADU and Why Should I Want One? 

Accessory dwelling units (ADUs) are becoming more popular in Seattle as people look for ways to increase the amount of housing available in an increasingly expensive market, but what is an ADU? ADUs can take many different forms, but all offer a way to add extra living space and income. If you’re on the fence about whether an ADU is right for you, this article will provide more information as to what they are, how they work and some of the pros and cons of owning one. 

Magnolia Basement ADU Remodel

What is an ADU? 

The question, “What is an ADU?” has been on the minds of many Seattle homeowners lately, as the city experiences a movement toward building more accessory dwelling units (ADUs). Accessory dwelling units (ADUs) — also known as mother-in-law suites, guest houses or backyard cottages — are units that typically include their own bedroom, bathroom, kitchen and living space and are built on the same property as the main house. They differ from detached accessory dwelling units (DADUs). While DADUs are the same concept, they are detached from the main house and built in a different area of the property. For the purposes of this article, we will be discussing both structures under the term ADU. 

Popular in the early 20th century, ADUs saw a decline in construction post-WWII when families began moving toward the newly developing suburbs. They only recently came into favor as a beneficial option for homeowners.  

Northwest Seattle Detached Accessory Dwelling Unit (DADU) Project

Are ADUs a good investment? 

There are several benefits of ADUs, which means they can be a good investment for homeowners. First, they typically increase the value of your home (see below). Additionally, if you rent out your ADU, you can generate extra income to help offset your mortgage or other living expenses. Finally, when thinking about downsizing, an ADU can provide a place for you (or a family member) to live while still maintaining your privacy and independence. 

Does an ADU increase my property value in Seattle? 

ADUs are a popular amenity in Seattle, so in general, they can increase the value of your property by adding extra living space to your home. A 2021 Porch study noted that a home in Seattle with an ADU is priced 18% higher (on average) than one without one. However, it’s important to note that the value of your property will also depend on factors like the location and condition of your home. 

What are the drawbacks of owning a rental ADU? 

There are also some potential drawbacks to owning an ADU. For starters, if you plan to rent out your ADU, there will be costs that you’ll need to account for. You’ll have cleaning expenses between short-term guests as well as the expense for basic supplies (paper towels, toilet paper, soap, etc.). You’ll also have to carry additional insurance, conduct regular maintenance on the property and have the added expense of utilities. Additionally, there are local rules about ADUs and vacation rentals that you’ll need to adhere to, so be sure to stay on top of them. Finally, the ADU has the potential to be an intrusion on your privacy, as your renting guest will need access to certain parts of your property.  

Some of the ADU projects we’ve completed

What are some creative designs for ADUs that I can use as inspiration? 

If you are considering building an ADU, the first place to look for ADU designs is your potential builders’ website. We’ve successfully completed many ADU projects in our service area. You can also view the ADUinverse’s gallery of pre-approved DADU designs (of which Harjo is included), for more ideas.  

How can I find out if I can build an ADU on my property? 

Contact us to discuss more. We’ll visit your property and provide you with a feasibility study and preliminary design.