Seattle Is Permitting More ADUs Than Single Family Homes

According to a recent article in the Seattle Times, the growth in popularity of ADUs has seen the more ADUs permitted than single family houses. This is a welcome change in that it shows that changes to local regulations meant to encourage ADUs are working, but also that demand ADUs and multi-unit properties is outpacing the antiquated idea of single family houses in our cities.

We are definitely a fan of densifying our cities and ADUs are an important part of that. Density is beneficial for everyone as it leads to more amenities, new neighbors, more customers for local small businesses, and a larger tax base to fund public infrastructure like public transit, parks, and schools.

One of the things that drives what we do is providing more housing opportunities and more affordable homes. As this article points out, ADUs can help achieve these goals whether they are for rental or turned into a for-sale home by condoizing the property.

It is encouraging to see so many new homes being permitted, although this is still just a small drop in the bucket for the number of homes we need to be building to keep up with demand and growth projections. We would love to see ADU regulations be standardized state-wide or even nationally, rather than city by city. Having a patchwork of different rules and restrictions makes ADUs harder to design and build and often limits some types of ADUs, like modular or pre-designed ADUs.

We believe it would benefit everyone to make ADUs more accessible by taking down barriers to this housing type. It would make housing more affordable overall, it would make ADUs more attainable for more homeowners, it would allow for more multi-generational living or co-housing options, and will help meet our housing needs by working within the context of our many single family housing neighborhoods.

Another interesting aspect of this data is the balance between detached ADUs (DADU) - or backyard cottages - and attached ADUs - often called junior adus - which are often renovations to interior spaces like basements or attics. Detached ADUs are definitely leading the way but it was pretty close

It is also interesting to read that ADUs are becoming an amenity that developers are including in new homes. Rather than taking a property and building a single family house, developers see the interest in ADUs and are making projects that already have detached ADUs or attached adus included. And in places where it is allowed, sometimes both - meaning 3 units are being built instead of just one. This is really great to see.

Still, ADUs are a very small percentage of the overall housing production, with the most homes coming from new multi-family housing developments. Out of the approximately 11,000 homes built in the Seattle area, a little under 1,000 came from ADUs. Backyard Cottages, basement apartments, garage conversions, and other types of ADUs are still growing in popularity and will continue to be an important part of our future housing supply. Especially in neighborhoods that aren’t zoned for larger scale development, ADUs can easily become the easiest and most affordable way to add new homes.

Overall, this is great to see in the Seattle area and aligned with what we are seeing in many cities across the country. As more state legislatures adopt state-wide ADU regulations we are optimistic that ADUs will become an even larger piece of the housing pie.