Updated: Dec 18, 2020
In 2019, the City of Tacoma adopted a new set of regulations that made it much easier to add Accessory Dwelling Units (ADUs) to existing properties. Although the city previously allowed units to be added to single dwelling lots, zoning codes were so restrictive that only 62 ADU projects were actually permitted in the previous five years.
Now, local regulations make the process much more accessible to the average homeowner. Now that zoning codes are less restrictive, ADUs have become a popular way to add affordable housing to the local market. For homeowners, this can increase property value and create a unique passive income stream.
What is an ADU/DADU?
An ADU (Accessory Dwelling Unit) is a separate living area within a house. This could be an attic or basement apartment, for instance. These will typically have a kitchen unit and a separate entry from the main house.
A DADU (Detached Accessory Dwelling Unit) is completely detached from the main house. This includes standalone units like separate in-law apartments and backyard cottages, or even a heated building that’s used as an office or art studio.
The Unique Benefits of Building ADUs/DADUs
In Tacoma, developing affordable housing has been a challenge in recent years. Both space and rising costs have limited available housing in the area. ADUs and DADUs offer a unique solution to these obstacles:
· ADUs and DADUs offer better housing choices to a growing market of fixed-income retirees, college students, young adults looking for their first home, adults with disabilities or special needs, and extended family members who need their own space.
· These units add affordable housing near job opportunities and existing infrastructure to reduce commute times and increase access to local services and cultural centers.
· ADUs/DADUs can be more environmentally friendly living spaces. They offer a smaller footprint and can be designed to significantly reduce energy needs (which provides cost savings as well).
· As housing costs rise, ADUs/DADUs allow residents to remain in neighborhoods and communities that they’ve long called home.
· Accessory units reduce urban sprawl by increasing housing unit density within existing residential zones.
· With an ADU or DADU, homeowners can generate passive income. This allows more homeowners to remain in their current homes despite rising costs, while creating more financial stability and generating economic growth.
· DADUs in particular combine the privacy of a single-family home with a budget-friendly price, since they offer the benefit of no shared walls and a lower-density living space compared to many urban housing options.
· These units provide an opportunity to easily increase property value without restricting housing options for local residents.
Tacoma Building Regulations for ADUs/DADUs
While Tacoma now welcomes more ADUs and DADUs, they still have specific regulations and zoning codes that must be followed by architects and builders.
Make sure you work with a Tacoma builder that understands how to design the in-law suite or rental unit you need while still following city guidelines.
Key changes to previous regulations in Tacoma:
1. The lot size requirement has been removed.
2. The restriction on unrelated residents in ADUs has been removed.
3. The city added an amnesty program that gives residents who built ADUs in the past without the required permit the opportunity to apply for one through 2020.
4. Detached units (DADUs) like backyard cottages are now legal to build.
Other important notes on Tacoma codes for building ADUs and DADUs:
· ADUs and DADUs are now allowed in all residential zones, including converting a garage into an ADU, building an apartment over a garage, or adding a separate backyard cottage.
· Setback requirements are waived when converting existing structures into accessory units.
· Units must be located behind the front wall of the main house.
· DADUs do require a permanent foundation – which means tiny houses on wheels or shipping container units are not permitted.
· The owner occupancy requirement is waived (unless the unit will be used as a short-term rental).
· Accessory units no longer have to completely match the main house in exterior design. They simply need to complement the main home and be of equal or greater value.
· Only one ADU or DADU is allowed per lot.
· ADUs or DADUs can also function as an office space or a home-based business space.
· Maximum size for DADUs is 1,100 square feet or 85% of the size of the main home (whichever is less).
The Best Tacoma Architect for Your ADU/DADU Project
The key to reaping the benefits of a backyard cottage or rental apartment - and avoiding potential pitfalls - is to find the right architect for the job.
ATMO Architecture specializes as an ADU/DADU builder in Tacoma, which means we are well-versed on local regulations and zoning codes.
We understand that regulations can easily become overwhelming. We take care of all the specifics and make sure the project flows smoothly, so you don’t have to stress over it.
Our priority is to create a space that lives up to your imagination – while also meeting the practical needs of design. When you’re ready to start your ADU project, give us a shout and we’ll work together to make your vision come to life.
Contact ATMO today to get started!