Hudson Remodeling News

Considering an ADU? Here’s what to know.

Posted 30 September 2020 by Team Hudson

Accessory dwelling units have been common in the United States for more than 100 years. Though they fell out of favor during the rapid expansion of the suburbs in the late 1900s, sustainable planning efforts have brought them back into style.

They are a popular item in Whatcom County right now, with homeowners in Bellingham, Ferndale, Lynden and Blaine using them to keep elderly family members close, to make a little extra money through rent, or to have a place for the kids to stay when they’re home from college.

What is an ADU?

An accessory dwelling unit, or ADU, is a structure, basement, attic or other dwelling unit on your property in which someone can live independent of the main living quarters. ADUs have their own spaces for cooking, sanitation, eating, sleeping and living.

You might also have heard an ADU referred to as a mother-in-law suite or guest house.

Among the biggest reasons that cities and counties support ADUs is that they help increase neighborhood infill, reducing sprawl. They aren’t without their detractors, however, and regulations abound to ensure that ADUs don’t harm the character or functionality of the surrounding neighborhood.

So, if you’re interested in turning space in your home or yard into an ADU, be sure to check local rules before starting any planning or design. Some places to get started in Whatcom County are the regulations for Bellingham, Lynden, Ferndale and Whatcom County.

What are the rules regarding ADUs?

A few points to consider when planning an ADU:

  • In most places, at least one dwelling unit on a property that contains an ADU must be owner-occupied.
  • ADUs are limited in size. Typically, detached ADUs cannot be bigger than 800 square feet or half of the main residence, whichever is smaller, though the rules do differ depending on location. In Bellingham, for example, ADUs can be up to 66% of the main house. Also, ADUs that are attached to the main structure can sometimes be larger. In Lynden, for example, attached ADUs can go up to 1,000 square feet and have two bedrooms.
  • There may be additional restrictions on ADUs depending on the zoning in the place you live.
  • ADUs often are required to mimic the design of the main structure. In Bellingham, for example, an ADU must have similar roof pitch, siding and windows. In Ferndale, the width of the ADU may be adjusted to ensure the roof pitch matches the main house.
  • ADUs generally require their own on-site parking, often with one space per bedroom.

If you’re looking to convert an unused basement, attic or shed into accessory living space into an ADU in Whatcom County, feel free to give us a call to go over your options.

And remember that regulations regarding ADUs do change, so be sure to research your local rules before getting started.