Monroe Street rowhouses.  Image by Mr.TinDC licensed under Creative Commons.

Building an income-producing basement, apartment, or other unit for someone to live in on your lot in DC is easier to do now, thanks to new zoning laws the city just passed. 

DC wants to promote building these units, because they can help address the local housing shortage–and make homeowners money in the process.

What are accessory apartments anyway?

These income-producing units are called Accessory Dwelling Units or ADUs, but GGWash usually refers to them as "accessory apartments" because that sounds less like a reference to a Hobbit house. They are defined in DC as, “a dwelling unit that is secondary to the principal single household dwelling unit...but which has kitchen and bath facilities separate from the principal dwelling and may have a separate entrance.”

As GGWash has highlighted previously, this zoning law change allows DC homeowners in much of the city to build additional units on their property to rent out or use. They no longer need to  request to deviate from current zoning requirements in order to build. (However, Georgetown homeowners need to seek a special exception from the Board of Zoning Adjustment due to the historical nature of the neighborhood.)

Accessory apartments increase the density of people living in residential areas and could create more affordable housing in highly desirable neighborhoods. Accessory apartments also provide environmental benefits to the community by allowing renters to live in the city and walk to amenities, thereby driving less.

Kay Pierson, Director of Community Reinvestment for the United Planning Organization, says these units can allow senior citizens to stay in their own homes as they grew older. (She’s written for us previously about various ways to make money with your house.) These owners who have equity in their homes could use that equity to pay to build an accessory apartment, either to rent out or to live in themselves–allowing them to rent out the larger home if they no longer need as much space.

While DC has not yet started tracking accessory apartments, more and more projects seem to be coming down the pike.

The Coalition for Smarter Growth recently held a conference to promote the new DC’s new ADU regulations, and I attended to see how to go about actually constructing an accessory apartment. Here are the practical how-to’s of getting one built on your property in DC.

How to build your own accessory apartment:

  1. Talk to an architect and have plans drawn up.
     
  2. Head to the Department of Consumer and Regulatory Affairs (DCRA) for a pre-permitting consult which costs between $400 and $600. The DCRA will tell you if there’s anything wrong with your plans that must be fixed before applying for a building permit. There is currently a four-week waiting period for these appointments, so plan accordingly.
     
  3. After you make the recommended changes, you apply for your building permits. Approval is currently taking somewhere between two and six months.
     
  4. While you are waiting, work on financing. There are two options: cash or home equity line of credit. Depending on how much your unit costs and the amount of money you are able to make when renting the unit, you can calculate how long it will take to recoup your investment in the accessory apartment. (Online calculators make this easier to do.)

    Owners should expect to spend between $100 and $200 a square foot on the units, which is comparable to the cost of building an average sized new home in DC. Although the units are smaller, this does not necessarily reduce the square-foot cost.  
     
  5. Build!
     
  6. Have the unit inspected.
     
  7. If you are renting out the unit, you must then apply for a Single Family Business license from DCRA.

Once you receive your single family business license, you're free to begin renting your unit! Hopefully this guide has demystified the accessory dwelling process a bit.

This article has been updated to reflect that while you do need to have your unit inspected, you don't need to receive a certificate of occupancy.