ADU, Accessory Dwelling Units
What is an ADU?
An Accessory Dwelling Unit (ADU) is one or more rooms with a private bath and kitchen facilities comprising an independent, self-contained dwelling unit within or attached to a single-family dwelling or in a detached building on the same lot as the primary dwelling unit.
An ADU is legal only with an established building permit.
For a complete listing of zoning code requirements for accessory dwelling units, please refer to VMC 20.810 Accessory Dwelling Units.
This project may be eligible for tax relief for up to three years.
Note: You must file your application with the Assessor’s Office before construction is completed.
- Clark County Assessor – Homeowner’s Remodel Exemption
- Improvements to single-family dwellings, including both attached and detached ADUs
What applications are needed when I submit for an ADU?
New Detached Structure
Addition or Remodel of Existing Structure
Where can I build an ADU?
ADUs are allowed as limited uses on all lots.
How many ADUs can I build on a single lot?
Up to two ADU’s may be created in conjunction with each parcel.
Are owners required to live on the property?
No, the property owner is not required to live on the property where an ADU is located.
Is a covenant required?
A covenant is no longer required due to recent changes in state law.
What are the size limitations for an ADU?
An ADU shall not exceed 1,000 square feet.
The gross floor area of an ADU shall not be less than the requirements of the Washington State Building Code.
Is on-site parking required for an ADU?
No additional on-site parking is required in conjunction with the establishment of an ADU. However, the conversion or construction of an ADU cannot eliminate the required parking for the main dwelling. The main dwelling is required a minimum of one parking space, which can be in a garage or an approved 9’x17’ pad attached to a driveway on the property.
Does an ADU need to be visually subordinate to the main dwelling?
An ADU no longer needs to visually subordinate to the main dwelling, nor architecturally compatible with the principal dwelling.
What are the required setback and lot coverage requirements for an ADU?
An ADU addition to an existing house or the construction of a new ADU shall not exceed the allowable lot coverage or encroach into required setbacks as prescribed in the underlying zone for the primary structure.
Can I convert my existing accessory structure into an ADU?
Yes, an existing garage structure or other outbuilding may be converted to an ADU.
Which energy forms are required?
Energy Forms are required for new dwellings, when adding new dwelling area, and when converting unheated space to heated space. When building a new home and an ADU at the same time, separate energy compliance forms are required for each dwelling.
How do I know if I have adequate electrical service?
Contact Clark Public Utilities at 360-992-8558 to request verification of transformer capacity.
Will existing overhead electrical lines need to be moved?
If you are enlarging your home (an addition) or building a new detached ADU, contact Clark Public Utilities at 360-992-8558 to request required clearances of overhead lines.
Should I hire a professional to design my ADU?
It is not required, however due to the complexity of these projects, we recommend that you hire a professional to assist in the design process.
Additional questions?
For questions on setbacks or development standards, please email cddplanning@cityofvancouver.us
For building code questions, please email planreview@cityofvancouver.us