An accessory dwelling unit (ADU) is an attached or detached residential unit that provides complete independent living facilities with accommodations for a kitchen, living, sleeping, eating, and bathroom on the same parcel as the primary residence. Accessory dwelling units are not accessory structures and are regulated under Danville Municipal Code Section 32-76.


  • A maximum of one accessory dwelling unit per parcel. The unit cannot be sold separately. The design of the ADU must be compatible with the primary residence.
  • Occupancy: Owner occupancy is required for primary residence or accessory dwelling unit.
  • Size and Bedroom Requirements: The unit size is measured from the outside footprint of the foundation
    • Parcels under 40,000 square feet, ADU’s maximum size is 1,000 square feet, Maximum of 2 bedrooms
    • Parcels 40,000 square feet and larger, ADU’s maximum size is 2,000 square feet, Maximum of 3 bedrooms
  • Setback and Height Requirements:
    • Primary residence setbacks, 2.5 stories or 35 feet maximum height, whichever is less
    • Reduced setbacks: Primary and secondary front setbacks met, then 10’ side and rear setbacks, 15 foot maximum height, Adhere to window placement standards.
  • Parking: An off-street parking space is not required.
  • Garage: If a garage is provided for a detached unit, the garage is limited to a size necessary to accommodate a maximum of 2 standard size parking spaces (440 sq. ft.).
  • Window Placement: Detached accessory units with a setback of ten (10) feet of less on a side or rear property line shall be designed so that any window facing that property line shall be located no less than 6 (six) feet above the finished floor to minimize direct views to adjacent neighboring properties to preserve privacy. This six (6) foot window placement shall also apply to any detached two-story accessory dwelling unit that does not meet the required minimum side or rear yard setback requirements for the primary residence.
  • Utilities: Utilities for detached units are required to be installed underground.
  • Heritage Trees: Units located within a dripline of a protected heritage tree must adhere to the Tree Preservation ordinance.
  • more…...