Definition of Accessory Dwelling Units (ADU). “Accessory dwelling unit” means a free standing detached structure or an attached part of a structure that is subordinate and incidental to the main or primary dwelling unit, and having complete living facilities exclusively for one single housekeeping unit, including permanent provisions for living, sleeping, cooking and sanitation. An attached accessory dwelling unit is an accessory dwelling unit that has one or more walls in common with, or attached to, the primary dwelling unit. A detached accessory dwelling unit is a free-standing accessory dwelling unit that is not attached or physically connected to the primary dwelling unit.
A resolution to adopt a policy which sets water and sewer connection fees association with properties with accessory dwelling units located within the service area of Woodinville Water District has been approved at the August 16, 2022 board meeting.
ADU’s attached to a single-family home can use the water meter and side sewer that was permitted for the single family home.
All detached ADU’s shall have its own meter and side sewer connection. A ¾ inch meter shall be the appropriate size for a detached ADU if fire sprinklers are not required. If fire sprinklers are required, the property owner shall install a backflow device (STD 21) behind the District meter.
All water and sewer system development charges shall apply for any new connections and/or modifications to the existing side sewer for an added attached ADU to an existing single-family home.
A Water and Sewer (if applicable) Availability Certificate shall be issued for all new ADU’s proposed per jurisdiction building permit applications.