Late last year, there was an article published in the Seattle-based online news forum Crosscut that provided a good history of how ADUs came into the zoning of may cities across the country, including Seattle. It also examines the role of individual cities in determining land use "regulations, conditions, procedures, and limitations" for ADUs as specified by Washington's Growth Management Act of 1994:
"The City Council will be more subject to court scrutiny if it ventures over the line into politically-driven, arbitrary limits to the cottage permit pipeline (such as the currently proposed 50 DADUs per year). The same would be true if Seattle emulates some other cities by enacting hoop-jumping ordinance provisions that — permitted in theory but impossible to build in practice."
Even though the 50 DADUs a year limit did not pass, this is still a great article, as it raises the point that regulations that can unnecessarily limit the success of ADUs are in the control of local municipalities, and we should be careful to watch out for when they appear.
Accessory Dwelling Units (ADUs) are an affordable type of infill housing. They are small, include a bedroom, kitchen and bathroom, and can be either attached or detached from the main house on the property.