Substantial alterations are a part of the Seattle Residential Code (SRC) that is applied when a large percentage of the house is being renovated or a large addition is being constructed; SRC Section R107.9. The requirements of substantial alterations are to update the house to the current code for major life safety items of fire, egress, and seismic. Substantial alterations may be required when an attached accessory dwelling unit (AADU) is created as an addition to an existing house. Traditionally, SDCI has given a break from substantial alterations when an AADU is being created in an existing house to support the housing need in Seattle, though this break has not been given when a new addition to a house is for an AADU. Recently, SDCI has revised the policy to allow fire wall construction in compliance with Seattle Building Code 706 to separate a new addition from an existing dwelling unit per SRC 107.5.
The City’s accessory dwelling units (ADU) regulations were recently updated, by Ordinance 125854, and went into effect on August 8, 2019. The updated regulations removed the owner occupancy requirement for ADUs.
The new accessory dwelling unit regulations go into effect on August 8, 2019. This was a multiyear effort to help increase the number and variety of housing options in single-family zones and to remove barriers to developing accessory dwelling units in the city.
Recent legislation (Council Bill 119544) made it easier for property owners to build accessory dwelling units (i.e., backyard cottages) to give more housing options for people living in Seattle. In our digital age, having more people living on one parcel will likely also mean increased internet usage – and an increased need for broadband capacity. A home may already have an internet service connection, but that doesn’t necessarily mean that connection can easily be extended or shared with a new residence on the parcel.