PROPOSED POLICY CHANGES
following is the list of proposed policy changes, when implemented,
should encourage the construction of more ADUs and DADUs throughout the
city of Seattle.
1. Allow an ADU and DADU on the same lot
policy stipulates that a single-family lot can have an ADU or a DADU,
but not both. New legislation would allow single-family lots to have an
ADU and a DADU.
2. Remove off-street parking requirements
regulations require one additional off-street parking space for either
an ADU or DADU unless the lot is located in an urban village. New
legislation eliminates the off-street parking requirement.
3. Modify the owner occupancy requirement
regulations require that the property owner occupy either the main
house or the ADU/DADU. New legislation would terminate the requirement
12 months after the final inspection for the building permit.
Unfortunately this is only a partial step in the right direction. The
owner occupancy requirement is a significant hurdle for construction
financing, as the bank cannot rent out the ADU/DADU in the event of a
default. This modification may not have much of an impact on
4. Reduce the minimum lot size for DADUs
Current regulations stipulate that only lots 4,000 square feet and larger can have DADU’s. New
would reduce the minimum lot size to 3,200 SF. However, all other
development standards that regulate the location and scale of DADU’s,
such as minimum separation between structures and the maximum lot
coverage limit, would remain in effect.
5. Modify the maximum height limit for DADUs
regulations determine the maximum height of a DADU based on the width
of the lot, with overall height limits set too low to allow conventional
roof geometry. New legislation would simplify this standard and
slightly increases the maximum height limit up to 2 feet depending on
the lot width.
6. Modify the rear yard coverage limit for DADUs
regulations limit coverage of a required rear yard to no more than 40
percent. New legislation would allow an additional 20 percent coverage
only for one-story DADUs to provide flexibility for property owners who
may wish to design a DADU without stairs for mobility or universal
7. Modify maximum gross square footage limits
ADUs are limited to 1,000 square feet and DADUs to 800 square feet. New
legislation would maintain a 1,000 square feet limit for ADUs and
increase the DADU limit to the same 1,000 square feet. This legislation
also removes garage and storage space from counting towards the maximum
gross square footage for ADUs and DADUs.
8. Add flexibility for entry door locations to DADUs
regulations prohibit entrances to DADUs on the facades facing the
nearest side or rear lot lines unless that lot line abuts a public
right-of-way. New legislation would allow an entrance on any facade
provided that the entrance is no closer than 10 feet to side or rear lot
line, unless that lot line abuts a public right-of-way.
9. Allow certain roof features that add interior space
regulations allow these features for principal units in single-family
zones but are not allowed for DADUs. New legislation would allow
certain roof features that accommodate windows and add interior space,
such as dormers, clerestories, and skylights
More on accessory dwelling units in tomorrow's blog! Stay tuned!
Today's blog courtesy of David Taber, Neiman Taber Architects