new permit timelines and pre-approved plans

SDCI DADU permit times

Thank you to everyone who joined us at the Seattle Adu Fair last Saturday. It was great to meet so many of you in person.


We've fielded a lot of questions about Seattle Department of Construction and Inspections (SDCI)'s permitting times and how pre-approved plans for DADUs may affect them.  To answer these questions, we have been crunching the numbers. The good news - there's been significant improvement since DADUs were given a high priority this fall, reducing the amount of review and processing time to get a construction permit by 50% from this time last year.

What about pre-approved plans?

The Office of Planning and Community Development (OPCD)'s Pre-Approved Plans for Accessory Dwelling Units fact sheet states that pre-approved plans can receive a building permit in 2-6 weeks (pre-approved or standard plans have already been reviewed for ordinance, structural (O/S) and energy). The city's hope is that by having these reviews completed beforehand, permit review times will go down - which seems logical but unfortunately doesn't align with our experience which indicates the O/S and Energy reviews are not driving overall permit approval times.

To analyze this, we reviewed permit histories from similar DADUs both recently permitted (indicated in gray) and those from this time last year (indicated in yellow) to see what was driving permit timelines.  In the nine projects we examined, the O/S and Energy reviews only increased permitting time twice. And in those instances the delay was minor averaging only 3 days.

Removing the delays caused by O/S and energy reviews, the average review and processing time for a DADU permit is 46 days (excluding from submittal to intake). The review and and processing time including O/S and energy reviews is 49 days. Unfortunately, means that pre-approved plans do not significantly affect the time-frame. A realistic time-frame for pre approved plans being 7-10 weeks, significantly longer than the 2-6 weeks stated by OPCD.

There is good work being done to tighten permit timelines

The OPCD's Pre-Approved Plans for Accessory Dwelling Units fact sheet states that the typical DADU permit takes 4-8 months.  This includes the 4 months required to secure a permit intake date.  To improve this, SDCI recently announced the intake express which promises all intakes will take place within 2-3 weeks. Using the intake express time-frame, and the data on permit processing time shows us that there is no significant difference in review and processing time for pre-approved or custom designs.  A realistic time-frame for review and processing of custom designs being 7-10 weeks - significantly less than the stated 4-8 months.