Westwood Express PermittingWESTWOODExpress Permitting
Knowledge hub

Permitting,
demystified.

No jargon, no guesswork. Plain-English guides to how residential permitting actually works in Seattle — written by the team that does it every day.

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Permit basics

Do You Need a Permit in Seattle? A Homeowner's Guide

The complete, plain-English guide to when a residential project needs a permit in Seattle — the four permit paths, what's exempt, and the mistakes that cost months.

Read the guide12 min read
DADU & ADU

How Big Can Your Backyard Cottage (DADU) Be in Seattle?

Size isn't a single number — it's the result of height, setbacks, lot coverage, and floor-area limits. Here's what actually decides your DADU's buildable envelope.

Read7 min
Middle housing

Middle Housing in Seattle: Up to Four Homes on Your Lot

Washington's 2023 middle-housing law lets most Seattle lots hold far more than one home. Here's what it means in plain language — and what's actually permittable now.

Read8 min
DADU & ADU

Turning a Basement or Garage Into a Legal ADU (and Legalizing Unpermitted Units)

Converting existing space is often the lowest-cost way to add a unit — if you clear the life-safety and energy requirements. Plus: how to legalize work already done without a permit.

Read7 min
Timelines

How Long Does a Seattle Permit Take? SDCI Timelines, Explained

Why two similar projects can have wildly different timelines — and the handful of factors that actually move the clock at SDCI.

Read6 min
Cost

What Does Residential Permitting Cost in Seattle?

Permit fees, service fees, and the hidden costs homeowners miss — and why a flat fee with revisions included usually beats hourly.

Read6 min

Still not sure what
your project needs?

Skip the research. Tell us about your lot and we'll map the permit path and timeline for you.

Start Permit ReviewCall (206) 555-0148