Go Far®Home additions · Seattle
Home additions in Seattle.
Seattle houses run out of room long before their owners want to leave the neighborhood — and an addition is how you stay. Go Far Construction builds additions across Seattle: second-story additions, primary suites, family rooms, and bump-outs, engineered properly and finished so the new space reads as original to the house, from a family-owned, licensed Washington general contractor.
On Seattle’s tight lots, the first question is up or out. Second-story additions are the signature project here — building up can nearly double a house without giving up yard, at the cost of more engineering and a new roof structure; our second-story addition guide covers what that takes. Where the lot allows, ground-floor additions — a primary suite, a family room off the kitchen, a bump-out that fixes a cramped bath — are simpler builds, all covered on our home additions service page.
On budget: most additions in this market price out between roughly $300 and $550 per square foot, with complex or high-end projects going beyond that — an addition builds new house from the foundation up, which is why it prices differently than a remodel. Our home addition cost guide breaks down the ranges by addition type, and our addition vs. moving guide runs the numbers against buying the next house.
Every Seattle addition is permitted through the Seattle Department of Construction and Inspections (SDCI), and most involve structural review; we prepare and track the application, carry fees in an itemized written estimate, and meet every inspector on site, as on all our Seattle projects. If the space you need is a separate unit rather than more house, our Seattle ADU & DADU page covers that route.
What we build in Seattle
Seattle home addition questions
How much does a home addition cost in Seattle?
In this market, most additions price out between roughly $300 and $550 per square foot, with complex or high-end projects going beyond that. A bump-out is the entry point, a single-room addition typically lands in the low-to-mid six figures, and primary suites cost more per square foot because of the plumbing and tile involved. Every project gets an itemized written estimate.
Should I build up or out in Seattle?
It depends on your lot. Seattle lots are often too tight for a ground-floor addition, which is why second-story additions are so common here — building up can nearly double a house without giving up any yard, at the cost of more engineering and a new roof structure. We walk both options with real numbers before design begins.
Do I need a permit for a home addition in Seattle?
Yes — every addition needs a permit through the Seattle Department of Construction and Inspections (SDCI), and most involve structural review. We prepare and track the application, include fees in your itemized written estimate, and meet every inspector on site.
Is an addition better than moving in Seattle?
Often, yes. Between selling costs, moving costs, and the price of the next house, adding the space you’re missing frequently wins the math — especially if you like your location. Our addition-vs-moving guide runs the Puget Sound numbers side by side.
Plan your project
Planning a Seattle addition? Useful next reads: home addition costs · addition timelines · addition vs. moving · second-story additions · Seattle ADUs & DADUs · Bellevue additions · Lynnwood additions · our Seattle page · all of King County