Seattle-area home additions that work with your home's existing footprint and character, from design through construction under one fixed-price contract.
Seattle-area home additions range from targeted bump-outs to full second stories, and the investment scales accordingly. See which scope level below lines up with what you have in mind.
Just a Few Extra Feet.
Sometimes a kitchen remodel or bathroom renovation calls for just a bit more room. A bump-out extends an existing wall by a few feet, giving the project the square footage it needs without fundamentally changing the home's footprint.
Significant Expansion of an Existing Floor.
A standard addition builds new, dedicated space onto an existing floor of your home. It typically involves its own foundation, framing, roofing, and systems, and is designed from the start to feel like it was always part of the house.
Building Up or Down.
Adding a second story or excavating a basement transforms the fundamental structure of your home. These are the most complex additions Neil Kelly builds, involving significant engineering, permitting, and coordination from the ground up.
Neil Kelly's designers have planned additions across Seattle, Bellevue, Redmond, and the greater Puget Sound area, in homes spanning nearly every decade of construction. They know how to tie a bump-out into a Capitol Hill Craftsman's original roofline, how an Eastside mid-century home's structure dictates where a second story can go, and what it takes to add on to an older Seattle house without it looking like an afterthought.
Each designer brings a distinct area of expertise: structural additions, historic and character homes, multigenerational layouts, and a range of aesthetic sensibilities from clean and contemporary to warm and traditional. Getting an addition right is crucial, so having that depth of experience on your project matters.
Here's what Seattle-area homeowners say about working with Neil Kelly.
4.6 out of 5 · 2,200+ verified reviews on GuildQuality
Project was completed within the promised time. The work was outstanding, and the crew was accessible for information.
NK has done a wonderful job with my 1901 house! I would (and have) recommended them to anyone who wants something a bit more creative, thoughtful & fun! My only negative is I have run out of projects for them…
They are very skillful, trustworthy and reliable. They guided us through the process without overwhelming us with decisions. We could leave all the management of the project parts to them and still make decisions that were important to us. They handled all the subcontracting.
Every Neil Kelly home addition moves through six clear phases, with the same Seattle-based team handling design, planning, and construction from start to finish. No separate designers, contractors, and subs left to coordinate on their own.
A Neil Kelly designer will come to your home for free 60-to-90-minute discussion. We'll talk through your goals, your constraints, and what kind of home addition is actually possible. No obligation to move forward, and no need to tidy up first.
Scope confirmation, floor plan options, and design direction. You'll see alternatives, receive answers to your questions, and further shape the direction of your project before we make any detailed drawings.
Every drawing, every specification, and every product is selected and documented. This phase is where your home addition concept becomes a clear plan and pricing gets finalized.
The number we agree on is what you pay. We file permits, order materials, and set the schedule. No surprises when construction starts.
Construction by Neil Kelly's in-house carpenters. You'll get weekly updates from your project manager as they coordinate trades, schedules, and daily details.
Final walkthrough with your project manager. If you notice anything that needs attention, we will address it before you sign off. Five-year warranty coverage starts on completion.
King County's housing stock and permitting processes present specific challenges that may affect your project. Knowing them up front saves time, money, and frustration.
Home additions require permits for structural, electrical, and plumbing work, and in Seattle that means navigating one of the most complex permitting jurisdictions in the Pacific Northwest. The Seattle Department of Construction and Inspections applies rigorous review to any project that changes a home's structure or footprint. Eastside cities like Bellevue, Redmond, and Kirkland each have their own requirements. We work across all of them regularly, file early, and build realistic timelines into every contract.
Roughly one third of Seattle-area homes were built before 1950, and additions to these properties routinely need to tie into conditions that newer homes don't have: balloon framing, lath-and-plaster walls, galvanized plumbing, and foundations that weren't built to support additional square footage. We identify these during the home visit and price them into the scope before work begins.
Seattle's eight designated landmark districts, including Pioneer Square, Harvard-Belmont, and Ballard Avenue, regulate exterior changes to a home, which means an addition in one of these districts is more likely to require design review than a typical interior remodel. We identify whether your property falls within a landmark district during the consultation and build any required review into the project timeline from the start.
Extending electrical service into a new addition often means addressing legacy wiring in the rest of an older Seattle home first, since new circuits typically need to tie into the home's existing electrical system. We coordinate this through trusted, licensed electricians as part of the project scope.
Additions require new foundation work that ties into the existing structure, and in Seattle that means accounting for seismic zone requirements as well as the shifting or sloping ground conditions common under older homes. Our designers and engineers work together early so these requirements are built into the project from the start, not discovered partway through construction.
The Seattle office serves the greater Seattle metro area including Seattle, Bellevue, Kirkland, Redmond, Mercer Island, Shoreline, Edmonds, and surrounding Puget Sound communities.
Cost depends on size, scope, and whether major structural changes are required. A small bump-out typically costs less than a full addition. Neil Kelly provides accurate estimates during the design phase.
Timeline varies by scope — a simple bump-out may take a few months; a full addition with new foundation, plumbing, and electrical can take 6-12 months or more. The design phase adds time before construction begins.
Yes. Second-story additions require structural evaluation of the existing foundation and framing, and involve significant permitting and engineering. Neil Kelly design-build team manages all of this.
Generally yes — labor costs and permit fees tend to run higher in the Seattle market than in Oregon markets. Material costs are comparable. Your designer will provide a market-specific estimate.
A bump-out extends an existing room by a few feet using the existing foundation. A full addition adds notable square footage with its own foundation, framing, roofline, and systems. Bump-outs are less expensive; full additions are more involved.
Adding well-designed square footage typically increases a home's market value, especially for ADUs, primary suite additions, or additional bedrooms. ROI varies by market and project quality.
Neil Kelly serves clients across the Seattle metro. Common areas include Capitol Hill, Queen Anne, Bellevue, Kirkland, Madison Park, Mercer Island, and the Eastside.
Design-build remodeling services are available across all four markets (Portland, Seattle, Eugene, Bend). Handyman Services are available in Portland, Bend and Eugene. Solar is available in Portland only.
Schedule a consultation with our Seattle team and find out what it actually takes to add on to your home, from permitting through final walkthrough.
