Home Additions in the Seattle–Tacoma area
When the house you love no longer fits the life you live, a whole-home addition changes the equation — new wings, expanded living areas, in-law suites, and reimagined floor plans that give your family room to grow without leaving the neighborhood that feels like home.
The overview
Our approach to home addition
The homes around Milton and the greater Seattle-Tacoma area were largely built for another era's families: modest footprints, closed kitchens, no home office, one shared bath. Meanwhile moving up means today's prices, today's interest rates, and leaving schools and neighbors behind. A substantial home addition resolves that math — often delivering the space of a larger home for less total cost than trading up.
What distinguishes a whole-home addition from a simple bump-out is integration. Adding a wing or expanding across the back of the house changes circulation, light, and how every adjacent room works. Our in-house design team plans the addition and the existing home together, rendering the combined result in 3D so you can walk the new floor plan before committing.
Five generations of structural building experience, license HOMERDB750MH, Pierce and King County permitting fluency, and financing assistance make us the team local families trust with their largest home investment short of buying new.
A note from Donovan
Your home addition, treated like it's our own home.
I'm Donovan. My family has been building across the South Sound for five generations, and every home addition project we take on gets the same promise: an honest budget range, a design you can walk through in photorealistic 3D before we build it, and a crew that treats your house the way we'd treat our own.
You won't be handed off to a call center or a stranger with a clipboard. You'll work with the same family that's earned its reputation one neighbor at a time — and we don't consider the job done until it feels like home.
— Donovan
Owner & Lead Designer · Licensed WA #HOMERDB750MH
Free design consultation
Tell us about your home addition project and Donovan's team will reply within one business day — no obligation, just honest advice.
Why choose us
What sets our home addition apart
Whole-Home Design Thinking
We design the addition and reconfigure adjacent existing spaces together, so the expanded home flows as one plan instead of a house with a box attached.
In-Law & Multi-Generational Suites
Private bedrooms, baths, and living areas — with separate entries where appropriate — that let parents or adult children live close with dignity.
Family Room & Kitchen Expansions
Great-room additions that open the back of the house to light and yard, transforming the daily heart of family life.
Invisible Structural Integration
Foundations, framing, and rooflines engineered and matched so the addition reads as original construction from the street and from inside.
Energy-Smart New Construction
The new space is built to modern envelope standards — often becoming the most comfortable, efficient part of the entire home.
Full Permitting & Engineering
Zoning review, setbacks, structural engineering, and inspections managed completely across local jurisdictions.
How it works
Our design-build process
Feasibility & Priorities
We assess your lot's zoning envelope and your home's structure, then align what is possible with what your family needs most.
Integrated Design
Our designers develop the addition and touched existing spaces as one plan, presented in 3D renderings for your refinement.
Engineering, Pricing & Permits
Structural drawings, a fixed itemized proposal, and permit submittals proceed together to keep the schedule tight.
Construction
Foundation through weathertight shell to finished interiors, sequenced so your existing home stays sealed and livable until the final tie-in.
Tie-In & Completion
The new and old spaces are joined, finishes are blended, and we complete inspections, walkthrough, and warranty handover.
When the tools come down and the crew heads home, what's left is yours — a house that finally feels like home.
Donovan& the crew
Start your home addition projectFAQs
Home Addition questions
Is adding on cheaper than buying a bigger house?
Frequently, yes — once you account for selling costs, moving, higher purchase prices, and losing a low mortgage rate, a well-planned addition often delivers the needed space for less while letting you stay put. We can help you run the comparison with real numbers.
What does a home addition cost?
Substantial additions in our region generally run $400 to $650+ per square foot depending on complexity — bathrooms and kitchens raise the average, simple living space lowers it. Your design-based proposal fixes the number before construction, and financing assistance is available.
How big an addition does my lot allow?
Setbacks, lot coverage limits, and height rules vary by city and zone across Pierce and King County. We research your parcel's specific envelope during feasibility, before design money is spent.
Will you match my home's exterior?
Meticulously. Siding profiles, roof pitch, eave details, windows, and trim are matched or deliberately complemented so the addition is indistinguishable from the original structure.
Can the addition include a full second kitchen for my parents?
Depending on local zoning, in-law suites can often include kitchenettes or full kitchens; some configurations may qualify as accessory dwelling units. We design to the rules of your jurisdiction and advise you on the options.
How long does a whole-home addition take?
Expect two to four months of design, engineering, and permitting, then four to eight months of construction depending on scale. Because work happens largely outside your existing walls, daily life continues with modest disruption until the brief tie-in phase.