Bump-out
A bump-out extends a wall to enlarge an existing room. It may use a foundation, posts, or engineered cantilever framing. The small footprint does not eliminate structural, setback, drainage, or roof work.
Best Home Addition Contractors in Kirkland and Redmond (2026)
An addition asks an existing house to carry new loads, accept a new roofline, connect utilities, and pass review as one structure. Compare contractors by the part of that problem they are prepared to own.
Which contractor fits which addition?
- Alta Group Remodeling is positioned for additions connected to a larger interior redesign, such as a new primary suite beside a reworked kitchen or whole-home plan.
- Armada Design & Build publishes an integrated design-build process with zoning, structural engineering, permits, and construction under one contract.
- Sound Renovation publishes additions ranging from bump-outs and rooms to garage conversions and second stories, with Eastside service dating to 1991.
- Eastside Construction gives second-story additions a dedicated Kirkland service page and reports operating since 1985.
- Signature Build emphasizes Kirkland design, permitting, additions, ADUs, garage conversions, and construction coordination.
Addition in view
Plan the connection before pricing the finishes.
The foundation, load path, roof tie-in, drainage, and permit path determine whether the new space works as part of the original house.
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Published 15 September 2026. Original editorial illustrations generated for Hamed Helped; they do not depict a named contractor, client, or project.
Scope first
How do four common addition types change the risk?
Single-story room
A room addition adds foundation, exterior walls, roof, insulation, utilities, and finishes. Soil, water movement, lot coverage, and the roof connection deserve attention before interior selections.
Second story
The design team must evaluate the existing foundation, walls, lateral system, stairs, utilities, and temporary weather protection. Structural engineering should shape the proposal before construction pricing is treated as final.
Garage conversion or over-garage addition
Confirm slab and footing capacity, ceiling height, insulation, moisture control, fire separation, egress, parking rules, and utility routes. Existing garage space is not automatically ready for residential use.
Budget exposure
Which three conditions can change an addition proposal?
Foundation and site
Slope, drainage, soil, trees, setbacks, utilities, and critical areas affect what can be built and how the new foundation is designed.
Roof and envelope
Pitch, valleys, flashing, siding transitions, gutters, and temporary weather protection determine how the new work keeps water out.
Existing systems
Electrical service, plumbing routes, HVAC capacity, framing, insulation, and code-triggered work can appear after design review or selective demolition.
Selections and access
Custom windows, doors, cabinetry, tile, site access, staging, and occupied-home protection can alter both procurement and the build sequence.
Quick comparison
How do the five Eastside addition contractors compare?
We reviewed each company's public site for addition-specific services, Eastside coverage, a stated process, and details a homeowner can verify before requesting a proposal. The order reflects project fit, not a measured workmanship score.
| Company | Published base or office | Published history | Best fit from stated services |
|---|---|---|---|
| Alta Group Remodeling | Everett | Not stated | Addition plus interior redesign |
| Armada Design & Build | Bellevue | Established 2011 | Integrated design-build and complex scope |
| Sound Renovation | Redmond | Serving the Eastside since 1991 | Bump-outs, rooms, conversions, second stories |
| Eastside Construction | Snohomish | Since 1985 | Second-story additions |
| Signature Build | Everett and Tacoma offices | Not stated | Kirkland permits, additions, ADUs, conversions |
Company profiles
What does each home addition contractor publish?
Alta Group Remodeling
Best fit: an addition that also changes a primary suite, kitchen, bathroom, or whole-home layout.
Alta Group Remodeling publishes home additions, ADUs, whole-home remodeling, kitchens, bathrooms, and custom construction among its services. Its stated five-stage process moves from discovery and planning through build, refinement, and final use. The company says it can provide 3D renderings and serves Kirkland, Redmond, Bellevue, Seattle, Everett, and surrounding King and Snohomish County communities.
Confirm: the current Washington registration, structural and architectural partners, permit responsibilities, design deliverables, and how pricing changes when the addition opens existing walls.
Armada Design & Build
Best fit: a project that benefits from one contract covering feasibility, design, engineering, permits, and construction.
Armada describes itself as a Bellevue design-build firm established in 2011. Its additions material states that the team reviews zoning, setbacks, lot coverage, critical-area or shoreline overlays, structural engineering, permit documents, and construction. The company lists both Kirkland and Redmond in its service area.
Confirm: which site constraints apply to the parcel, who stamps each plan, whether published review ranges apply to your jurisdiction, and what work remains an allowance.
Sound Renovation
Best fit: a contained room addition, bump-out, garage conversion, or second-story project where long Eastside operating history matters.
Sound Renovation says it has served Seattle and the Greater Eastside since 1991. Its Redmond and Kirkland addition pages name house additions, room additions, bump-outs, conservatories, garage conversions, and second-story work. Its site also says it works with designers, engineers, and architects rather than presenting all design services as in-house.
Confirm: the exact legal registration, design team, engineering scope, lead-safe procedures when relevant, and a recent project similar in structure and jurisdiction.
Eastside Construction
Best fit: homeowners specifically interviewing contractors for a second-story addition.
Eastside Construction publishes a dedicated second-story addition page for Kirkland and reports providing remodeling services since 1985. The company lists a Snohomish address and describes consultation, estimating, scheduling, and construction as its process.
Confirm: current registration and insurance, structural engineering arrangements, who prepares permit documents, a written schedule, and references for completed second-story work.
Signature Build
Best fit: a Kirkland addition, ADU, or garage conversion where the homeowner wants one team coordinating design, permit work, and construction.
Signature Build's Kirkland page lists custom homes, ADUs and DADUs, garage conversions, home additions, whole-home remodeling, and commercial work. It says its process includes design planning, permit drawings and approvals, and construction. The same page publishes offices in Everett and Tacoma rather than a Kirkland office.
Confirm: the exact business entity and registration, who is truly in-house, which office and project manager will run the job, and examples of recent Kirkland approvals.
Before signing
Which questions should every addition contractor answer?
- Who owns structural engineering, and when does it happen?
Ask who evaluates the existing foundation and load path, who stamps the calculations, and whether that work occurs before a construction price is treated as firm.
- What is your recent permit experience in this city?
Request project examples from the same jurisdiction and similar scope. City review time depends on completeness, site conditions, workload, corrections, and project complexity.
- How are existing-condition surprises priced?
Separate allowances, exclusions, unit prices, contingencies, and change-order rules for framing, electrical service, plumbing, rot, soil, and drainage.
- How will the new roof and walls connect to the old envelope?
Request drawings and written specifications for flashing, weather barriers, roofing, siding, gutters, and temporary protection during the opening.
- Can the house remain occupied?
Record dust control, access, egress, utility shutdowns, temporary partitions, work hours, weather protection, and the point at which temporary relocation may be required.
Permit reality
How should homeowners interpret permit timelines?
The City of Kirkland says review time depends on plan completeness, site conditions, project extent, contact availability, staff workload, and corrections. Some single-family alterations and additions may qualify for an approximately two-week Fast Track first review when they meet the city's criteria, but complex structural work and sensitive site conditions can disqualify a project.
A contractor's quoted permit range is an estimate, not a city commitment. Ask for separate assumptions covering design, engineering, initial review, correction cycles, outside approvals, and material ordering. Redmond follows its own process, so a recent Kirkland schedule should not be copied into a Redmond proposal.
FAQ
What else should Eastside homeowners know?
How long does a home addition take in Kirkland or Redmond?
There is no reliable single duration. Ask bidders to separate design, engineering, city review, correction cycles, procurement, construction, and contingency time.
Is a second-story addition cheaper than moving?
It can be, but foundation reinforcement, wall and lateral work, stairs, utilities, temporary housing, and financing can change the comparison. Start with structural feasibility.
Do I need an architect for an addition?
You need permit-ready design and often structural engineering. Those services may be independent or coordinated by a design-build contractor. Confirm who prepares, stamps, submits, and revises each document.
Can I live in the house during construction?
Sometimes. The tie-in, utility interruptions, dust, egress, weather protection, and access to kitchens and bathrooms determine whether occupancy remains practical and safe.
Why can additions cost more per square foot than a new build?
An addition requires selective demolition, protection, matching work, constrained access, and careful connections between new and existing foundations, framing, utilities, and finishes.
How do I verify a Washington contractor?
Use the Washington Department of Labor and Industries Verify tool. Check the exact legal name, registration, bond, insurance, citations, and license history shown on the proposal.
Decision summary
Choose the team whose evidence matches the structural problem.
Evidence trail
Sources checked for this guide
- 01Alta Group Remodeling website
Services, five-stage process, 3D design support, contact details, and Eastside service areas.
- 02Armada Design & Build website
Company history, Bellevue base, design-build process, additions scope, permit coordination, and service area.
- 03Sound Renovation website
Operating history, Redmond and Kirkland addition types, professional network, and Eastside coverage.
- 04Eastside Construction website
Second-story addition service, published history, process summary, and Snohomish contact address.
- 05Signature Build Kirkland service page
Additions, ADUs, conversions, design, permit coordination, process, and published office locations.
- 06City of Kirkland Permit Review Times
Review factors, Fast Track eligibility, approximately two-week target, and disqualifying site or structural conditions.
- 07Washington Department of Labor and Industries
Official contractor-registration, bond, insurance, citation, and license-history verification guidance.