An addition isn't a remodel — it's new construction joined to a house that's already standing. Serden Group handles the entire chain in-house: feasibility, engineered plans, permits, foundation, framing, roof tie-in, mechanicals and finishes. One licensed design-build team, one project manager, 1,500+ projects across Clark County and the Portland metro.
Outgrowing your house shouldn't mean leaving the lot, the schools, and the neighborhood you chose. A well-planned addition buys you the primary suite, the second full bathroom, or the ground-floor bedroom you actually need — without agent commissions, a double move, or a reset property tax basis. And because additions touch structure, zoning and every mechanical system at once, they reward one accountable team over a string of separate bids.
Bump-outs. Primary suites. Second stories. ADUs and garage conversions. Structural work, permits, framing, roofing, mechanicals and finish carpentry — sequenced by one project manager from feasibility through final inspection.
Kitchen and family room expansions, sunrooms, home offices, and ground-floor bedrooms — added on a new foundation line.
A true owner’s suite: bedroom, walk-in closet, and spa bath with the plumbing and HVAC properly extended.
Build up when the lot won’t allow out — shear walls, foundation upgrades, new stair, and a full roof rebuild.
In-law suites, garage and basement conversions, and detached ADUs permitted as separate dwelling units.
An addition touches zoning, structure, weatherproofing and every mechanical system at once. Here's the full scope Serden Group coordinates — our own crew on the build, plus licensed, vetted trade partners for engineering and specialty work.
Setback, lot coverage, height and easement review against your zone — before you spend a dollar on design.
Stamped drawings for footings, beams, headers, shear walls and load paths — required on nearly every addition.
Excavation, footings and stem walls, floor system, wall framing and roof structure tied into the existing house.
Matched pitch and overhang, properly flashed valleys, and siding and trim profiles that read as original.
Egress-compliant windows, house wrap, flashing and air sealing built for Pacific Northwest rain, insulated to WA and OR energy code.
Duct or mini-split extension, panel capacity review, new circuits, and plumbing rough-ins for new baths and kitchens.
Wall texture matched to your existing rooms, continuous flooring runs, matched baseboard and casing, doors and built-ins.
Application prep, plan-review corrections, and every inspection managed through final sign-off.
Before you pay for design, we measure your lot against your zone's setbacks, lot coverage and height limits, and check whether your foundation and roof can carry what you want to build. You get an honest yes, a build-up-instead recommendation, or a no — plus a realistic budget range.
Floor plans, elevations and stamped structural drawings, then submittal and plan-review management with Clark County, Vancouver, Camas or Portland Permitting & Development. Every selection and every line of the schedule is approved before material is ordered.
Footings, framing, roof tie-in, mechanicals, then finishes — with your kitchen and bathrooms kept in service and the work zone sealed and dust-controlled. One project manager, one number to call, and a punch-list walkthrough before final inspection.
With Serden Group, you get expert guidance and a stress-free home remodel — from design to final walkthrough.
Great experience working with this company. They were professional, responsive, and the quality of their work was solid. They even took the time to treat me to lunch and go over the project details, which I appreciated. Would recommend.
The SERDEN Group did a complete remodel of our two upstairs bathrooms. Every step of the way Dennis, and his team, were communicative, kind, timely, and productive. They worked diligently, caring about the impact of having workers in your home. Everyone was friendly and attended to our creative ideas for the bathrooms. In the end we have two amazing new bathrooms. Our family is grateful for SERDEN and are wonderfully reminded daily of their excellent work. Thank you!
I recently hired Serden Group for a full kitchen and bathroom remodel, and I couldn't be happier with the results! From start to finish, the team was professional, reliable, and detail-oriented. The quality of their work is outstanding — everything from the tile installation to the cabinetry and finishes looks beautiful and well-crafted. They completed the project on time and within budget, which is rare to find these days. I highly recommend Serden Group to anyone looking for top-quality remodeling work. They truly exceeded my expectations!
I had a very pleasant experience with SERDEN GROUP company. They remodeled my bathroom, and I am completely satisfied with the result. Fast and high-quality work. Denis answered all of my questions, suggested great solutions for the renovation, and delivered everything he promised. I 100% recommend them.
Had the pleasure to work with this team on a project for one of their clients. They followed through with every request from start to finish and we can proudly say that, they really put their best foot forward with all their work. Our team would love to continue to work together for future jobs!
Finished, mid-range attached additions in this metro generally run $200–$400 per square foot. The ranges below are planning numbers for a permitted, fully finished space — not a quote. Your actual price comes off engineered plans after we see your lot and your foundation.
Second stories and any structural reinforcement of the existing house. New kitchens and bathrooms. Sloped or rock-heavy lots. Moving a service panel or upsizing it. Sewer and stormwater work. Historic or design-overlay review in Portland.
Building out on a flat, open lot. Keeping the addition on one plumbing wall. A simple gable that ties into the existing roofline. Converting space that is already under roof, like a garage or basement. Reusing your existing HVAC capacity where it can carry the load.
Structural engineering, permit and plan-review fees, and system development charges tied to added square footage. Stormwater management when a project disturbs enough impervious area. Landscaping and fence repair where equipment had to reach the work.
These three get quoted against each other constantly, and they solve different problems. Here's the honest comparison — including when an addition is the wrong answer.
New square footage joined to your house, sharing its kitchen, entry and utilities.
Best when you need
A separate legal dwelling with its own kitchen, bath and entrance — attached, above a garage, or detached.
Best when you need
Different permit path and utility work. See our Clark County ADU permit guide.
Reworking the space you already have — layout changes, finishes and systems, same footprint.
Best when you need
Often the smarter call on a tight lot. See full home remodeling.
If your lot has no room inside its setbacks, your zone caps lot coverage below what you need, or reworking the existing layout would get you 80% of the result for half the cost, we will tell you that at the feasibility stage — before you have paid for design.
Serden Group builds additions on both sides of the Columbia — bump-outs on Clark County's newer subdivisions, primary suites on Camas hillside lots, and second stories on Portland's older bungalows. Setbacks, lot coverage, stormwater and design review differ in every one of these jurisdictions, and we have permitted work through all of them.
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