Experience seamless home additions with JDI Construction in Milwaukie. We promise quality craftsmanship, timely delivery and customized solutions to uplift your living experience.
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Camas, WACamas, WA — California
DavidDavid — Vancouver, WA
Portland's #1 Remodeler
500+ completed projects
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4.9/5 rating
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4.9/5 rating
A well-built addition disappears — you can't tell where the old house ends and the new one begins. JDI Construction is a family-owned, Vancouver-based design-build remodeler, and that disappearing act is what we're really building toward: an addition expands the home you already have, unlike an ADU, which stands as a separate unit. In close-in Milwaukie, where pre-war bungalows and mid-century homes sit on tighter lots than the metro's newer suburbs, making new work vanish into old takes both careful design and a builder who understands how those houses were put together.
Our designers and trades work as one team, so the addition you approve is drawn to tie into the house that's actually there — we don't hand a set of plans to a separate crew and hope the new roof and foundation line up. On a Milwaukie lot with little room to spare, that coordination is what keeps the design honest about what will actually fit.
Whatever the size of the project, an addition comes down to a handful of parts done well — and these are the ones that decide whether it holds up and reads as one home:
The shape of an addition is set by decisions that come before design. The first is direction — out or up. On Milwaukie's tighter lots there may be little room to build out, which pushes more projects upward; going up avoids using yard but depends on the existing foundation and framing being able to carry the added load, and on an older bungalow that's a real question rather than a formality. The second is capacity: whether the current foundation, electrical panel, and heating and cooling system can serve the new square footage or need upgrading — older homes often need it. The third is what the parcel allows, since setback lines, lot-coverage limits, and height rules vary by jurisdiction and bite hardest on small lots. We work through all of it up front so the plan fits the house, the lot, and the budget.
Most Milwaukie additions come from wanting more room in a close-in neighborhood worth staying in — a primary suite, another bedroom, a larger family room, or a real home office — rather than trading it for a bigger house farther out. Because an addition is attached and shares the roof, systems, and foundation with the main house, it keeps everything under one roofline instead of standing apart the way a separate ADU would, which matters on a tight lot where a second building may not even fit.
The matching challenge here leans older. On the pre-war bungalows and mid-century homes that fill many Milwaukie blocks, the hard part is matching siding profiles, trim, and rooflines that have weathered for decades. Newer homes in the area are easier to match but more likely to carry HOA or lot-coverage limits to design around. Either way, the seams are what tell the story — the foundation where new footings meet old, the roofline and its pitch, the exterior skin, and the interior transitions in floor and ceiling height — and we treat those as the difference between an addition that looks original and one that looks added on.
Cost is driven first by type: a bump-out that leans on the existing structure costs far less than a second-story addition that requires reinforcing the foundation and framing beneath it — and second stories are common here where lots are tight. After that it's size, how much structural work the tie-in demands, how hard the existing materials are to match on an older home, and whether the systems need extending or upgrading. Because our design and our trades are both in-house, we price those realities honestly up front and give you an itemized estimate once the addition is drawn, so the number reflects your house and your lot rather than a generic per-square-foot figure.
An addition runs in months rather than weeks, because it moves through design and engineering, permitting, foundation and framing, the tie-in to the existing structure, and finally finishes. A second-story or structural addition takes longer than a simple bump-out, and an older bungalow can hold surprises that only appear once walls are opened. We give you a realistic schedule before demolition, handle the engineering and permits the work requires, and sequence the build to keep the existing home weather-tight and livable while the new space goes up.
An addition is where design-build earns its keep, because the design, the structural engineering, and the construction all have to agree for new and old to meet cleanly. As a single accountable team, we handle the plans, the load paths, the tie-in, and the finishes under one roof, so nothing falls through the gap between an architect and a separate builder — a gap that's especially costly on the older homes common in Milwaukie. We manage the permitting, keep you updated through our client portal, and stand behind the work with a five-year workmanship warranty. Milwaukie is a short drive from our Vancouver base, close enough for us to stay on-site and responsive throughout a project this involved.
Book a free in-home consultation. We'll look at your home and lot, talk through where and how to add on, and follow up with a clear plan and a 3D design layout. Ask about our current $1,500 offer.
JDI Construction — "Built by family. Trusted by neighbors." Design-build remodeling and home additions based in downtown Vancouver, WA, serving Milwaukie and the greater Portland–Vancouver metro since 2007.
Serviced ZIP Codes: 97222, 97267, 97269
Why JDI
Clear, upfront pricing with zero hidden costs.
Local craftsmanship serving Vancouver and Portland since 2007.
Designed for beauty, built for lasting durability.
Confidence and protection every step of the way.
We treat your home like it's our own.
We begin by assessing whether local codes and neighborhood covenants allow for your desired addition. Our team will help you understand zoning laws and other constraints that may impact the feasibility of your project. We will conduct a detailed site assessment to ensure that the intended area can support additional structure both physically and legally.
We recommend you consider how the addition will affect your current home layout, structural integrity, and exterior aesthetics. Think about the purpose of the addition—whether it’s for extra living space, improving home value, or other reasons—and let us help you align this with practical considerations such as budget, potential ROI, and the blend with existing architecture.
Absolutely! We handle all aspects of permit acquisition for your new addition. This includes preparing and submitting all necessary drawings and documents to the local building authorities. We stay updated with Milwaukie’s specific regulations to ensure a smooth approval process.
The duration of a home addition project can vary significantly based on size, complexity, weather conditions, and permit approval times. Generally, a project can take anywhere from a few weeks to several months. We will provide you with a detailed timeline once we’ve evaluated the specifics of your project and completed the planning phase.
In Milwaukie, sunrooms, extended living rooms, and additional bedrooms are highly sought after. We ensure that each addition complements your home by matching or coordinating with existing materials, design style, and colors. Our design team works closely with you to create a seamless transition from old to new, enhancing both function and form.
We approach unforeseen challenges with a proactive and solution-oriented mindset. Whether it’s unanticipated structural issues or delays due to weather, we communicate transparently with you about the issues and the implications. Our experienced team is equipped to make adjustments necessary to overcome challenges while still adhering to high standards of quality and safety.
We prioritize sustainability and efficiency in all our projects. For home additions, we use energy-efficient windows, superior insulation materials, and HVAC systems that conserve energy. Our construction methods also include practices to minimize waste and incorporate renewable materials where feasible. We can discuss specific technologies that might be suitable for boosting the energy efficiency of your new addition.
We’ll help you understand all financial facets of your home addition, including detailed cost estimates, potential return on investment, and financing options available. It’s also wise to consider the ongoing maintenance costs, increased property tax implications, and utility expenses associated with larger living spaces. We recommend setting aside a contingency fund for any unforeseen costs during the construction phase.
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Discover the potential of your Milwaukie home with top-notch additions. Reach out to us now for more details!



