ADUs & Home Additions · Beaverton, OR
More Space Same Address.
Looking for an ADU builder in Beaverton you can actually count on? Whether you need room for aging parents, a rental unit, or simply more square footage than your current floor plan allows, De Marco Builders has been planning and building both across the Portland metro since 1996 — backed by a fixed price and a completion date we actually hold to.
Room to grow
Space That Grows With You.
Families change, and homes don't always keep up. A growing household, an aging parent moving in, or a need for rental income can outpace what your current layout can offer. An ADU or addition gives you that extra space without leaving the neighborhood or the home you've already invested in.
For Beaverton households, that project only works if it's planned around how you'll actually use the new space, not just where it fits on the lot. Our team handles design, permitting, and construction as one continuous process, so the finished space matches what you needed it for in the first place — whether that's a private suite, a home office, or a fully independent unit.
THE Built To Belong
Not Just Done, Done Right.
The ideal ADU or addition isn't just a new structure attached to your home — it's one that feels like it was always part of it. That means utilities that tie in seamlessly, a roofline that looks intentional rather than tacked on, and a layout that functions independently when it needs to and connects naturally when it doesn't.
Getting there takes more than good intentions — it takes a team that understands how new construction interacts with an existing home, and how to navigate the permitting and code requirements that come with building in a place like Beaverton. De Marco Builders has managed that process across more than 1,400 projects in the Portland metro, which is exactly why homeowners trust us to get an ADU or addition right the first time.
THE PROCESS
What to Expect.
The process starts with understanding what the new space needs to do — rental unit, in-law suite, extra bedrooms, or a home office — since that shapes everything from layout to permitting requirements. From there, our team takes the project through design, engineering, and Beaverton's permitting process, keeping you updated at each stage instead of going quiet until construction starts.
Once permits are approved, construction moves forward on the schedule we committed to at the start. You'll have one point of contact for the entire project, consistent progress updates, and a completion date that holds — supported by a 100% on-time track record.
WHY DEMARCO
Why Beaverton Clients Choose Us.
Beaverton's longest-serving custom builder
In business since 1996, we know Beaverton's neighborhoods, soils, permits, and inspectors better than anyone.
Fixed price, fixed schedule
What we quote is what you pay. The date we give you is the date we hit. No surprise change orders, no budget creep, no exceptions — not once in 30 years of Portland construction.
One team from start to finish
Design, permits, construction — same crew, same point of contact, from the first site walk to the day we hand you the keys. No gaps in accountability, no finger-pointing when something needs to be fixed.
Award-winning craftsmanship
Recognized by Portland Monthly and the NW Natural Street of Dreams.
Family-owned since day one
Same owners, same values, nearly three decades running. You work with the people whose name is on the door.
Serving all of Portland Metro
From Beaverton and Cedar Hills, to Lake Oswego, Tigard, and every Portland neighborhood in between.
Our Services
Everything We Build in Beaverton
FAQ
Common Questions.
Can't find the answer you're looking for? Reach out and we'll get back to you within one business day.
Do you offer free estimates?
Yes
How long does a typical project take?
It depends on the size, scope, design complexity and permit process.
Typical project timelines include:
- ADUs: 45–60 days
- Home Additions: 45–90 days
- Remodels: 30–90 days
- Custom Homes: 90–160 days
- Commercial Projects: 90–160 days
How do you price a project?
Every proposal from De Marco Builders provides complete cost transparency. Our estimates clearly show the construction costs, company overhead, profit, and total project cost so clients fully understand where every dollar is allocated.
Do you require a deposit?
No. Never. We do not require an upfront deposit. The first payment is due only after a portion of the contracted work has been completed.
What happens if costs change during the project?
We guarantee the contract price through project completion unless the homeowner requests additional work beyond the original scope or unforeseen structural conditions are discovered that were not visible during the initial evaluation.
Can you work within a specific budget?
Absolutely. De Marco Builders is a budget-driven builder. We work within the client’s established budget throughout the design, engineering, permitting, and construction phases. We utilize value-engineering principles to maximize quality while maintaining budget goals.
Are you licensed, bonded, and insured?
Yes. De Marco Builders is fully licensed, bonded, and insured. We maintain all required certifications and operate in full compliance with state regulations.
How do you handle unexpected issues that come up mid-project?
Unexpected issues are rare because of our extensive experience and thorough planning process. If an unforeseen issue does arise, it is addressed immediately, typically within 24 hours. We resolve issues in a code-compliant manner while protecting the project schedule.
How often will I receive updates?
Communication is one of our highest priorities. Once a client signs a contract, we maintain frequent communication throughout design, engineering, permitting, and construction. Clients receive regular progress updates, photos, and end-of-day reports so they remain informed from start to finish.
Our Projects
Recent Work
Design-Build Custom Home in Portland
See how De Marco Builders transformed a 900 sq ft 1946 bungalow into a 2,400 sq ft custom home in just 120 days. Portland’s design-build general contractor.
Whole Home Remodel in NE Portland
Studs-out renovation: new electrical, plumbing, HVAC, two primary suites, relocated kitchen, and white oak finishes — completed in 120 days. Portland remodel contractor.
Portland Backyard Cottage ADU Built in 89 Days
One of Portland’s most efficient ADU builds: an 800 sq ft craftsman backyard cottage, fully permitted and completed in just 89 days.
Ready to Build Something
You'll Love?
Get a free consultation with our team — no commitment, just a conversation about what's possible.
Get in Touch