Home Additions That Fit Your Life

Home Additions in Beaverton.

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 in Beaverton since 1996 — backed by a fixed price and a completion date we actually hold to.

A space that grows with you

ADUs & Home Additions Fit For 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

Property Improvements 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 from an ADU or Home Addition.

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

From ground-up custom homes to full commercial buildouts, kitchen renovations to backyard ADUs — we handle the full range of residential and commercial construction across Beaverton. One team, every service, to the same standard.

Design-Build

Architecture and construction, one team.

Commercial Projects

Offices, retail, and tenant improvements.

Custom Homes

New homes built around your vision, from the ground up.

Residential Remodels

Room-by-room updates or full-home overhauls.

ADUs & Additions

New space added to your property.

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

A Home Renovation in NE Portland

De Marco Builders completed a full interior and exterior renovation, transforming a 1936 NE Portland home into an updated Portland […]

More Room to Grow: A Restaurant Expansion in Hillsboro

De Marco Builders delivered this commercial build in Hillsboro, Oregon — a new banquet room, a redesigned entrance, and a […]

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 […]

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Service Area

Greater Portland Metro Area, OR