The problem
You've been told an ADU is easy. It isn't.
Beaverton's ADU rules changed in 2024, and again quietly in 2025. Most general contractors lean on a designer who's never read the city's checklist. Most ADU specialists can't handle the structural work when your soil report comes back rough. You end up paying twice — once for the build, once for the change orders.
- Permits in your name (you chase the city when something kicks back).
- An ADU specialist who subs out foundation and structural to whoever's cheapest that week.
- Three months of plan revisions because the designer didn't know Beaverton's setback rule.
- A bid that swells 30% mid-build with 'unforeseen' site work.
- No one PM to call. The salesperson disappeared after deposit.
The solution
One license. One architect. One PM. Permit in our name.
We're a full general contractor that also builds ADUs — not an ADU shop that subs out anything that gets hard. CCB #204939, architect on payroll, three PE engineering partners on retainer, six specialized in-house crews, owned excavators.
Detached new-build
Standalone ADU, separate entrance, max rental income, max privacy. Best for lots ≥ 5,000 sqft with rear access.
Attached add-on
Bolted to main house with separate entrance. Often easiest permitting on sloped lots. Works on most Beaverton parcels.
Internal conversion
Basement, attic, or garage conversion. Lowest cost, fastest permit. Best if you already have unfinished space.
Permit in our name
Green O's CCB license, insurance, and bond on the application. We absorb plan-review revisions.
Financing partners
Hearth + Service Finance Co for construction-to-perm and HELOC. We're not a lender — we just don't make you go shopping alone.
Rental income projection
Free on the feasibility call. Verified Beaverton comp data. Tells you if the build pays for itself.
The plan
Three steps. No mystery.
StoryBrand-clear. Most projects move from call to keys in 8–14 months.
Free feasibility call (30 min)
We pull your parcel, zoning, and utility data. You walk away with a plain-English yes/no on whether your lot supports detached, attached, or internal, plus a one-page budget category breakdown.
Design + permit (1–6 months)
Our in-house licensed architect drafts plans. We submit to City of Beaverton in Green O's name. We absorb plan-review revisions. You sign off before we break ground.
Build + move-in (4–8 months)
Our crews self-perform foundation, framing, MEP rough, finish. One PM, one COI, one weekly Friday update. Final inspection scheduled by us. Keys to you.
What clients say
4.3 stars · 51 verified Google reviews.
Every review on our Google Business Profile is public, verified, and unedited. Read all 51 — including the imperfect ones.
“Green O handled our basement ADU conversion start to finish. Architect on staff was the difference — plans cleared review on the first pass.”
“We interviewed four ADU builders. Green O was the only one who pulled our parcel data on the first call. They told us what wouldn't work before we'd written a check.”
“PM responded same day, every day. When the city kicked back our sewer lateral, they had it fixed in 48 hours.”
What it really costs
We don't quote ADU prices online. Here's why.
Every Beaverton lot is different — and a public number is almost always wrong. What we do quote: a transparent breakdown of what drives the cost on yours.
Five things drive ADU cost more than anything else:
- Detached vs internal. Internal conversions (basement, garage) typically run a fraction of a new detached build.
- Site conditions. Slope, soil bearing, utility runs, and whether your sewer lateral can handle a second unit. We assess on the feasibility call.
- Finish level. Builder-grade vs designer finishes can swing the per-square-foot dramatically.
- Permit + SDC fees. Beaverton system development charges are non-negotiable and vary by unit type.
- Design complexity. A simple rectangle costs less than an L-shape with cathedral ceilings. We design to your goals and budget, not the other way around.
On the feasibility call we give you a written budget category breakdown — site work, foundation, framing, MEP, finishes, permits, contingency — so you can talk to your lender intelligently. No pressure, no upsell.
Questions, answered
ADU FAQ — Beaverton 2026.
The questions we hear on every feasibility call, answered plainly.
Does Beaverton allow ADUs on my lot?
Beaverton allows one ADU on most single-family lots, and recent state-level legislation (Oregon SB 1051 + 2024 City updates) has expanded what's possible — including detached, attached, and internal (basement / garage conversion) configurations. Whether yours qualifies depends on lot size, zoning, setbacks, and access. We pull your parcel data on the free feasibility call and tell you exactly what fits.
How long does an ADU take from first call to move-in?
Typical Beaverton ADU runs 8–14 months end-to-end: 1–2 months design + permit prep, 3–4 months permitting and review, 4–8 months build depending on whether it's a detached new-build (longer) or a basement/garage conversion (faster). We pull permits in our name so the timeline doesn't stall on paperwork you have to chase.
What's the difference between attached, detached, and internal ADUs?
Detached = freestanding new structure (best privacy, highest rental income, highest cost). Attached = bolted onto the main house (often easier permitting on sloped lots). Internal = converting existing space like a basement, attic, or garage (lowest cost, faster permits, harder if existing structure is older). We walk every option against your lot and goals on the feasibility call.
Can I rent the ADU out long-term or short-term?
Long-term rental is allowed under Beaverton residential code. Short-term rental (STR / Airbnb) requires a separate City of Beaverton STR permit and has its own rules — you must occupy either the primary or the ADU. We'll flag the implications during design so you don't build something that locks out the use case you wanted.
What does an ADU realistically cost in Beaverton in 2026?
We don't quote dollar figures online because every lot is different — soil, slope, utility runs, finish level, and conversion vs new-build all swing it dramatically. What we will tell you on the feasibility call: a one-page budget breakdown by category (site work, foundation, framing, MEP, finishes, permits) so you can plan financing intelligently.
Can the rental income cover my construction loan?
Often, yes — especially for detached ADUs in walkable Beaverton neighborhoods (Old Town, Five Oaks, Cedar Hills). Current 1-BR ADU rents in Beaverton run a healthy multiple of comparable construction-to-perm payments at typical 2026 rates. We provide a free rental income projection using verified Beaverton comp data on the feasibility call.
Do you offer financing for ADUs?
We work with Hearth and Service Finance Co for construction-to-perm and HELOC products designed for ADU builds. We're not a lender — we just don't make you go shopping alone. Architects, lenders, and PM under one roof.
Who pulls the permit — me or you?
We do. Permit goes in Green O's name. Our license (CCB #204939) is on the application, our insurance is on file, and we handle every inspection callback. If a plan reviewer kicks something back, that's our problem, not yours.
What happens if the city changes the rules mid-project?
Beaverton ADU code has evolved fast — we've built through three rule changes since 2022. Our scope contract includes a regulatory change clause: if the city updates code in a way that affects unbuilt scope, we re-scope in writing before continuing, no surprise charges.
Why pick Green O for an ADU vs a specialty ADU builder?
Specialty ADU shops are great at the build, often weak at structural and site work. We're a full GC — 6 in-house crews, owned excavators, architect on payroll, PE engineering partners — so when your lot needs a retaining wall, an upgraded sewer lateral, or a foundation re-pin, we don't sub it out and add a markup. One PM owns the whole job.
Risk reversal
Three promises in writing.
What every Green O ADU contract spells out — before you sign.
Written scope, no surprise charges
Detailed scope contract before deposit. If we find unforeseen conditions, you get a written change order with line items and a revised total — no verbal 'oh, that'll be extra.'
Manufacturer warranty in your name
CertainTeed roof, James Hardie siding, Andersen windows — every warranty registered to you, not us. If we go out of business tomorrow, your warranty still works.
Two-year workmanship warranty
On top of manufacturer warranties, we warranty our work for two years. Call us, we come back. That's it.
Free inspection — no obligation, written report yours to keep
Probably not the right move if you want the cheapest bid.
If you want this done once — by a CCB-licensed local who'll still answer the phone in year seven — we reply to every web inquiry inside 15 minutes during business hours (Mon–Sat 8 AM–7 PM PT). Storm damage or active leak? Call (971) 226-7751 — same-day callback.
Direct line
(971) 226-7751
Hours
Mon–Sat
8 AM – 7 PM PT
Office
20001 SW Tualatin Valley Hwy
Suite 208
Beaverton, OR 97006
Storm Response
24-hour callback
365 days/year