You have decided to build an ADU on your Beaverton property. You have probably already asked the question every prospective ADU owner asks first: when can I actually move tenants in? The honest answer is built out of two clocks — the permit clock and the construction clock — and most homeowners only see one of them. This is the week-by-week breakdown of the permit clock the way we actually run it: what happens in weeks 1, 4, 8, 12, where the time really gets lost, and which moves shave entire weeks off the schedule without cutting corners.
The two clocks
An ADU has a permit clock (your application's journey through Beaverton planning, plan review, and corrections) and a construction clock (the build itself). The permit clock typically runs 8 to 14 weeks for a detached ADU. Construction runs 8 to 26 weeks depending on type. This article maps the permit clock. For construction sequencing, see our companion piece on ADU permits, pathway, timeline, and cost.
Weeks 1-2: Discovery and feasibility
The first two weeks are not glamorous and they are the most important. We pull zoning, verify lot dimensions, check setbacks, look up height limits, and confirm the existing sewer and water service capacity. We walk the lot with the owner and identify constraints: tree preservation zones, easements, slope, driveway access for a trenching machine. The questions that derail permits months later get answered here, in the first ten working days, before a designer touches a sheet.
Output of weeks 1-2: a one-page feasibility memo with a yes/no/maybe-with-conditions verdict, the recommended ADU type (internal, attached, or detached), and a rough scope for design weeks.
Weeks 3-5: Design and engineering
Architectural plans, structural calculations, energy code compliance, and the mechanical/plumbing layouts. Because we have a full-time licensed architect on payroll and formal partnerships with structural, civil, and geotechnical PEs, this stage runs in tight parallel rather than sequentially. The most common avoidable delay at this stage is owners changing the floor plan in week 5 — every late change ripples through engineering and adds days.
Output of weeks 3-5: a complete submittal package — architectural set, structural calcs, energy code worksheet (signed by the right credential), site plan with dimensioned setbacks, utility connection plan, and any required land use exhibits.
Week 6: Submittal
We file the building permit application with the City of Beaverton, with any required land use review running in parallel where the type allows. This is the moment that separates contractors who know what they are doing from contractors who do not. A complete first submittal is the single highest-leverage move on the whole project. Sloppy submittals get returned for missing documents before the city even starts reviewing — the clock does not really start until the package is complete.
Weeks 7-9: Plan review (first round)
The city's plan review is structural, residential, mechanical, plumbing, electrical, energy, and (for detached) planning/land use. Each discipline reviews on its own track. Standard review windows have widened over the last several years across Oregon municipalities; the City of Beaverton publishes current targets but the lived experience is roughly three weeks for a typical detached ADU on first round. The faster your reviewers can move through your package, the faster you get to corrections. Clear, well-organized sheets with clean dimensions move faster than dense ones — even if the content is identical.
Free ADU feasibility walk
We will walk your lot, pull the zoning, check the setbacks, and tell you whether your property supports an ADU at all — before you spend a dollar on design.
Weeks 10-11: Corrections and resubmittal
The city returns its first-round comments. Some are clarifications ("dimension this", "label this", "show the rated assembly"), some are real corrections that touch engineering. We triage the corrections list within 48 hours: which need a redrawn sheet, which need a revised calc, which can be answered with a memo. We resubmit within a week on most projects. Owners who hire general contractors who do not have in-house design routinely spend three to six weeks at this step because the corrections bounce through external designers and engineers.
Weeks 12-14: Issuance
Final reviewer sign-off, fee payment, permit issuance. This is the moment the construction clock starts. We pre-mobilize during week 13: order materials, schedule the framer, line up the subcontractor sequence, file utility company applications for new services if the design requires them. The day the permit issues, the dumpster is on site and the crew has a start date.
Where the weeks really get lost
In our experience, avoidable delays cluster in five places:
- Incomplete first submittals. Missing structural calcs, unsigned energy worksheets, ambiguous site plan setbacks. Add 4-8 weeks.
- Owner-initiated design changes after submittal. Each change can mean a resubmittal cycle. Add 2-6 weeks.
- Slow correction turnaround. Contractors without in-house design routinely take three weeks to answer a one-week correction list.
- Utility coordination surprises. Discovering at framing that the existing meter needs upgrading.
- Land use appeals. Rare for ADUs but possible. Always check neighbor relationships before assuming none.
The three fastest-path moves
- Hire a GC with in-house design. Every coordination handoff between a designer, engineer, and contractor is a week of dead time. We put the architect, engineer, and project manager in the same Slack channel.
- Lock the floor plan before submittal. Owners who change layouts after submittal pay the largest schedule penalty. Settle the design in weeks 3-5 and live with it.
- Submit a complete package the first time. Every missing exhibit is a week. We have a 47-item submittal checklist we run before every Beaverton ADU package leaves our office.
Realistic construction-clock numbers after permit issuance
| ADU type | Permit clock | Construction clock | Total to CO |
|---|---|---|---|
| Internal conversion | 6-10 weeks | 8-14 weeks | 14-24 weeks |
| Attached addition | 8-12 weeks | 14-22 weeks | 22-34 weeks |
| Detached standalone | 10-14 weeks | 16-26 weeks | 26-40 weeks |
What we hand the homeowner at week 1
Every Green O ADU project starts with a one-page weekly tracker that lists every milestone, the responsible party, and the trigger date. Owners see exactly where the project is at any moment. We update it Monday morning. This is the same transparency our commercial GC clients get — see our piece on how to hire a commercial GC in Portland for the broader filter.
External references and credentials
For city-side authority on ADU rules and current submittal expectations, the City of Beaverton Building Division publishes current handouts and fee schedules. The Oregon Building Codes Division publishes the residential and energy specialty codes that govern the technical content of any ADU submittal. We hold CCB #204939, and our designs cross every Oregon and Beaverton code requirement before they reach a city reviewer's desk.
Related Green O resources
- Additions and ADUs services — full menu and process.
- Pathway, fees, and cost overview — companion article.
- Case study: Mosaic Arts Loft — additions and structural sequencing.
- Beaverton service area — neighborhoods and response time.
- Book a free feasibility walk — Mon-Sat 8 AM to 7 PM.