Bend ADU rules, in plain English
Bend has been one of the more ADU-friendly cities in Oregon. The basics, from the City of Bend's ADU resource hub:
- Size: each ADU must be 800 square feet or less.
- How many: up to two ADUs on a residential lot with a single-unit home, townhome or manufactured home.
- Fees: ADUs pay permit fees and system development charges (SDCs). Since January 2025, the City's SDC deferral program is open to all residential development, so SDCs can be paid at certificate of occupancy instead of up front.
- Wildfire code: Bend adopted the state's R327 wildfire building standards for new homes and new accessory structures, effective for permits submitted on or after May 15, 2026. A new detached ADU counts, so expect ember-resistant vents, noncombustible or ignition-resistant materials and similar details. Our home hardening guide explains what that means.
Setbacks, height, lot coverage, design standards and utility rules depend on your zone and lot. Before you pay for full plans, ask the City's Development Services team or your builder for a feasibility check.
Questions go to Bend Development Services: development@bendoregon.gov or 541-388-5580.
The 800 square foot line matters more than you think
In 2024, KTVZ reported on a Bend homeowner who stopped building after being told his planned unit was too big to count as an ADU, which brought SDCs close to $60,000. The lesson: design to the rules before you fall in love with a floor plan. Ask your designer exactly how the City measures ADU square footage for your design (lofts, covered porches and attached garages are where people get surprised), and get that answer before you submit.
Types of ADUs and what each one costs you in complexity
Bend site conditions that change ADU budgets
- Rock. Many Bend lots have basalt close to the surface. Footings and utility trenches can require breaking or blasting. Ask builders how they price rock and whether they will dig test holes.
- Utility runs. Sewer depth, water meter sizing and electric panel capacity can add thousands. A septic property outside city sewer is a different project entirely.
- Snow and design loads. Roofs must be engineered for local snow loads; this is routine for good builders, but prefab or out-of-area plans need checking.
- Access. A narrow side yard or a backyard behind a fence can mean hand-carrying materials and smaller equipment.
A realistic ADU timeline
- Feasibility (2–4 weeks): zoning, setbacks, utilities, rough budget.
- Design and drawings (1–3 months): faster with pre-designed plans.
- Permit review (varies): ask the City or your builder for current review times.
- Construction (often 5–9 months for a detached unit): foundation, framing, rough-ins, inspections, finishes.
- Final inspections and certificate of occupancy: deferred SDCs come due here.
How to hire an ADU builder in Bend
Ask every builder:
- How many ADUs have you completed in the City of Bend in the last two years? Can I see one?
- Do you handle design and permitting, or do I bring plans?
- How do you price rock excavation and utility trenching?
- Have you built under the new R327 wildfire standards yet?
- How do you estimate SDCs and permit fees, and are they in your number?
- Who is my day-to-day contact, and how often will I hear from them?
- Fixed price or cost-plus? What is in the allowances?