ADU Construction Costs Portland: Budgeting for Your Project

Planning an ADU in Portland requires understanding construction costs before committing to design.
Expenses include permits, labor, materials, and possible site upgrades.
Starting with an accurate cost estimate helps avoid surprises and ensures your project stays on budget.

Key Cost Factors for ADUs in Portland

• Permit fees and city development charges
• Labor costs for framing, plumbing, electrical, and finishing
• Materials for foundation, walls, roofing, and finishes
• Site preparation or grading if needed
• Structural upgrades for garage conversions or second-story ADUs

Detached vs Attached ADU Costs

Detached ADUs generally have higher costs due to separate foundations and utilities,
while attached ADUs can leverage existing infrastructure but may require structural modifications.
Understanding your lot and design constraints helps determine the most cost-effective approach.

How the ADU Feasibility Wizard Helps Estimate Costs

Our interactive

ADU Feasibility Wizard

evaluates your lot in Portland and surrounding areas, helping you identify zoning allowances, setbacks, and development potential.

For a $250 upgrade, the Wizard allows you to download preliminary ADU plans
or upload your own designs to confirm feasibility, which provides a more accurate construction cost estimate before design begins.

Start Planning Your ADU Budget Today

If you’re considering building an ADU in Portland,
use the
ADU Feasibility Wizard
to evaluate your lot, understand zoning and design constraints, and create a realistic budget.
Planning costs upfront ensures a smoother design and permitting process, helping you avoid delays and extra expenses.