SAN DIEGO ADU COST
What belongs in your ADU budget?
Your ADU budget depends on what you want to build and the work your property needs. Use this guide to understand the costs to include, from plans and permits to construction.
THE SHORT ANSWER
Start with the whole project.
Plan for design, permits, site work, construction, and financing, plus a reserve for unexpected costs. Include all of these when comparing your options.
Check my propertyTHE ALL-IN BUDGET
Six parts of the total.
Path, size, layout, and finish level
Design, drafting, and triggered studies
Reviews, permits, and agency charges
Access, drainage, sewer, water, and power
Structure, systems, fixtures, and appliances
Coordination, financing, and contingency
ONE NUMBER
Construction quote
May cover only the work in the builder’s scope.
WHAT IT LEAVES OUT
Additional costs
Plans, fees, site work, utilities, financing, and a reserve, wherever the quote leaves them out.
THE FULL DECISION
Total project budget
Use the full budget when comparing options.
Check what the quote already includes before adding plans, fees, utilities, or other costs.
COMMON QUESTIONS
What homeowners ask next.
Is cost per square foot useful?
It can be a rough comparison after the scope is defined. It is weak when fixed costs, utilities, site conditions, and exclusions differ.
Are permit fees the same for every ADU?
No. City schedules are starting points. The actual project type, size, disciplines, and outside-agency charges determine the final invoice.
Should I include financing in the project budget?
Yes, if borrowing is part of the plan. Keep financing costs separate from design and construction so the decision remains clear.
How large should the contingency be?
That depends on design certainty, site conditions, existing structure, contract scope, and unresolved risks. Name the risks before setting the reserve.
YOUR PROPERTY IS THE NEXT QUESTION
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