Cost and planning guide

Questions to Ask an ADU Builder

The point of builder questions is to expose assumptions before they become change orders. Ask about city experience, drawings, corrections, utilities, site work, garage constraints, budget, and who is responsible for what.

Reviewed 2026-05-15

Guide

What homeowners need to know.

Scope questions

What is included, what is excluded, and what assumptions would change the price?

Permit questions

Who prepares drawings, submits plans, responds to city comments, and coordinates inspections?

Site questions

What do you know about utilities, access, foundation, drainage, fire access, and existing structure condition?

Cost table

Use ranges until scope is real.

Item Planning range Why it moves
Early consultation Often free-$1k+ May be sales-oriented unless tied to a real deliverable.
Feasibility review $1k-$5k+ Better when you need property-specific answers.
Construction proposal After scope Only useful when drawings and assumptions are explicit.

Mistakes

Avoid these expensive shortcuts.

  • Asking only 'how much per square foot?'
  • Not asking who owns permit corrections.
  • Skipping utility and site-work exclusions.
  • Accepting verbal scope where the money lives.

FAQ

Fast answers.

What is the most important question to ask an ADU builder?

Ask what assumptions are behind the price and what would cause that price to change.

Sources

Official and provider sources checked.

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