Mistakes Homeowners Make When Hiring an ADU Contractor

Most costly ADU mistakes happen before construction even starts — during the contractor selection process itself.

Most of the ADU horror stories homeowners hear about did not start on the construction site — they started during contractor selection, before a single permit was pulled. Here are the mistakes that come up most often.

Hiring based on the lowest bid alone

A bid dramatically lower than others usually means something is excluded — permit fees, utility connections, finish-level materials — that gets reintroduced later as a change order. Compare scope of work line by line, not just the bottom-line number, before deciding.

Not confirming ADU-specific experience

A licensed general contractor is not automatically an experienced ADU builder. ADU projects involve permit paths, setback rules, and utility connection challenges that differ from a standard remodel. Our contractor question checklist covers exactly what to confirm here.

Skipping the license and insurance check

It takes a few minutes to verify a contractor's license status directly, and it is one of the simplest ways to avoid a serious problem later. Every contractor in our network is required to hold an active, appropriate license, but for any contractor you are evaluating outside our network, verify this yourself before signing anything.

Not getting the full scope in writing

Verbal promises about what is included do not hold up when a dispute happens. A detailed written scope of work, tied to your specific site conditions, protects both you and the contractor.

Underestimating the permit timeline

Construction time is often only part of the total project timeline — permit review adds real weeks or months depending on your jurisdiction. Ask about this explicitly rather than assuming your project timeline starts the day you sign a contract. See our permit process guide for the general steps involved.

Not comparing multiple contractors

Getting at least two or three bids from licensed, experienced ADU contractors is one of the most effective ways to catch pricing gaps and scope differences before you commit. Request a match and we can help start that comparison.

Assuming every ADU contractor is interchangeable

Not every contractor who accepts ADU work has built more than one or two. Experience specifically with ADUs — not general remodeling or additions — is what tends to prevent the permit surprises and utility-connection issues that cause the most common project delays. This is worth confirming directly rather than assuming a general contractor's overall reputation automatically covers ADU-specific expertise.