What belongs in an ADU budget?

Compare like with like.

A detached building, an attached addition and a conversion begin with different conditions. A conversion already has a structure, but its foundations, openings, services and intended use still need assessment. Existing walls do not establish that a conversion will be the least expensive route.

Describe the intended household and use before asking for a number. Access, privacy, storage and the relationship to the main home can change the brief even when two layouts have similar floor areas.

Look beyond the living space.

Ask the design and construction team to identify proposed utility connections and the areas affected by work. A budget should make clear who investigates capacity, obtains provider requirements and prices any necessary work. Do not assume a nearby connection is suitable simply because it exists.

Review access for deliveries, equipment and waste removal. Also discuss what needs to be protected or restored around the work. Keep these questions visible before comparing a building-only price with a more complete proposal.

Use a budget with clear boundaries.

List professional services, approvals and jurisdiction fees separately from the construction scope. Then identify owner purchases and any allowances for unselected finishes. The purpose is to prevent a cost from being counted twice or omitted, not to prescribe who must provide each service.

Fees depend on the proposal and applicable rules. Use current city and state resources, and request an itemized estimate from the relevant authority. Do not rely on an old article’s blanket fee exemption or rental-income forecast.

• Design, survey and investigation responsibilities
• Permit and other agency fees
• Structure, envelope and interior work
• Utilities and affected outdoor areas
• Selections, allowances and owner-supplied items

Bring the unanswered questions.

For each estimate, ask what information was available, what is excluded and which assumptions may change as the design develops. Ask how those changes will be discussed and approved. This is more useful than a headline price without a scope.

You can start a conversation before every decision is made. Share the city, the type of ADU you are considering and any drawings you have. Sami & Sons offers complimentary estimates.