Look for work that resembles your ADU
A garage conversion and a detached ADU can have similar floor areas but different problems to solve. Look beyond the number of projects in a portfolio. Ask about work with a similar building type, property condition, level of finish and service arrangement.
For an existing garage, ask what the company had to change in the original building. For a detached unit, ask how it handled utility connections and limited access. For a customized design, ask how it coordinated plans and later revisions. You are trying to understand what the team has actually done.
Understand who will help you with what
One proposal may cover drawings, agency coordination and construction. Another may start only after you have approved plans. Ask for those boundaries in writing so you can compare the whole route to a finished ADU.
Find out who will be your day-to-day contact and who will supervise the site. If design is included, ask who prepares it, which rounds of revisions are included and whether engineering or utility applications are separate. A promise to “handle everything” needs a usable description.
A construction Consultant may help if you want independent help reading the scope or contract. That is an optional service with its own fee and role, not a requirement for every simple ADU.
Give bidders the same starting point
The ADU Quote Basis is a short description of the project each price assumes. It does not require the Contractor to disclose every internal construction cost. It does make differences in the services, building, site and finish assumptions visible.
| Topic | Information to share or ask the bidder to identify |
|---|---|
| ADU and design | Detached, attached or conversion; standard or customized design; approximate size; available plans. |
| Existing site | Structures to remove, existing foundation, slope, access and known utility conditions. Mark unknowns as unknown. |
| Utilities and services | Electric and water meter assumptions, gas or all-electric design, connections and any required upgrades. |
| Finish choices | Included products or a defined allowance for items not chosen yet. |
| Owner responsibilities | Appliances, light fixtures, cabinets, flooring, landscaping or other items you intend to buy or arrange. |
| Excluded and undecided work | Design, fees, utility charges, outside work or investigations that are not in the price. |
If a site visit changes an assumption, share the same update with every bidder. Otherwise the new total may reflect better information rather than a different price for the same work.
Compare bids, scope and the differences
Begin with the pricing method: square-foot rate, lump sum or cost-plus. Then compare the work each total covers. Use one place to record exclusions, allowances and unresolved items so a low starting number does not hide a large unknown.
An allowance is an agreed budget for a defined item that will be settled later under the contract. Ask what it covers, what bills you will see and how an overage or credit will be calculated. Keep an allowance separate from money you hold for unexpected costs.
Compare ADU Contractor bids in Los Angeles, then use the full bid-scope guide.
A simple bid clarification format
| Item | Bidder’s response |
|---|---|
| Included scope | Included / excluded / not yet priced; point to the proposal section. |
| Allowance | Amount, covered items, supporting bill and credit or overage terms. |
| Open assumption | What still needs checking, who checks it, and how the result affects price. |
| Owner purchase | Who supplies it, who installs it, and when it is needed. |
Make the written agreement match the decision
Before signing, read the proposal, drawings, exclusions and payment schedule together. Ask for a written correction if one document contradicts another. Keep the agreed versions so a later revision is easy to identify.
For California home improvement contracts, CSLB explains written agreement and change requirements. Whether those provisions apply to your particular ADU agreement needs confirmation; new construction and separate design agreements should not be assumed to use identical rules. CSLB: Contracts and binding agreements
Make time to understand payment requests, changes, delays and ending the agreement. If the terms are unclear or the commitment is substantial, have a qualified attorney review them before you sign. Read the ADU contract guide.
What you’ll be clear about
- What kind of Contractor fits your project, and which experience and services matter.
- How to compare bids, scope and the differences.
- Which items remain allowances, exclusions or unresolved assumptions.
- What to check before signing the contract.
ADU quote basis and bid comparison checklist
Use these prompts when you talk with your project team. Keep technical findings and official approvals with the people qualified to provide them.
Your checkmarks stay on this page until you leave. Download the blank PDF or print your checked copy to keep it.
Questions about this topic
Should I choose the lowest bid?
First establish what it includes. A lower price may be attractive if the services and scope fit, but exclusions and unresolved conditions still need a place in your overall budget.
Read more: How to compare ADU Contractor bids in Los AngelesLink to this answerDo I need a detailed construction cost breakdown?
Not necessarily for a defined lump-sum ADU. You still need enough detail to understand the scope, allowances, exclusions, payment milestones and how changes will be priced.
Read more: What an ADU bid should includeLink to this answerSources and review notes
Official references checked on . Inline links identify the source for specific statements.
Prepared for PrepareToBuild.info as an editorial draft, assisted by AI. Not yet reviewed by a licensed construction or legal professional. Practical examples are illustrative, not actual quotes, legal terms or completed projects. Confirm requirements with the responsible agency and get qualified advice about your property, contract or finances.
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