Build the schedule around your actual design, permit office, utility applications and construction scope. Ask each company to state its assumptions and show which tasks must finish before the next stage starts.
This page is a planning framework, not a completion guarantee.
ADU Property Checks and Project Planning
Confirm the permit office, current use and buildings. Record the owner’s goal, likely ADU type, access and easements. Add utilities, drainage and slope. Check fire, coastal or historic rules that may apply. Gather any surveys, plans and utility records.
The output should be a written property check brief, not simply a yes/no statement. Open questions need owners and dates.
ADU Design and Engineering
Choose a standard, prefab or custom path only after checking the site. Set the room count, rough size and unit direction. Add privacy, access needs, finish level, energy systems and budget limit.
Order the plans, structural work and energy forms. Add a survey, soil work, drainage plan or expert review if needed. Owner changes are normal at this stage. Changes cost more time after engineering or permit filing.
ADU Permit Submission and Review
Prepare the site plan, building plans, math, energy forms and local filing. Submit the package and answer correction notes. Make sure all changed sheets agree.
Do not treat a legal review rule, program estimate or company experience as a firm permit date. Missing documents or design changes can add time. Review by more than one public office can also change the order.
ADU Utility Planning and Connections
Start utility work during design when possible. Do not always wait for the building permit. Check likely panel and service work, water and sewer routes, trenches and meters. Ask which utility forms are needed.
For context, LADWP’s electric meter-spot page says a visit is often set within 5–15 business days. Its water service page lists about 100 days for small service work. Rules, permits and crew schedules can change that time. Neither figure is a full ADU schedule or applies in every utility area.
ADU Pricing, Contracts and Material Orders
When the documents are stable, get written quotes based on the same plans and product details. Settle exclusions, allowances, utilities and permit duties before signing. Do the same for changes and payment stages.
Long-lead windows, electrical equipment, HVAC, cabinets, appliances or factory-built components may need early release. Confirm storage, deposits and duty if approvals change.
ADU Construction Stages
A typical build may start with setup, protection, demolition and digging. Underground lines, the base, frame, roof and dry-in follow. Then come rough systems, insulation, walls, finishes and fixtures. Outside work and repairs come near the end. Stages may overlap based on inspections, crews, products and site conditions.
Ask the builder for a schedule that identifies the items below.
- the contractual start trigger;
- owner choices and due dates;
- inspection points;
- utility dependencies;
- long-lead purchases;
- weather or access assumptions;
- substantial completion; and
- final inspections, approval records and the last payment.
ADU Inspections and Final Approval
Completion is more than the last coat of paint. Collect the final inspection or occupancy records that apply. Keep approved plans, warranty terms, manuals, lien releases and keys. Add test details, photos of hidden work if available and a finished repair list.
Confirm the address and utility account with the right office. Ask the right advisers about rent, insurance and tax. Do not assume the building contract covers these items.
Owner Decisions That Affect the ADU Schedule
Use one list for each choice, who makes it, details needed and due date. Examples include the plan, windows, power service, cabinet layout, tile and appliances. Add products bought by the owner.
Also keep an issue register for agency corrections, utility questions, unforeseen conditions and change orders. A transparent delayed choice is easier to manage than an invisible assumption.
Questions About Promised ADU Completion Dates
Be cautious when a schedule has any problem below.
- starts when building work begins but is presented as the complete project duration;
- assumes permits or utilities without written status;
- has no allowance for corrections or owner choices;
- is not tied to a defined list of work and contract;
- omits ordering and inspections; or
- promises an exact completion date before site review.
Speed has value, but only if the work and dependencies are visible.
Compare the schedule beside the Los Angeles California ADU cost guide. Acceleration may require extra design planning, early deposits, premium ordering or overlapping work. Those assumptions should be visible in both documents.
Frequently asked questions
How long does it take to build an ADU in Los Angeles?
There is no single reliable time. Company guides give a broad range of about 10–16 months for a full project. The actual time depends on the permit office, design, review and utilities. Orders, the builder and site conditions matter too.
Does a standard plan eliminate permit time?
Ask the reviewing office to identify the remaining plan, property and utility steps for the selected design. Include those tasks and any corrections in the schedule instead of assuming a pre-approved plan removes all permit work.
Should utility applications wait for the permit?
Not necessarily. Once the design basis and probable service need are clear, ask the relevant utility which steps can proceed in parallel.
What should the contract say about time?
It should identify start and completion terms, dependencies, owner obligations, permissible delays, change treatment and how schedule updates are communicated. Obtain legal advice for contract interpretation.