The office in charge depends on the site. A City of Los Angeles project uses City steps. Other cities and unincorporated Los Angeles County have their own rules and filing systems. Confirm the permit office before choosing a plan or filing path.
Property Checks Before ADU Design
Do enough property review to confirm the legal lot and current buildings. Record the ADU type, usable space, access and utilities. Check for any mapped limits. Name who will obtain a survey or advice about structure, soil, trees, fire or historic rules.
The design brief should state the room count, size and planned use. Add privacy and access needs, finish level, budget and items bought by the owner.
What an ADU Drawing Package Includes
Project rules vary, but a complete package often uses the documents below.
- cover sheet, work and code details;
- current and planned site plans;
- area and zoning calculations;
- floor and roof plans;
- exterior elevations and building sections;
- door/window and finish details;
- foundation and framing plans/details;
- structural calculations where required;
- mechanical, electrical and plumbing details;
- Title 24 energy forms and supporting documents;
- drainage, grading or civil details where required; and
- manufacturer or deferred-submittal documents.
Ask the actual permit office for its current submission checklist and have the designer identify which items apply to this unit type and property. Record who prepares each document and who answers plan-check comments.
Who Handles ADU Design and Permit Coordination?
Ask for the legal name and role of each architect, engineer and designer. Do the same for the energy adviser, surveyor and permit contact. State whether the builder hires them or the owner must do so.
The agreement should identify the items below.
- number of concepts and revision rounds;
- who owns/reuses the drawings;
- site visits and measurements;
- consultant fees;
- agency submission and response duty;
- redesign triggered by budget or site details;
- construction-phase questions and revisions; and
- what happens if the building contract is awarded elsewhere.
What Pre-Approved ADU Plans Mean
Pre-approved programs need to be checked city by city and plan by plan. West Hollywood’s program FAQ limits its City plan to new detached construction and says changes beyond stated options need full review.
Pasadena’s program now distinguishes its older Eaton Fire-restricted catalog from an August 2026 studio plan offered for most single-family properties citywide. An older plan image is not proof of current eligibility.
For a City of Los Angeles project, ask LADBS to confirm the selected plan’s current status and remaining property review. Compare the work in the standard-plan guide.
ADU Plan Review and Corrections
A schedule should show the first filing and the check for missing items. Add local review, correction notes, the design team’s reply and refiling. Include other approvals, permit issue and any rule that must be met before work starts.
Ask the company to separate the stages below.
- statutory or agency review periods;
- its own response time;
- time waiting for owner choices;
- utility or outside-agency work; and
- total calendar duration.
Do not convert a review target into a guaranteed permit date.
ADU Permit and Consultant Costs
Separate fixed design fees from expert estimates, public fees and utility charges. List costs that the owner pays back to the company. Mark each amount as known, an allowance or paid by the owner.
If a design-build company advertises one total, ask what happens when plan review requires structural, utility or site changes. The cost guide provides the categories.
Plans and Specifications for ADU Construction Quotes
Early pricing can help with planning. A firm comparison needs a stable site plan, floor area and structural plan. It also needs finish details, utility assumptions and outside work. Give every bidder the same plan version.
Require an addendum log when drawings change. A company should confirm which dated set its price uses.
Who Applies for and Coordinates ADU Permits?
California CSLB guidance says a home-improvement contract should name who gets the permits. It should also name who attends inspections and answers correction notes. Assign later documents, added inspection fees and final approval records.
Use the builder comparison to record these duties.
ADU Design Changes After Permit Submission
Keep a list of each drawing, its date, the change made and who received it. If the owner, local office or site changes the design, name the affected sheets. Do this before work moves ahead.
A quote should say which replies to correction notes are included. It should explain how owner changes are priced. Name who checks that the crew has the current approved plans. Add these tasks to the complete ADU budget. A low design fee can grow if planning and changes are left out.
Require written distribution of each approved revision to the owner, site supervisor and affected trades.
Frequently asked questions
Does a permit expediter approve the project?
Ask the permit office to confirm who makes each approval decision, and ask the expediter to state exactly which submissions and communications are included in the fee. Keep design responsibility named in the agreement.
Can construction start while plans are being reviewed?
Before authorizing work, obtain the permit office’s written answer about the approvals needed for that exact phase. Ask the project team to list any proposed early work separately and identify the approval supporting it.
Is custom design always slower?
Not necessarily. A standard plan can be efficient on a compatible site. A custom plan may avoid repeated attempts to force an unsuitable footprint onto a constrained property.
Who should answer agency corrections?
The agreement should name the responsible designer or consultant and include a defined number or basis for correction responses.