Mistakes and checklists
ADU preparation mistakes to avoid
Most ADU setbacks start before drawings: a design chosen before the lot is understood, utilities assumed, or records not checked. Each mistake below comes with the check that prevents it.
What matters
Why preparation decides the project
Feasibility answers — overlays, access, utilities — change which ADU type and size are worth drawing.
Local facts matter here
Each authority publishes its own ADU guidance; start from the permit page for your city.
Use the checklist, then talk
Bringing these answers to a consultation makes the first conversation about your lot, not generalities.
Comparison
Scroll the table sideways on small screens.
| Mistake | Consequence | Check first |
|---|---|---|
| Choosing a model before the lotFeasibility record → | Redesign after feasibility. | Parcel overlays and site plan. |
| Assuming utilities extend easilyUtility coordination → | Budget and schedule surprises. | Sewer, water and power routes with providers. |
| Ignoring garage permit historyGarage condition log → | Documentation or correction work. | Permit records at the authority. |
| Forgetting construction accessAccess comparison → | Slower, costlier site work. | Side-yard width, trees, slopes. |
| Treating pre-approved plans as site approvalWhat the authority still reviews → | Unexpected site review. | Ask what the authority still reviews. |
How to decide
Before you rely on a checklist
- Each check produces a question for the reviewing authority or a professional, not an approval.
- Statewide ADU rules apply through your local authority; read its current materials and note the date.
Hypothetical: an owner buys detached-unit plans online, then learns the only construction path is a shared driveway with an easement question. Recording access first would have changed which plans were worth buying.
Questions
- Where do I start checking my lot?
- The permit page for your city lists the official lookup tools and ADU guidance.
Where the facts come from
Educational, not a service offer
These pages explain decisions in general. Service pages by community describe KB's work in a specific place; permit pages describe each authority. Nothing here confirms what applies to your parcel.
Discuss this with KB →This page sends nothing. On the contact form you choose what to share.
KB Remodeling · Greater Los Angeles
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