Existing records
Identify the legal use and permitted status of the main home, garage, additions, and other structures.
Field note 01 · Requirements
Fullerton ADU requirements start with current sources.
A useful requirements review connects statewide ADU law, Fullerton’s current pages, the property record, and the proposed scope. It does not treat one old bulletin as a universal answer.
01 · Code baseline
Confirm which standards govern the submission.
Fullerton’s current building-codes page states that the 2025 California codes and Fullerton amendments apply to projects submitted on or after January 1, 2026. Check the current City ADU page and California HCD handbook alongside the code edition.
Source checkpoint
Older City documents can explain background, but they should not silently replace the current code and live instructions.
02 · Property read
Requirements become real on the site plan.
Placement
Map lot lines, structures, easements, grade, access, trees, and likely fire and construction paths.
Utilities
Trace likely sewer, water, electrical, drainage, and meter work before calling a layout settled.
Unit program
Define intended use, target size, privacy, parking conditions, accessibility goals, and storage needs.
03 · Pre-design questions
Resolve the high-impact unknowns first.
Which ADU type fits?
Detached, attached, conversion, and junior units interact differently with existing construction and daily use.
What needs verification?
List every record, dimension, utility route, and agency answer the concept currently assumes.
What belongs in the package?
Use the City’s current forms and bulletin library to identify project-specific drawings and supporting documents.