Pre-Approved ADU Plans: The Fast Lane, Honestly Mapped

The last advanced play is hiding in plain sight on your city's website. Under AB 1332, California cities must maintain pre-approved ADU plan programs — catalogs of designs already through plan check, posted online, with dramatically shortened review (recall lesson 5.10: ~30 days instead of the 60-day standard rounds).

How it works: the city (or partnered designers whose plans the city has blessed) publishes approved plan sets — typically a handful of studio-to-2BR designs. You pick one, and your application shrinks to the site-specific parts: the site plan (your lot, setbacks, placement — Module 2 never goes away), foundation verification for your soil, utility routing (Module 7 never goes away either), and Title 24 for your orientation. The building's design review is already done — that's the time savings.

What the fast lane genuinely delivers: permitting speed (the big one — weeks off the calendar); design cost savings (a fraction of custom design fees, since you're buying site-adaptation, not creation); and predictability (the plans have been through this exact city's checkers before — the correction cycles of Module 10 mostly pre-fought).

What it can't skip — the honest list: your site work is still yours (feasibility, survey if needed, soils triggers, utility design — Modules 2, 7, 9 apply in full; a pre-approved building on a problem site is still a problem project); fit is take-it-or-leave-it (meaningful modifications void the pre-approval and return you to standard review — the catalog is for lots the catalog fits); and construction costs don't change (the building still gets built at Module 6 prices — pre-approval compresses paper, not lumber).

The fit test: flat, unconstrained lot + a catalog plan that genuinely suits your goal (run it through Module 4's sizing and Module 8's design lens — being pre-approved doesn't make a plan right for you) + a premium on speed and design-fee savings = take the fast lane. Sloped or tricky lot, specific design goals, or a plan that fights your lot's utilities = custom design earns its fee (and lesson 11.2 helps you buy it well).

And with that, the advanced module closes. Legalization, multifamily math, unit stacking, lot splits, vertical builds, factories, and fast lanes — you now know the whole board, not just the standard opening. What remains is what happens after the building stands (Module 14), and the real projects that put all of it together (Module 15).