ADU Permits in Los Gatos

Los Gatos is one of the few Bay Area cities where I tell clients the permit process itself isn’t the hard part, the siting is. If your lot is flat and in a standard residential zone, the town’s process is a fairly ordinary ministerial review. If your lot is anywhere in the hills, there’s a real procedural step most other cities don’t have, and skipping past it mentally is how projects lose a month.

That step is the Least Restrictive Development Area, or LRDA, and I’ll get into exactly what it requires below. First, what’s actually changed here for 2026.

What Changed for Los Gatos ADU Permits in 2026

Start with the fact that Los Gatos is rewriting its own ADU ordinance right now, not just tweaking a fee schedule. The town’s ADU ordinance, Town Code Chapter 29, Article I, Division 7, dates to a 2020 update (Ordinance 2307), and California’s Housing and Community Development department sent the town a formal findings letter on it back in October 2023. The Planning Commission reviewed a draft rewrite on June 10, 2026, and forwarded a recommendation to Town Council, with Town Council review currently scheduled for August 4, 2026 according to the town’s own ADU information page. That date can move, so confirm current status with the Planning Division before you finalize anything based on rules you read today, this page included.

Here’s why that rewrite carries more weight than it would have a few years ago. A 2025 amendment to SB 9 gave HCD the authority to declare a noncompliant local ADU ordinance null and void, at which point the jurisdiction falls back to bare state standards until it adopts something that passes muster. Los Gatos already has an open HCD findings history. That’s the actual pressure behind this rewrite, not just routine housekeeping.

Separately, four state bills took effect January 1, 2026, and they apply in Los Gatos regardless of where the local rewrite lands. SB 543 shifts ADU size measurement to interior livable space, sets a 15-day completeness-check clock on applications, and expands the impact fee exemption to any ADU at 750 square feet or less (500 or less for a JADU). AB 1154 narrows JADU owner-occupancy requirements to units that share a bathroom with the main house. AB 462 mostly touches coastal-zone and disaster-rebuild permitting, which has limited bearing on a landlocked town like Los Gatos. The 2025 SB 9 amendment giving HCD teeth is the fourth, and it’s the one that actually matters most here given the town’s history.

On the fee side, the town’s Community Development Department fee schedule went into effect July 1, 2026, and it’s what I’m citing for every fee figure below.

How the Los Gatos ADU Permit Process Works

ADU permits in Los Gatos run through the Community Development Department, split between the Planning Division (zoning and site compliance) and the Building Division (the actual construction permit and plan check). Both work off a single, unified ADU/JADU application rather than sending you through separate planning and building submittals, which is a genuine convenience compared to cities that stack those as two distinct processes.

Submission happens through the town’s online permit portal at permits.losgatosca.gov, which now runs on the getAPERMIT platform after the town moved off its older Accela Citizen Access system. The town has gone fully digital: no paper plan submittals are accepted anymore. You submit site plans, architectural plans, structural plans, a utility and load plan, and Title 24 energy documentation together as one package.

Once submitted, staff checks the application for completeness, then it moves through a single combined plan review covering zoning, building, and applicable specialty trades. Because ADUs are reviewed ministerially under Town Code Section 29.10.305, there’s no public hearing and no discretionary Architecture and Site review, the same protection state law requires everywhere in California. Corrections are normal on a custom design; expect at least one round.

If your lot sits in the Hillside Residential (HR) or Resource Conservation (RC) zone, there’s an added front-end step. Before your site plan can even be finalized, a site-specific constraints analysis has to map the Least Restrictive Development Area, the portion of your lot where the town’s 2004 Hillside Development Standards and Guidelines say building is actually appropriate. That analysis looks at slope (the LRDA framework uses a 30 percent slope threshold as one of its criteria), access, and geologic hazard conditions. This isn’t something the standard ADU application portal walks you through automatically; it’s typically prepared by a civil engineer or geologist working from the town’s hillside standards before the site plan goes in. Los Gatos hasn’t published a specific week count for how long this adds, so I won’t invent one. Budget real time for it regardless, and don’t let a designer talk you into skipping straight to a floor plan on a hillside lot.

Water and electric connections are handled outside the town entirely. San Jose Water Company serves Los Gatos, and PG&E handles electric. Neither the town’s utility information page nor its ADU materials publish a specific ADU capacity determination process the way some cities do, so treat that as unverified and call the utility directly before you assume your existing meter or panel can carry a second unit.

Sewer is the one utility step that’s genuinely worth flagging, because it’s easy to miss. Los Gatos sits within West Valley Sanitation District, a separate special district from the town, and it requires its own permit for an ADU, not just a line item on the town’s bill.

Los Gatos ADU Permit Fees (2026)

Fee	Amount	Notes
Use and occupancy clearance (new secondary dwelling unit)	$0	Verified waiver, Town fee schedule effective July 1, 2026
Building permit issuance and plan check	Valuation-based	Unverified exact figure; no flat published schedule, confirm with the Building Division
State development impact fees	$0	For ADUs at or under 750 sq ft (500 sq ft for a JADU), per SB 543
WVSD sewer permit processing	$250 to $800	Depends on whether a new sewer lateral is needed
WVSD sewer capacity buy-in (detached ADU)	Up to $568 per drainage fixture unit, capped at $6,800, plus up to $87 per unit capped at $1,100 for treatment capacity	ADUs built within an existing building are exempt from this buy-in
WVSD monthly sewer service charge	$35 to $400 (prorated)	Varies by unit size and fixture count

Source: Town of Los Gatos fee schedule effective July 1, 2026 (losgatosca.gov/DocumentCenter/View/217); West Valley Sanitation District permit information (wvsdca.gov)

I want to be straight about that table the same way I was on the Los Gatos cost page. The town’s own Community Development Department fee schedule covers Planning Division applications almost entirely, and the one ADU-specific line on it is the use and occupancy clearance fee, waived outright. What it doesn’t have is a flat building permit or plan check number, because the Building Division calculates that off construction valuation rather than publishing it as a static figure. I’m not going to hand you a made-up total dressed up as fact. Confirm your actual number with the Building Division at Building@LosGatosCA.gov or (408) 354-6876 before you finalize a budget.

Los Gatos ADU Permit Timeline by Phase

Phase	Duration	Department
LRDA constraints analysis (hillside/HR/RC lots only)	2 to 6 weeks	Prepared pre-submittal, reviewed by Planning Division
Application intake and completeness check	1 to 2 weeks	Community Development Department
Plan check, standard flat lot	3 to 6 weeks	Planning & Building Divisions
Plan check, hillside/LRDA-constrained lot	6 to 12 weeks	Planning & Building Divisions
Corrections and recheck	2 to 4 weeks	Building Division
WVSD sewer permit (can run in parallel)	Up to 10 business days	West Valley Sanitation District
Permit issuance	Under 1 week	Building Division

Source: Builder-experience estimate; Los Gatos has not published its own phase-by-phase timing, state ministerial review timing per Gov. Code 65852.2 as amended by SB 543

Add it up and a straightforward, flat-lot application can realistically get a permit in four to eight weeks, which lines up with what I’ve quoted on the Los Gatos cost page. A hillside lot that needs the LRDA constraints analysis first, plus a longer plan check because siting isn’t a simple setback check anymore, is more honestly ten to sixteen weeks before construction starts, sometimes longer if the constraints analysis turns up something that reshapes the site plan.

The Los Gatos Pre-Approved Plan Gallery

Los Gatos runs a pre-approved ADU plan gallery under California’s AB 1332 program, hosted at the town’s own ADU accelerator site and cross-linked from its ADU information page. Picking one of these plans means you’re building a design HCD and the town have already cleared for structural and code compliance, so you skip paying for and waiting on a fresh architectural plan check.

The town states its limitation plainly: once you select a pre-approved plan, no modifications are allowed, no matter how minor. That’s a real constraint, not a formality.

Here’s why that matters more in Los Gatos specifically than it would in a flat-lot city. On a standard R-1 or R-D lot, picking a catalog plan and dropping it into a buildable rectangle is usually straightforward. On an HR or RC hillside lot governed by the LRDA, the plan still has to sit inside whatever buildable envelope the constraints analysis identifies, and a fixed, unmodifiable footprint often doesn’t fit that envelope without a site-specific supplement anyway. At that point you’ve lost a meaningful chunk of the time savings the pre-approved path is supposed to give you. I’d treat the plan gallery as a strong option for flat lots and a genuinely weak fit for anything in the hills until you’ve already run the constraints analysis and know your buildable area.

Los Gatos-Specific Rules That Trip People Up

Hillside siting runs through the LRDA, not standard setbacks

Under Town Code Section 29.10.320(3)(d), ADUs in the HR and RC zones don’t use the flat four-foot side and rear setback that applies everywhere else in town. Instead they have to sit within the Least Restrictive Development Area identified through a slope, access, and geologic constraints analysis. Your ADU’s location on a hillside lot isn’t really a design choice until that analysis is done.

The historic district trades easier parking for tighter siting

Downtown Los Gatos has a genuine Landmark and Historic Preservation combining district. Town Code Section 29.10.320(8)(a)(2) exempts ADUs inside a historic district from the off-street parking requirement entirely, which is a real savings. The trade is that you can’t site the ADU in front of a primary dwelling that’s a designated historic resource.

The sewer capacity buy-in is a separate district’s bill, not the town’s

West Valley Sanitation District is its own agency, not part of the Community Development Department, and its capacity buy-in fees on a detached ADU don’t show up anywhere on the town’s own fee schedule. I’ve seen homeowners budget off the town’s fee page alone and get surprised by a separate WVSD invoice that can run into the thousands depending on fixture count.

The rules you’re reading might not survive the rewrite

Because Los Gatos is actively rewriting Chapter 29’s ADU division right now, with Town Council review currently on the calendar, don’t treat any local rule cited here, or anywhere else, as permanent for the year. Confirm the current adopted version with the Planning Division before you commit a design to it.

What I’d Do If I Were Permitting in Los Gatos Right Now

If my lot is flat and in a standard zone, I’d check the pre-approved plan gallery before spending money on a custom design, since the process savings are real there. If my lot is anywhere in the hills, I’d order the LRDA constraints analysis before I let anyone finalize a floor plan, pre-approved or custom, because siting decides the design here more than the design decides the siting.

I’d also call West Valley Sanitation District early to get a real number on sewer capacity buy-in for a detached unit, rather than finding out at invoice time, and I’d check in with the Planning Division on where the ordinance rewrite stands before I assumed today’s rules hold through construction. For the full build budget rather than just the permit line, the Los Gatos ADU cost breakdown has the fuller numbers, including what hillside lots typically add on top of the permit fees themselves.

Frequently Asked Questions

How long does an ADU permit take in Los Gatos?

Realistically four to eight weeks for a complete application on a flat, standard-zone lot, or ten to sixteen weeks if your lot needs an LRDA constraints analysis first. Los Gatos hasn’t published its own phase-by-phase timeline, so both ranges are builder-experience estimates, not official figures.

What department handles ADU permits in Los Gatos?

The Community Development Department, split between the Planning Division for zoning and site compliance and the Building Division for the construction permit and plan check. Both work off one unified ADU/JADU application rather than separate submittals.

Does Los Gatos waive any ADU permit fees?

Only the use and occupancy clearance fee, which is $0 per the town’s own fee schedule effective July 1, 2026. Beyond that, the only impact fee relief is the state’s own SB 543 exemption for ADUs at 750 square feet or less, the same floor every California city has to honor.

What is the LRDA and when does it apply?

The Least Restrictive Development Area is the buildable envelope a constraints analysis identifies for hillside lots in the HR and RC zones, based on slope, access, and geologic conditions, under Town Code Section 29.10.320(3)(d). It applies instead of the standard four-foot setback and generally needs to be worked out before your site plan can be finalized.

Does Los Gatos have pre-approved ADU plans?

Yes, through an AB 1332 plan gallery hosted at the town’s own ADU accelerator site. Modifications aren’t allowed once you pick one, which makes the gallery a strong fit for flat lots and a weaker one for hillside lots where the LRDA may force a different footprint anyway.

If you’re comparing Los Gatos against the market next door, our San Jose ADU permit guide covers a city with a much more mature pre-approved plan program and a completely different, hourly fee structure. Our California permit overview covers what applies regardless of which Santa Clara County city you’re in, and the permits pillar and Data Hub are the right next stops for comparing markets more broadly.