Garage Conversion ADU in Los Gatos - Plans, Permits & Build, One Fixed Price

Fast, Reliable Garage Conversion ADU Across Los Gatos

Garage conversion ADUs in Los Gatos typically run $180,000 to $310,000 all-in, from first soil test through final inspection. That is the honest range we quote for this town, where flatland bungalows and hillside estates each carry their own permitting realities. If your garage sits near downtown on a level lot, the price lands at the lower end. If it climbs into the Santa Cruz Mountain foothills, the geotechnical and fire-resistant construction requirements push it upward. Ellery ADU Studio has designed, permitted, and built garage conversions across Los Gatos since 2015, and our crews know the difference between a Blossom Manor lot and a Kennedy Road hillside before the first drawing is ever produced. Call (971) 497-2402 to schedule a free estimate.

Call (971) 497-2402

Why Ellery ADU Studio Is Los Gatos’s Preferred Garage Conversion ADU Company

Los Gatos homeowners come to us because we are one of the few design-build studios that puts a written price on a garage conversion before any work begins. That is Haven Standard Clause 1, and it means the $180,000 number we give you is the number you pay, not an opening bid. We have carried garage conversions through the Los Gatos Community Development Department for nearly a decade now, and we know which hillside parcels will trigger a geotechnical report and which flatland lots will not. Our track record in Los Gatos includes a 1920s Craftsman near Almond Grove where we found live knob-and-tube wiring behind garage walls, and a hillside detached garage off Blossom Hill Road where Chapter 7A fire-resistant cladding became a design driver. Neither project surprised the owner with a door-side change order. Both were priced in writing, with allowances written into the contract for exactly those discoveries.

Nadia Ellery leads the studio. Since 2015, Ellery ADU Studio has completed 900+ ADUs across the Bay Area, every one with a written price before work started and a documented photo record when work was complete. Los Gatos clients receive the same evidence on every visit, not a summary of how the day felt. Our crews are background-checked and uniformed. The license number appears on every page of our contract. And a live person answers our phones 24/7, no voicemail queue.

Our Garage Conversion ADU Services in Los Gatos

Detached Garage Conversion

A detached garage in Los Gatos is often the cleanest ADU path, especially on the post-WWII ranch lots in the flatlands where the structure already sits at the rear of the property. Los Gatos zoning allows detached conversions without the setback variances that new construction can trigger, but hillside parcels in the Very High Fire Hazard Severity Zone carry Chapter 7A requirements. We specify Class A roofing, ember-resistant vents, and ignition-resistant siding from the first draft, not as a correction after rough inspection. The permit set is the product. We produce it before we price the build.

Garage Partition & Bathroom Add

Some Los Gatos homeowners want a partial conversion: wall off two bays of a three-car garage, add a bathroom, and keep the remaining bay for storage. This is the most cost-efficient ADU form, often running in the $140,000 to $190,000 range depending on whether the existing slab can support plumbing. Los Gatos’s older detached garages near the Almond Grove and Old Town districts frequently sit on 4-inch slabs that require trenching for a new bathroom line. We price that trenching line-by-line, with the depth of the sewer connection confirmed before the contract locks. No surprises after signing.

Attached Garage Conversion

Attached garage conversions on Los Gatos hillside homes often involve irregular footprints and long utility runs that flatland projects never see. The town’s Community Development Department reviews fire separation between the new dwelling unit and the main house more strictly on hillside parcels. We handle that with a one-hour fire-rated assembly specified in the permit set, and we coordinate the electrical panel upgrade that nearly every mid-century Los Gatos home requires. If your home still has a 100-amp panel, plan for a service upgrade as part of the scope. We write that line into the contract on day one.

Garage JADU

A Junior ADU carved from an attached garage is the fastest path to a rentable unit in Los Gatos, capped at 500 square feet and generally permitted under a simplified review. Flatland homes east of Highway 17 are the best candidates, especially the ranch homes built in the 1950s and 1960s. Los Gatos allows JADUs with an efficiency kitchen and a shared or separate bath, and the town processes these faster than full ADU conversions. Ellery handles the JADU permit set, the conversion, and the documentation the assessor will need. Written price before any work begins, per Haven Standard Clause 1.

Trusted Brands We Service in Los Gatos

Ellery specifies and coordinates prefab and modular systems from Cover, Dvele, and Mighty Buildings within the same single contract. For a Los Gatos garage conversion, a Cover system can compress the construction timeline on a flatland lot where access is straightforward, while Dvele’s high-performance envelope suits hillside parcels facing Chapter 7A scrutiny. We do not resell these as separate packages. The prefab scope lives inside the same written price as the site work, the foundation, and the permit set, so the manufacturer and the builder cannot point at each other when something is off. We also maintain current specification data for James Hardie cladding, which we frequently use on Los Gatos hillside conversions to meet ignition-resistant exterior requirements.

Common Garage Conversion ADU Problems We See in Los Gatos Homes

Opening a pre-1960 garage in Los Gatos is a geology lesson and an archaeology lesson at the same time. Here is what we actually find, and how we handle it:

• Live knob-and-tube wiring in pre-1940 garages. Los Gatos garages near the Almond Grove and Old Town districts often still carry active knob-and-tube circuits that flatland quotes from Campbell or Santa Clara never anticipate. Current Title 24 requires replacement of any exposed knob-and-tube when walls are opened. We write an electrical replacement allowance into the contract before signing, so the upgrade is priced, not sprung.
• Asbestos board siding hidden under stucco. Detached garages in the Very High FHSZ that were built before 1978 frequently test positive for asbestos siding or decking. Removing it without a certified abatement plan will get the job red-tagged by the town. We include testing and, if needed, a written abatement allowance in the scope.
• Fog rot and failed waterproofing behind old drywall. Los Gatos sits at the mouth of the Santa Cruz Mountain passes. Hillside garages receive measurably more fog intrusion than the open valley floor, and sill plates rot behind walls where a visual inspection sees nothing. We price moisture-damaged framing repair line-by-line, with a documented photo log showing exactly what was found when the wall came open.
• Hillside applications rejected at permit intake for missing geotech. Los Gatos will not deem a hillside ADU application complete without a soils and geotechnical report stamped by a licensed engineer. That single requirement adds 6 to 10 weeks and $5,000 to $9,000 before design review even starts. We order the geotech report as the first deliverable, so your project does not idle at the permit counter.
• Chapter 7A compliance failures at rough inspection. Fall Diablo wind events funnel through the mountain gaps and spike fire risk, which is why such a large share of hillside Los Gatos carries the Very High FHSZ designation. Using non-ember-resistant vents or standard shingles on a hillside garage roof will force a redo. We specify Chapter 7A materials in the permit set itself, so the rough inspection passes on the first cycle.

Pricing for Garage Conversion ADU in Los Gatos, CA

Flatland garage conversions in Los Gatos run $180,000 to $240,000, drawings through final inspection. Hillside conversions with a geotechnical report, engineered foundations, and Chapter 7A materials run $260,000 to $310,000. A garage partition with a bathroom add on a flat lot can land around $140,000 if the existing slab cooperates. The big cost drivers in this town are the geotech trigger on hillside parcels, the fire-resistant cladding requirement in the Very High FHSZ, and the electrical service upgrades that pre-1970 homes almost always need. Every Ellery project gets a written price before work starts, with allowances written in for knob-and-tube wiring, asbestos, and fog rot. Call (971) 497-2402 to schedule a free estimate.

How Los Gatos’s Geotech Trigger Changes Your Garage Conversion

Here is the difference between a Los Gatos hillside ADU and the same project in Campbell or Santa Clara. Los Gatos’s Community Development Department will not deem your application complete without a soils and geotechnical report stamped by a licensed engineer. That means before anyone reviews a single design drawing, you have committed 6 to 10 weeks and $5,000 to $9,000 to a report that a flatland project never needs. We treat that report as a design input, not a bureaucratic hurdle. The geotech findings determine the foundation type, which determines the framing package, which determines the price. If the report reveals expansive soil or a shallow bedrock shelf, the foundation line item moves and we reprice that line before the contract locks, not after. Under Haven Standard Clause 5, the scope is locked at signing. The geotech report is how we make sure the locked scope is actually achievable. This is the single biggest reason a Los Gatos garage conversion quote differs from a Campbell quote, and it is why we never give a verbal price without seeing the parcel address first.

The Almond Grove Garage: What Opening Walls Actually Looks Like

On a 1920s Craftsman near the Almond Grove district, our crew opened a detached garage’s walls and found original knob-and-tube wiring still live, asbestos board siding hidden under stucco, and sill plates rotted by decades of Santa Cruz Mountain fog. The owner had received two flatland quotes that never mentioned any of it. We wrote a $14,000 contingency into the contract for electrical replacement, held daily photo logs for the owner, and priced the moisture-damaged framing repair line-by-line before touching it. The project passed Los Gatos inspection on the first cycle. That is how we work in this town: inspection first, allowances written into the contract, and any surprise priced and approved in writing before a tool comes out of the truck.

For a deeper look at the full scope of what we do, see our Garage Conversion ADU service hub, where we break down the design-build process, our finish packages, and the Haven Standard clauses that govern every project. And if you are weighing a conversion anywhere in the South Bay, our page on Garage Conversion ADU in Los Gatos covers this town in detail.

We Also Serve Cities Near Los Gatos

Beyond Los Gatos, Ellery ADU Studio serves Saratoga, Campbell, Cupertino, and Santa Clara. Each city has its own permitting quirks and soil profiles, and we price every project against the local code reality, not a regional average. If you live just over the Saratoga line or on the Campbell flatlands, the same written-price guarantee applies.

FAQs - Garage Conversion ADU in Los Gatos