







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable Garage Conversion Contractor Across South San Jose Hills
Garage conversions in South San Jose Hills run $120,000 to $180,000 for a standard attached garage turned into a studio or one-bedroom living space, with detached conversions typically adding $15,000 to $25,000 for utility trenching and new foundation work. We handle the full process, from LA County plan check through final inspection, so the unit is legal, comfortable, and built to last. Our crews know the unincorporated LA County process cold, because that is the only process that applies here. Call (361) 315-4177 to get a written price before any work starts.
Why Fielding ADU Builders Is South San Jose Hills’s Preferred Garage Conversion Contractor Company

We are part of the Garage Conversion Contractor team at Fielding ADU Builders, and we work under The Garrison Standard: a written price before any work starts, permitted work done by the book, and a one-year written guarantee covering workmanship defects. That standard has been in place since Garrison Partners was founded in 2006, and it applies to every job we take in South San Jose Hills, no exceptions.
South San Jose Hills homeowners tell us the same story: they hired someone who missed the schedule, moved the price at the door, or left the permit board blank. We do not do any of that. The price you approve on day one is the number on the final invoice. Every crew member is background-checked and uniformed, so you know exactly who is on your property. And when you call, a live person answers, 24 hours a day, 7 days a week. No voicemail, no callback queue.
Reed Calloway leads our team, and he holds every project to the same standard: show up in the window, price in writing, by the book, leave it clean, stand behind it for a year. That is The Garrison Code, and we do not deviate from it.
Garage Apartment Conversion in South San Jose Hills
Garage Apartment Conversion in South San Jose Hills means turning an existing garage into a self-contained living unit with its own entrance, bathroom, kitchenette, and sleeping area, permitted through LA County Public Works Building & Safety as an ADU. For a standard two-car garage of roughly 400 square feet, expect to pay between $130,000 and $175,000 in South San Jose Hills, depending on the condition of the existing slab and roof structure. We start with a structural review before we quote, because hidden rot or an undersized foundation changes the scope fast.
Detached Garage Apartments
Detached garage conversions add trenching for water, sewer, and electrical lines, plus insulation and usually a mini-split heat pump. We converted a detached two-car garage on a cul-de-sac near Valley Blvd and Nogales Street into a 420 sq ft garage apartment for an owner adding space for family. Our crew framed a new insulated wall, added a bathroom DWV tie-in, and ran a 60-amp subpanel from the main service, using James Hardie siding and a mini-split for efficiency. After LA County plan check and inspections, the unit was signed off as a legal ADU.
Attached Garage Apartments
Attached conversions share existing walls and roof lines, which reduces foundation and exterior work but still calls for separating the unit from the main house with a fire-rated wall. Most attached garage apartments in South San Jose Hills run $120,000 to $155,000 before permit fees, depending on whether the existing electrical panel can carry the added load or needs an upgrade from 100A to 200A.
Garage Conversion Permit in South San Jose Hills

Garage Conversion Permit in South San Jose Hills is issued by LA County Public Works Building & Safety, not the City of San Jose, because South San Jose Hills is unincorporated LA County. Plan check happens at the county level, and so do the inspections. That means the permit timeline, the forms, and the review comments all follow LA County’s ADU ordinance, including its setback and height standards. If you submit drawings that assume city jurisdiction, plan check will reject them, and you will pay for redesign.
Setbacks and Height Limits
LA County’s ADU ordinance sets specific side-yard and rear-yard setbacks, as well as building height limits, and those rules apply to your garage conversion even if the existing structure has been there for decades. A detached garage that is already close to the property line may need a setback variance (the county’s written permission to build closer to the line than the standard rule allows), which adds review time and cost. We check this before we draw, not after plan check sends it back.
Electrical and Structural Plan Check
Count on LA County asking for a load calculation on your existing electrical service. Many South San Jose Hills homes built in the 1960s and 1970s still run on 100A panels, and a garage apartment with a mini-split, water heater, range, and laundry will push past that. Upgrading to a 200A service or adding a subpanel is a common mid-project cost driver that homeowners who got a cheap quote did not see coming. We build it into the written price from the start.
Trusted Brands We Service in South San Jose Hills
We work with the major prefab and modular ADU platforms South San Jose Hills homeowners are already researching, including Abodu, Cover, and Dvele, alongside conventional builds using James Hardie siding. That gives you a real choice: a panelized system that goes up faster, or a stick-built conversion that matches the existing house. We stock the common trim, flashing, and siding profiles for South San Jose Hills jobs, so material lead times do not stall a project mid-framing. When you call (361) 315-4177, we can walk you through which build method fits your budget and lot, before you commit to anything.
Common Garage Conversion Contractor Problems We See in South San Jose Hills Homes
- Plan check rejects drawings that ignore county jurisdiction. South San Jose Hills is unincorporated LA County, so LA County Public Works reviews the plans. Contractors who assume City of San Jose rules submit drawings that fail on setbacks, height limits, or missing owner-builder forms, and the homeowner pays for the redesign.
- Electrical service is undersized for a living unit. Older homes in the area still run 100A panels, and a garage apartment with a mini-split, water heater, and cooking appliances will overload that. If the load calculation is not done early, the panel upgrade shows up as a surprise change order mid-framing.
- The slab or roof structure is not checked before quoting. Hidden rot in the roof framing or an undersized slab foundation forces structural repairs after demolition starts. We do an engineering review before we put a number in writing, so the price you approve includes what the structure actually needs.
- Setback variances get ignored until it is too late. A detached garage near the property line often needs a setback variance under LA County’s ADU ordinance. That variance adds review time and can change the buildable footprint. We flag it at the first site visit, not after the plans are drawn.
Pricing for Garage Conversion Contractor in South San Jose Hills, CA
Most garage conversions in South San Jose Hills land between $120,000 and $180,000 before permit fees. A simple attached garage to living space with an existing bathroom nearby starts closer to $120,000. A detached garage apartment with a new bathroom, kitchenette, subpanel, and utility trenching runs toward $180,000. What moves the number: electrical panel upgrades, foundation repairs, setback variances, and the finish level you choose. We give you a written line-item price before any work starts, and the number you approve on day one is the number on the final invoice. Call (361) 315-4177 for a free estimate, and we will break down the ranges for your specific garage.
We Also Serve Cities Near South San Jose Hills
Beyond South San Jose Hills, we serve homeowners in Los Angeles, Long Beach, Anaheim, and Riverside. Each area has its own permitting authority, and we handle the paperwork for whichever jurisdiction applies. If you are on the edge of South San Jose Hills, call us and we will confirm which agency reviews your plans.
Serving South San Jose Hills, CA - Our Local Coverage Area
We’re based in the South San Jose Hills area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Garage Conversion Contractor in South San Jose Hills
Yes. South San Jose Hills is unincorporated LA County, so your garage conversion is permitted and inspected by LA County Public Works Building & Safety, not the City of San Jose. We prepare drawings and forms for LA County plan check and handle every inspection through final sign-off. Call (361) 315-4177 for an exact quote; estimates are free.
A standard attached garage conversion takes 3 to 5 months from design to final inspection. Detached conversions with utility trenching and a new foundation run 4 to 6 months. LA County plan check typically takes 4 to 8 weeks, and we sequence the work so the build starts while final approvals are in hand. We will give you a written schedule with the price.
Many homes in South San Jose Hills still run 100A panels, and a garage apartment with a mini-split, water heater, and cooking appliances will usually require an upgrade to 200A or the addition of a subpanel. We run the load calculation during the quoting phase, so the cost is in the written price, not a surprise later. Call (361) 315-4177 to schedule a free estimate.
Yes. LA County’s ADU ordinance allows garage conversions to be rented as long as the unit meets building, fire, and health standards and passes county inspections. We build to those standards and get the unit signed off as a legal ADU, which protects you if a tenant or buyer ever questions the paperwork.
The three common ones are an undersized electrical panel, hidden rot or foundation problems, and a setback variance required by LA County. We find all three during quoting, before work starts, so they are in your written price. If the structure or the site changes after demolition reveals something genuinely unknown, we tell you in writing before any extra work is done. Call (361) 315-4177 and we will walk you through the specific risks on your property.
Written by Reed Calloway, Owner at Fielding ADU Builders, serving South San Jose Hills and surrounding LA County communities since the company’s founding within Garrison Partners in 2006.



