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 Ontario
A garage conversion in Ontario typically runs between $85,000 and $165,000 for a full ADU with kitchen and bath, and most projects take 10 to 16 weeks from permit to final inspection. If you’re on a tight lot near the historic downtown or in an HOA subdivision on the east side, the real question is whether your garage can clear the city’s setback, parking, and design review rules without months of back-and-forth. Our team knows Ontario’s overlay zones, party-wall notice requirements, and work-hour ordinances, and we put every price in writing before any work starts. Call (831) 292-4191 for a free estimate and we’ll walk your specific lot before you spend a dollar on plans.
Why Lodgewick ADU Riverside Is Ontario’s Preferred Garage Conversion Contractor Company
Lodgewick ADU Builders is the ADU company of the Kingswell family, and we’ve been building garage conversions and accessory dwelling units since 2010. Homeowners in Ontario call us because we do something most contractors won’t: we hand you a written price before the first nail is driven, and we back every project with the 365-Day Done Right Promise. If the work isn’t right, we come back and make it right. That commitment is in writing on every single job.
Russ Delmar leads our crew and answers questions the way a neighbor would: straight, specific, and without a sales pitch. When you call about a garage conversion in Ontario, Russ or another live person picks up the phone, 24 hours a day. No voicemail loops. No chatbot. You’ll get a real arrival window and a clean job site, staged so your driveway and alley access stay usable while we frame, rough in, and finish.
We’ve worked with Ontario’s planning department, pulled permits for conversions near historic downtown, and coordinated party-wall notices with neighbors on tight lots. We know which subdivisions on the east side have CC&Rs that restrict ADU exterior finishes, and we check those before you pay for design work. That local knowledge keeps projects moving instead of stalled at the permit counter.
Garage Conversion ADU in Ontario
A Garage Conversion ADU in Ontario takes an existing attached or detached garage and turns it into a legal, rent-ready accessory dwelling unit with its own entrance, kitchen, bath, and heating and cooling. On many Ontario lots, this is the fastest path to rental income because the shell already exists, but the foundation, electrical service, and setbacks all need to clear the city’s current code, not the code from when the garage was built in 1963. A full Garage Conversion ADU here runs $95,000 to $165,000 depending on square footage, panel upgrades, and whether you’re adding a separate meter.
Attached Garage Conversion
An attached garage shares a wall with the main house, which saves on one foundation line and simplifies plumbing and electrical runs. In Ontario, attached conversions in older neighborhoods often trigger a party-wall notice if the garage wall sits on or near the property line. We handle that notice for you. Expect $85,000 to $140,000 for a one-bedroom attached conversion with a kitchenette and full bath.
Detached Garage Conversion
A detached garage gives you more separation and privacy for a tenant, but the rear-yard setback rules in Ontario apply hard here. Many detached garages were built 4 to 6 feet from the rear line, which is tighter than current code, so a minor variance may be needed. We’ve navigated that exact scenario near the historic downtown and can tell you early whether your detached garage is a clean conversion or a variance project. Budget $110,000 to $165,000 for a detached garage converted to a full one-bedroom ADU.
Garage Apartment Conversion in Ontario
A Garage Apartment Conversion in Ontario typically means converting the garage into a self-contained apartment with a private entrance, sleeping area, living space, kitchen, and bathroom, often above the existing footprint or within it. This is the preferred route for Ontario homeowners who want long-term rental income from logistics and warehouse workers who need housing near the distribution hubs. A garage apartment conversion in Ontario runs $120,000 to $180,000 when you’re adding a full kitchen, separate bath, and dedicated laundry hookups, and the number climbs if the garage has only a 60-amp subpanel that needs a 200-amp service upgrade.
Garage to Bedroom
If you don’t need a full apartment, converting a garage to a bedroom with an attached bath is a lower-cost way to add living space for an aging parent or adult child. Ontario permits this as living space without requiring a separate kitchen, which simplifies the permit and keeps costs down. Expect $60,000 to $95,000 for a garage-to-bedroom conversion with proper insulation, egress, and a ductless mini-split for Ontario’s hot summers.
Garage to Living Space
Converting a garage to open living space, a home office, or a playroom is legal in Ontario as long as you maintain parking per the city’s requirements for your zone. Many Ontario homeowners overlook parking replacement and get flagged at plan check. We verify your parking obligation before design work begins so you aren’t surprised by a stop-work order when the concrete trucks block an alley. A garage-to-living-space conversion typically costs $55,000 to $90,000.
Trusted Brands We Service in Ontario
When Ontario customers want a panelized or prefab ADU shell, we work with Cover, Dvele, and Mighty Buildings, each matched to the lot, budget, and timeline. Cover’s panelized system works well on Ontario’s flat lots with wide driveway access, while Dvele’s high-performance envelope makes sense for tenants who will run air conditioning through summers that regularly hit 100 degrees. We stock common electrical, plumbing, and HVAC parts in our Inland Empire yard so a missing breaker or valve doesn’t stall your Ontario conversion for a week. When a specific brand component is backordered, our team calls you the same day with an alternative and a revised price in writing.
Common Garage Conversion Contractor Problems We See in Ontario Homes
- Starting without checking the historic overlay. Ontario’s historic downtown has a design compatibility review that can deny a conversion if the new windows and siding don’t match the district’s character. We’ve seen homeowners lose six weeks when their permit was bounced back for missing a hearing. We file the design review paperwork before construction starts.
- Driveway parking mistakes on tight lots. If a garage conversion eliminates covered parking and your driveway can’t absorb the required replacement space, Ontario code enforcement can issue a stop-work order, often after a neighbor complains about trucks blocking the alley. We map parking and staging access during the estimate, not after the permit is pulled.
- Assuming the existing slab passes inspection. Many Ontario garages built in the 1950s and 1960s have slabs thinner than current frost-depth and termite requirements. If the slab fails inspection, we repour or reinforce a portion of it before framing, which adds cost but prevents a failed final inspection during a 100-degree week.
- HOA denials after city approval. East Ontario subdivisions with HOAs sometimes restrict ADU exterior finishes, roof pitches, or even the color of the front door. The city permit doesn’t override the CC&Rs. We pull your HOA’s design guidelines before we order materials so you aren’t paying for rejected siding.
Pricing for Garage Conversion Contractor in Ontario, CA
In Ontario, a basic garage conversion to finished living space starts around $55,000, a garage-to-bedroom with bath runs $60,000 to $95,000, and a full Garage Conversion ADU with kitchen and separate entrance lands between $95,000 and $165,000. A garage apartment conversion with dedicated laundry and a service upgrade typically runs $120,000 to $180,000. What moves the number in Ontario: whether the garage is attached or detached, how far the garage sits from the rear and side lot lines, whether the existing panel needs a 200-amp upgrade, and whether the lot is in a historic overlay or HOA-restricted zone. Every Lodgewick quote is written and line-itemed before work starts, and the price does not change at the door. Call (831) 292-4191 to schedule a free estimate on your Ontario property.
We Also Serve Cities Near Ontario
Our crews serve Ontario and the surrounding Inland Empire communities, including Montclair, Upland, Chino, and Mira Loma. If your property is in one of those cities, the same written pricing and 365-Day Done Right Promise apply. Learn more about our Garage Conversion Contractor services or see how we serve Garage Conversion Contractor in Ontario specifically.
Serving Ontario, CA - Our Local Coverage Area
We’re based in the Ontario 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 Ontario
Ontario generally allows the existing driveway to count toward required parking for an ADU, but only if it meets the city’s minimum dimensions for the zone and doesn’t create a backup hazard into a public alley or street. On many tight lots near the historic downtown, we’ve had to add a compact parking pad or file for a parking reduction. Our team checks your driveway dimensions during the free estimate and tells you exactly what the city will require. Call (831) 292-4191 and we’ll confirm it for your specific lot.
When a garage conversion touches or sits within a few feet of a shared property line, Ontario requires written notice to the adjacent property owner before certain permits are issued. The neighbor can respond with questions or objections, and the city may require a signed acknowledgment or a recorded easement. We prepare the notice, hand-deliver it when appropriate, and attend any city meeting with you. Budget about two to three extra weeks for the process. For an exact timeline on your lot, call (831) 292-4191 for a free estimate.
Ontario limits construction noise to weekday daytime hours, typically ending by early evening, and restricts noisy work on weekends and city holidays. That means framing crews start early and stop on schedule, which stretches a conversion by roughly one to two weeks compared to cities with looser rules. Our crews plan demo, concrete cutting, and roofing around those windows so your project doesn’t draw code enforcement complaints from neighbors on a quiet residential street.
Yes, in many cases. Ontario’s current code requires a garage ADU to have its own adequate service and dedicated circuits, and a recently replaced 100-amp house panel may still be too small to serve both the main house and a separate dwelling with a kitchen and air conditioning. We evaluate your panel amperage and load calculation during the estimate and tell you in writing whether a 200-amp upgrade is required before we quote the full job. Call (831) 292-4191 to get a written price that includes any panel work.
Yes. City approval in Ontario does not override a private HOA’s CC&Rs, and several east Ontario HOAs restrict ADU exterior designs, materials, or even roof forms. A city permit can be issued while the HOA design review is still pending, and the HOA can then deny the finish you planned. We pull the HOA’s design guidelines early, submit your plans to the HOA in parallel with the city application, and only order materials after both approvals are in hand. That sequence saves you from buying siding or windows you can’t install.
Russ Delmar and the Lodgewick team know Ontario’s setback rules, overlay zones, and the permitting path that gets a tight-lot garage converted to a rent-ready ADU without weeks of surprises. We put the price in writing before any work begins, we show up in the window we gave you, we leave the job site clean, and we back every project with a written guarantee. If the work isn’t done right, we come back and make it right. That’s the 365-Day Done Right Promise, and it’s on every Ontario project we build. Call (831) 292-4191 to schedule your free estimate.
Written by Russ Delmar, Owner at Lodgewick ADU Riverside, serving Ontario, CA since 2010.
