ADU in Ontario - Plans, Permits & Build, One Fixed Price
We handle the design, the engineering, and the city permit, then build it. One contract, one crew, one accountable point of contact. Free feasibility check on your lot before you commit.
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What Our Clients Say
"The rental income has covered the payment since the second month. They were realistic about the numbers rather than optimistic."
"Handled the whole planning process. We went to one hearing and that was it."
"Detached unit in the back garden. Good design, good build quality, and the cost changes were documented and agreed in advance."
"Garage conversion finished on the drawings and close to the schedule. They were honest that the sewer connection was the unknown, and it was."
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.
Let's Fix Your ADU Fast
Prefer to talk now? Call us directly - we answer fast and dispatch even faster. No obligation, no sales pitch.
Call or Text(951) 577-3472Request A Free Quote
ADU Service Across the Ontario Area
We Are the Ontario Team for Ellery.
Ellery was founded in 2015, the year California's ADU law changed and the permitting queue became the actual product. It is a design-build studio rather than a contractor: the drawings, the permit set and the build are one contract with one price, because the ADU projects that go wrong are almost always the ones where the designer and the builder can each blame the other.
Same training, same parts, same pricing practice, and the same 365-Day Done Right Promise - delivered by people who live here.
Visit Ellery →Part of the Haven Family.
Haven is a family of home-service brands held to one written standard, and Ellery is the adu company in it. One promise stands behind every trade, in every town.