Renovation Contractor in Oshawa & Durham Region
Renovation Contractor in Oshawa & Durham Region
From kitchens to basements, Cornerstone Construction delivers fixed-price renovations for homeowners across Oshawa, Whitby, Bowmanville, Ajax, Pickering, and Durham Region. Licensed, insured, and backed by our 8-point Certainty Stack.
Every service includes the full Cornerstone standard — white glove service, daily cleanup, price lock guarantee, and a 5-year warranty.
For homeowners who want a better kitchen without managing five different trades.
Custom and pre-built cabinetry, countertops, flooring, pot lights, plumbing, and electrical. We build kitchens that work as hard as you do. Starting from $25,000.
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For homeowners who want a bathroom that actually works, not just looks good in photos.
Full gut and rebuild, ensuite upgrades, powder rooms, heated floors, glass showers, and custom tile work. Starting from $15,000.
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For homeowners who want real living space out of the square footage they're already paying for.
Family rooms, home offices, legal apartments, and guest suites. We finish basements that add real living space and real value. Starting from $40,000.
Turning it into a legal apartment? Read Is My Basement Legal? first.
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For homeowners with a project that doesn't fit a neat category and needs one contractor running the whole thing.
Have a project that doesn't fit one category? From one-week flooring and wall-removal jobs to multi-month builds, we manage the full scope from design to handover. One point of contact. One contract. No surprises.
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For homeowners tackling multiple rooms at once who don't want to juggle separate contracts and separate trades.
Multi-room and full-home renovations done as one coordinated project — kitchen, baths, flooring, and finishes rebuilt to a single standard. One team, one contract, one timeline.
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For homeowners who need more square footage instead of more renovation inside the same walls.
Square-footage additions, second storeys, garages, and in-law suites. We extend your home without compromising structure, code, or the look of the original build.
Learn MoreWhy Cornerstone
We built this company on one belief — homeowners deserve a contractor they can actually trust.
Every residential renovation is backed by the Cornerstone Certainty Stack — eight written guarantees, not sales talk.
Mike Brock or a named supervisor is on your job every single day. You always know who is in charge and how to reach them.
Your quote is your price. No surprise invoices. No change orders without your written approval.
Every renovation is covered by our 5-year workmanship warranty and a full Owner's Manual at handover.
What Our Clients Say
Experience the Cornerstone difference through the words of homeowners we have served across Durham Region.
"Mike was the most professional and punctual contractor I have ever worked with. He understood how to bring my 10-year vision into reality. If it is not straight then it is not correct. He will make sure that it is. He will now be the only contractor to touch any part of my house."
Recent Projects
Real Cornerstone projects from start to finish — full scope, materials, and the problems we solved along the way.
Main Floor Renovation in Bowmanville
View project → OshawaCustom Kitchen Renovation in Raglan, Oshawa
View project → BowmanvilleWhole Home Renovation in Bowmanville
View project → ClaringtonMain Floor Renovation in Clarington
View project → OshawaMain Floor Condo Renovation in Oshawa
View project → WhitbyGourmet Chef's Kitchen in Whitby
View project → CourticeWhole Home Renovation in Courtice
View project →The Cornerstone Way
Three phases. One team. One contract. No surprises.
Before we touch a single wall we sit down with you. We learn how you use the space, what matters most, and what your budget can do. Then we build a plan around that.
Every trade on your job is vetted and held to our standards. Level 4 drywall. Daily cleanup. HEPA filtration. We build like it is our own home.
Your price is locked. Your timeline is committed. And when we hand the keys back you get a 5-year warranty and a full Owner's Manual. That is the Cornerstone standard.
Common Questions
We serve Oshawa, Whitby, Bowmanville, Clarington, Ajax, Pickering, Newcastle, Scarborough, Stouffville, and Peterborough.
It depends on the scope. Kitchens start at $25,000, bathrooms at $15,000, and basements at $40,000. You get a fixed, written price before any work begins — not an estimate that changes once we start.
Most kitchens take 3 to 8 weeks depending on the scope of work. We give you a detailed timeline before we start and hold to it. Our $300 per day on-time penalty means we are accountable if we run late.
Both. We work with custom and pre-built cabinetry depending on your budget and goals. We walk you through the options at your consultation.
Yes. Every renovation is backed by a 5-year workmanship warranty and a full Owner's Manual at handover.
Click Start Your Project Diagnostic, fill out the short form, and Mike will be in touch within 24 hours.
When your project requires a permit we handle the entire process and tell you upfront what is needed and why.
From Durham Region to the GTA, Mike Brock and our team deliver excellence. Book your free project diagnostic and get a fixed price before we start.
Durham Region's trusted renovation contractor. Led by Mike Brock since 2017. We Listen, We Build, We Deliver.
