Durham Region's Premier Builder

Residential Renovations Done Right

From kitchens to basements, Cornerstone Construction delivers professional renovations for homeowners across Oshawa, Whitby, Bowmanville, Ajax, Pickering, and Durham Region. Licensed, insured, and backed by our 8-point Certainty Stack.

Our Services

What We Build

Every service includes the full Cornerstone standard — white glove service, daily cleanup, price lock guarantee, and a 5-year warranty.

Kitchen renovation Oshawa Durham Region

Kitchen Renovations

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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Bathroom renovation Oshawa Durham Region

Bathroom Renovations

Full gut and rebuild, ensuite upgrades, powder rooms, heated floors, glass showers, and custom tile work. Starting from $15,000.

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Basement finishing Oshawa Durham Region

Basement Finishing

Family rooms, home offices, legal apartments, and guest suites. We finish basements that add real living space and real value. Starting from $40,000.

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General contracting Durham Region

General Contracting

Have a project that does not fit one category? We manage the full scope from design to handover. One point of contact. One contract. No surprises.

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Why Cornerstone

Why Durham Region Homeowners Choose Cornerstone

We built this company on one belief — homeowners deserve a contractor they can actually trust.

We Show Up

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.

We Lock Your Price

Your quote is your price. No surprise invoices. No change orders without your written approval.

We Back Our Work

Every renovation is covered by our 5-year workmanship warranty and a full Owner's Manual at handover.

Common Questions

Frequently Asked Questions

What areas do you serve?

We serve Oshawa, Whitby, Bowmanville, Clarington, Ajax, Pickering, Newcastle, Scarborough, Stouffville, and Peterborough.

How long does a kitchen renovation take?

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.

Do you use custom or pre-built cabinets?

Both. We work with custom and pre-built cabinetry depending on your budget and goals. We walk you through the options at your consultation.

Do you provide a warranty?

Yes. Every renovation is backed by a 5-year workmanship warranty and a full Owner's Manual at handover.

How do I get started?

Click Start Your Project Diagnostic, fill out the short form, and Mike will be in touch within 24 hours.

Do you pull permits?

When your project requires a permit we handle the entire process and tell you upfront what is needed and why.

Ready to Build Your Vision with Cornerstone?

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.

Licensed & Insured Ontario Corporation
Serving Durham Region Since 2017
5-Year Warranty on Every Job

What Our Clients Say

Real Results. Real Clients.

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."

Jolette Samuel — Kitchen Renovation, Oshawa

The Cornerstone Way

We Listen, We Build, We Deliver

Three phases. One team. One contract. No surprises.

01. Planning

We Listen

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.

02. Execution

We Build

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.

03. Completion

We Deliver

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.