Cornerstone Construction

Cornerstone Construction Renovating shouldn't feel like a gamble. Kitchens, bathrooms & basements β€” Durham Region & GTA. We are located in Oshawa Ontario.

Cornerstone Construction's mission is to provide the highest-quality workmanship possible. We succeed at this because of the integrity of our subcontractors and staff, our commitment to a solid work ethic, and our passion for staying current with the newest innovations of our industry, with consideration for the environment. We have a full millwork shop providing custom millwork.

The new Site Protection blog just went up β€” Certainty Stack, Part 4. πŸ“–Nobody warns you about this part of a renovation. ...
09/28/2026

The new Site Protection blog just went up β€” Certainty Stack, Part 4. πŸ“–

Nobody warns you about this part of a renovation. Dust on the counters. Plastic sheeting where a door used to be. Half your house off-limits for weeks.

We built a real system for it instead of a broom and a shrug.

βœ”οΈ Sealed containment, every job
βœ”οΈ HEPA or negative air, sized to the work
βœ”οΈ Floor protection on every path we walk
βœ”οΈ A full daily reset before we leave

Your house should still feel like your house while we're in it.

Full guarantee is linked below. πŸ‘‡

β€” Mike

Picture a renovation with no mess.It's a Tuesday. Three weeks into the job.You get home from work. Shoes off. Walk to th...
09/28/2026

Picture a renovation with no mess.

It's a Tuesday. Three weeks into the job.

You get home from work. Shoes off. Walk to the kitchen.

The counters are clear. The floor's clean. No grey film on the couch.

Behind a plastic wall, a bathroom is being torn apart. You'd never know it.

That's the renovation I build.

After 35 years, I can tell you the part people dread isn't the price or the design. It's living in it. The dust. The boot prints. Plastic where a door used to be.

So the work zone gets sealed off before I swing a hammer. And every day before I leave, the space gets reset.

You cook dinner in your own kitchen. 🍽️
The kids do homework at their own table. πŸ“š

The renovation is happening. Your life isn't on hold.

If you've been putting it off because you can't picture living through it, start the conversation. We'll plan it so your house stays your house. πŸ‘‡

β€” Mike

πŸ‚ WEEKEND HOME TIPSFall's here β€” a few afternoon jobs now save you a bigger headache (and a bigger bill) come winter.βœ… C...
09/26/2026

πŸ‚ WEEKEND HOME TIPS

Fall's here β€” a few afternoon jobs now save you a bigger headache (and a bigger bill) come winter.

βœ… Clean out the gutters β€” clogged ones send water where it shouldn't go
βœ… Swap the furnace filter β€” your system works less, lasts longer
βœ… Drain and store the hose β€” a frozen hose bib is an easy fix to avoid
βœ… Check the weatherstripping on windows & doors β€” gaps let the heat (and your money) out

None of these take more than 20 minutes. All of them save you money.

Serving Oshawa, Durham Region & the GTA.

Hot Take Friday. 🎯Unpopular opinion: if a contractor won't put a specific warranty term in writing, that tells you more ...
09/25/2026

Hot Take Friday. 🎯

Unpopular opinion: if a contractor won't put a specific warranty term in writing, that tells you more than the number itself would.

It's not that they're hiding something shady. It's that "workmanship guaranteed" with no timeframe costs them nothing and commits them to nothing. It's a sentence built to sound reassuring and mean whatever they need it to mean later.

You wouldn't sign a lease with no end date. Don't accept a warranty with no term.

Ask for the number. In writing. Before you sign anything else. Full breakdown linked below. πŸ‘‡

β€” Mike

Throwback Thursday. πŸ”¨First renovation I ever did on my own, decades before Cornerstone existed β€” no fancy warranty langu...
09/24/2026

Throwback Thursday. πŸ”¨

First renovation I ever did on my own, decades before Cornerstone existed β€” no fancy warranty language, just my word that I'd fix it if something went wrong.

That's still basically the deal. We just put it in writing now, because a homeowner shouldn't have to take a stranger's word for it.

Same standard, on paper. Full breakdown of what's covered is linked below. πŸ‘‡

β€” Mike

Deep Dive Wednesday. πŸ“–1-year warranty vs. 5-year warranty. It sounds like a small difference. It isn't.MOST CONTRACTORS ...
09/23/2026

Deep Dive Wednesday. πŸ“–

1-year warranty vs. 5-year warranty. It sounds like a small difference. It isn't.

MOST CONTRACTORS (1 year):
❌ Covers the "settling in" period β€” the stuff that would've shown up anyway before they left
❌ Expires right around when real issues actually start surfacing β€” waterproofing that was subtly off, cabinetry settling into daily use
❌ Costs the contractor almost nothing to offer, because they're rarely still on the hook when it matters
❌ Often vague enough that what's "covered" is up for debate if you ever call

CORNERSTONE (5 years):
βœ… Covers the full window where real workmanship issues actually reveal themselves
βœ… Same terms in year 4 as year 1 β€” it doesn't quietly shrink over time
βœ… Costs us something real, because we're still liable long after the truck's gone
βœ… Specific enough in writing that you know exactly what's covered before you ever need it

Here's the part that makes 5 years possible in the first place: we don't cut corners where nobody's looking. Proper waterproofing systems behind every tile shower. Correct membrane and thin-set, not whatever's fastest. Real brands on fixtures, not no-name parts.

A 1-year warranty is easy to offer when you're gambling that most problems surface before you're gone. A 5-year warranty means we built it right the first time β€” because we have to.

Full breakdown linked below. πŸ‘‡

β€” Mike

Q&A Tuesday. πŸ”§"Does the warranty actually cost you anything, or is it just words?"Fair question. Here's the honest answe...
09/22/2026

Q&A Tuesday. πŸ”§

"Does the warranty actually cost you anything, or is it just words?"

Fair question. Here's the honest answer: yes, it costs us something. That's exactly why it works.

A one-year warranty costs a contractor almost nothing β€” most problems that surface come with the punch list anyway. Five years means we're still on the hook long after the truck's gone and the next job's started.

That's not a marketing number. It's a bet we're making on our own work.

βœ… We eat the cost if something fails
βœ… You don't chase us for it
βœ… Same terms whether it's month 2 or year 5

Ask me anything about how a renovation actually works β€” drop it below.

β€” Mike

The new Warranty blog just went up β€” Certainty Stack, Part 3. πŸ“–Most renovation warranties are one sentence long, on purp...
09/21/2026

The new Warranty blog just went up β€” Certainty Stack, Part 3. πŸ“–

Most renovation warranties are one sentence long, on purpose. Vague costs the contractor nothing to offer, because nobody can ever prove what it was supposed to mean.

We do the opposite.

βœ”οΈ 5 years β€” five times the industry standard
βœ”οΈ Specific enough you know exactly what's covered
βœ”οΈ In writing, before you ever need it
βœ”οΈ Backed by a company that's still around to honour it

A warranty you can only use if you can prove what it meant isn't really a warranty.

Full breakdown linked below. πŸ‘‡

β€” Mike

After 35 years, here's what I've learned about a good renovation:It's not done when the last cabinet goes in.It's done w...
09/21/2026

After 35 years, here's what I've learned about a good renovation:

It's not done when the last cabinet goes in.

It's done when you stop thinking about it β€” because you know it's covered.

Every job I hand over comes with five years behind it, in writing. Not because I might need it. Because you shouldn't have to wonder.

That's the part nobody shows you in the before-and-after photos. The part where you just... live there. No what-ifs.

That's what I actually build.

β€” Mike

✨ INSPIRATION SUNDAYOut of every project I've built, the ones I'm proudest of aren't the biggest.They're the ones where ...
09/20/2026

✨ INSPIRATION SUNDAY

Out of every project I've built, the ones I'm proudest of aren't the biggest.

They're the ones where the homeowner never once had to wonder what something was going to cost.

That's not an accident. It's a number I locked in before we ever picked up a tool, and it's the same number they paid at the end.

You deserve to enjoy watching your space come together, not braced for a call about the budget.

Address

Oshawa, ON

Opening Hours

Monday 8am - 5pm
Tuesday 8am - 5pm
Wednesday 8am - 5pm
Thursday 8am - 5pm
Friday 8am - 4pm

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