Pro Business

Cornerstone Construction

Oshawa Renovation Contractors
Ranked #9 in Oshawa | Grade C+
4.60 (20 reviews)

Cornerstone Construction

Cornerstone Construction is a local contractor focused on interior renovations, coordinating scopes and selections to deliver cohesive results. Communication and planning are emphasized to minimize disruption during the build.

Why Homeowners Choose This Business

Homeowners cite careful planning, consistent communication during the job, and attention to finish details. Estimates are discussed up front and selections are coordinated to match timelines. Site visits and progress check-ins help keep the scope aligned with expectations.

Service Area

Based in Oshawa and working across nearby Durham Region communities including Whitby, Bowmanville, and Ajax.


How This Business Compares

A quick local comparison based on ranking, review strength, and market visibility.
  • Has an established presence within this local market.

Services Covered

  Renovation Services
  Kitchen Renovation
  Bathroom Remodeling
  Basement Finishing
  Installations
  Flooring Installation
  Tile Installation
  Interior Carpentry
  Trim and Moulding
  Drywall And Painting
  Home Renovation Oshawa
  Durham Region renovations
  Kitchen and Bath
  Home Additions

Renovation services include: kitchen remodels, bathroom renovations, basement finishing, flooring and tile installation, interior carpentry and trim, drywall and painting, and project coordination with trade partners as needed.


Recent Reviews

4.60

(Based on 20 reviews)

Reviews commonly highlight clear communication, respect for timelines, and tidy workmanship throughout kitchen and full-home interior projects. Several customers describe organized planning and helpful guidance on finishes. A small number report slow response on initial follow-ups. Overall sentiment trends positive with many repeat recommendations.

Google Review
Jolette Samuel on Cornerstone Construction

REVIEW OF PROJECT: 1021

I have been renovating my home in small sections over the past 4 years. The most extensive and expensive was to be the full kitchen and new floor tiles starting from the front doors all throughout the first floor. It was a project I had quoted several times over the years with different contractors but none of them felt right, not to mention the wild quotes ranging from $27K to $90K.

I am now in the winter of 2024/2025. And the newly inaugurated orange clown to the south has started his "revenue generating" tariffs plan on Canada and other allied countries. Sigh. At first, I did not think much of it but when it started to sink it, a lightbulb went off in my head--this WILL affect me, too, so I started taking my kitchen remodel a lot more seriously.

I started the usual online search for contractors when I stumbled upon Cornerstone Construction on Facebook. I liked their ads so I decided to add them to my triple bid process. From the 3 options I sourced, Mike was the most professional and punctual. We had a 5pm appointment and true to his word, my bell chimed exactly at 5pm. He did not know this, but my home office looks out to the front of my house, so when I saw a truck pull up to the curb at 4:55pm, and the person remained in their vehicle until 4:59pm, I knew this person respects one’s time.

Not only was he very respectful of my home upon entry (removed shoes without being asked), he came prepared for taking notes, and actively listened. He understood how to bring my 10-year in the making vision into reality. We did weeks of design before I was satisfied and at no time did he rush me to make a decision. Once I confirmed the final drawing, work schedule, and initial downpayment, it was finally time for demolition-day on July 31st.

Throughout the entire process, Mike arrived on time every day we scheduled, provided daily walkthroughs and next steps, and cleaned up every time. If it’s not straight, then it’s not correct. He will make sure that it is. This is HIS standard, HIS level of perfection. His detailed eye mirrored my own. I had (and continue to have) complete trust in him. I did a small refresh of my ensuite a few years ago—new floor tiles, vanity, and toilet but knew the sunken tub and shower would require a greater teardown. I now have the perfect contractor to help me bring this vision to life as well. He will now be the only contractor to touch ANY part of my house...HOME.

WORK DONE:
-Installation of porcelain tiles
-Custom cabinetry
-Custom island
-Tons of new storage space
-New pot lights
-New wall tiles
-Pot filler

RATINGS
Professional: 10/10
Punctual: 10/10
Polite: 10/10
Knowledgeable: 10/10
Care of property: 10/10
Would I hire/work with again?: Yeeeessss!

Google Review
Mary Hawthorne on Cornerstone Construction

We had a great experience working with this general contractor from start to finish. Communication was clear, timelines were respected, and the quality of work exceeded our expectations. Every detail was handled professionally, and any questions we had were addressed quickly. It’s rare to find someone this reliable and skilled—highly recommend.

Called on Wednesday and spoke to a guy named Mike, seemed very friendly and informative. Asked me to send photos of my sink/island I wanted work done on.. was told he’d have a look at my text message the evening of cause he was currently at a job site. I followed up the following day asking if he’s had the chance to look at my photos-We’re not at the end of day Friday (evening) and still no response. Very poor service to say the least.

Google Review
Ryan Passmore on Cornerstone Construction

Project 1007 -
Mike completed a large renovation for us in Durham region,
The project was well done, the attention to detail really makes it appear well done.
Mike spends ALL of his time working on your project which makes it extremely easy to meet and review the project as it evolves.
We went ahead and created a finishes list to allow for proper ordering and timing, Mike also gives you a great template to start from, along with ideas on his original scope of what he would do or install. We found this helpful.

Overall a good experience,

Google Review
Joanne Cowles on Cornerstone Construction

I am so impressed with the quality of work and professionalism of this company. Right from the beginning Mike was very responsive - coming to my home to really understand what needed to be done to give me the results I wanted within my budget and making recommendations to maximize the space. I highly recommend this company for any project.

Write a Review

Share your experience with this business. Reviews are moderated before they appear publicly.


Frequently Asked Questions

Typical projects include kitchen remodels, bathroom updates, basement finishing, flooring and tile installation, and interior carpentry. The scope can range from single-room upgrades to multi-area interior renovations.

A site visit is scheduled to review the space and discuss goals, after which a written estimate is provided. Timelines are set based on material selections and scope, and progress check-ins help keep the schedule on track.

Yes, guidance is provided on finishes and fixtures to meet budget and style. Coordinating selections early helps align ordering lead times with the construction schedule.

Weekday hours generally follow an 8:00 AM to late afternoon schedule, with Friday ending earlier and weekends closed. Exact onsite times are coordinated with the homeowner for access and noise considerations.

Lead times vary by season and project size. Contacting the office a few weeks to a couple of months ahead typically allows time for site review, estimating, and material planning.
 Verified Listing

Opening Hours


  • Monday 8:00 AM – 5:00 PM
  • Tuesday 8:00 AM – 5:00 PM
  • Wednesday 8:00 AM – 5:00 PM
  • Thursday 8:00 AM – 5:00 PM
  • Friday 8:00 AM – 4:00 PM
  • Saturday Closed
  • Sunday Closed

Request Service


Business Details


Business Rating
4.60 (20 reviews) Pro Business
Address
804 Ritson Rd S rear unit, Oshawa, ON L1H 5L4, Canada, Oshawa, ON L1H 5L4
Phone
Business Type
general_contractor

Location Map

Own This Business?


Claim this profile, improve your listing, and upgrade to Pro or Featured visibility.

Claim This Business