I live in an 80's condo in Redondo Beach that needed updated patio doors, as the existing ones I were warped aluminum, not insulated, etc. I received... Open

Since they only just finished the job, I cannot comment on the quality of windows we purchased from Cornerstone, OR any warranty-related issues. What I CAN... Open

Since they only just finished the job, I cannot comment on the quality of windows we purchased from Cornerstone, OR any warranty-related issues. What I CAN say is that their staff is professional and a pleasure to work with. The installation was on time and ALL their installers as polite as they were professional. Because we were so happy with dealing with Cornerstone, we cannot comment on "value" because we didn't bother getting prices from anyone else. Open

I wanted to let everyone know that this window company is awesome. They took out and installed 6 windows in 2 hours. I have never seen anyone work this... Open

From their Yelp reviews, I knew they'd be good. But still, I was apprehensive (meaning scared half to death). Because....I've replaced window glass before... Open

Tony and his crew did an awesome job on our home! Had all 13 windows and 3 sliders replaced and couldn’t be happier. I would definitely recommend them for any job big or small!!! Open

Tony and his crew did an awesome job on our home! We had all 13 windows and 3 sliders replaced and couldn't be happier. I would definitely recommend them for any job big or small!!! Open

Have used Cornerstone twice. A total of 4 sliding patio doors, several stationery panels of glass, and a bathroom window, on 2 floors of our home. One sliding screen had a manufacturer defect and the office staff placed an order for a replacement to be shipped to our home. The owner Tony is great and his installers, Antonio and his crew, are the best we've ever experienced for anything done to our house. Amazing work done in a very efficient time frame. WE HIGHLY RECOMMEND CORNERSTONE! Open

I just had three windows replaced by Cornerstone.  From the first estimate to Antonio and his installation crew, the experience was seamless.  They are extremely professional and fairly priced and respected by Torrance Building Inspectors as well.  I bought noise reduction windows, and so far, the level of noise has been reduced by at least half. Open

Very professional company, and workmanship outstanding. Would recommend to my friends for repairs and or replacement of windows and doors. Open

I am so happy my neighbor referred my to Cornerstone. With a double lifetime warranty and at a fraction of the cost of another neighbor's top of the line windows, I feel like quite the savvy shopper. My favorite part of the process was having Antonio and his crew show up promptly and each greet me professionally with a friendly smile, their name, and a handshake. They worked extremely well as a team and not only were tidy, got everything handled in one day, even finishing early. I would definitely recommend this company to my friends and as a local realtor, to my clients. Thank you all! Open

Cornerstone® made it simple and easy to get all of our windows replaced. They had a full crew, arrived on time, spread protective covers over everything, and handled the entire window replacement process (including sliders and screens) in a quick and professional manner. We had investigated several other firms and took the recommendations of our complex's maintenance manager and went with Cornerstone®. Based on results, it was one of the best recommendations we have ever received for any kind of home maintenance, upgrade and repair work. Mike Rounds and Nancy Miller Open

We replaced over 20 windows, a french door and a picture window in our house over three separate installations by Cornerstone.  Installation crew was always on-time, polite, careful and left no mess behind.  Maggie in the office is on top of our order and helpful.  Because of the financial impact, we needed to spread this replacement project over three years. Keeping the same installer and product were important to us and Cornerstone met our needs. Open

From the front office, Maggie and Tony, to Antonio's installation team, our experience was excellent! Antonio's crew installed our windows quickly, they were efficient, very respectful and left everything extremely clean. I have no hesitation giving this company a five star rating. Thanks for doing such an amazing job! Open

After much research and referrals from friends, I'm so glad that I went with Cornerstone! The owner Tony was professional, friendly, and thorough in explaining my options and choices. Antonio and his installation team were not only efficient and courteous, but took great care to move furniture back in place and thoroughly clean up after install. The big hit on my list was the bay window in front!! I chose that so my dogs could have a "lookout point" and they are beyond thrilled with my decision.  The windows are better than I expected.  I immediately noticed the difference in keeping the summer heat and neighborhood noise out and look fantastic as well!! This home upgrade was a smooth and efficient process. Again, I HIGHLY RECOMMEND Cornerstone! Open

I recently replaced all of my windows in my home, and utilized cornerstone's team.  Tony was prompt and provided good guidance throughout the process. His team, Antonio, and the entire work group, was great.  I ended up adding two new extremely large plate glass replacements, along with new glass front door.  I would highly recommend the entire team, Tony, the windows and overall working relationship.  Thank you for the great work. Open

We have three buildings that required multiple windows in each unit.  They knocked out about 80 windows so quickly and so professionally.  Tony worked with me on  EGRES requirements as we coordinated with the city to ensure that we were properly permitted.  The installers who worked with me daily were very conscientious, organized, and did excellent work.  I have had contractors here for large projects where it felt like a black crowd came over the properly until they left, but in all sincerity, I did look forward to seeing Tony's crew each day.  Communication was excellent, as was the workmanship.  Very happy with the job, and would highly recommend especially for large projects. Open

We had a great experience with this company. We got bids from 6 companies and decided on Cornerstone based on their price, quality of windows and our meeting with Tony (the owner). The windows are wonderful. The men who installed them (led by the wonderful Antonio) were professional and careful to take care of our home. FYI we had 17 windows, one exterior door and one slider replaced. Great product, great service. Open

Replacing the windows in your home isn't your typical run of the mill purchase. It's an investment, one that will add value to your home. We knew right away that replacing our windows was at the top of our list for home renovations, so we wanted to do the proper research before settling on a contractor. We also wanted to take it a step further and accompany new windows with shutters. Granted there are a lot of businesses who offer great deals and have proven to do an amazing job. Comparatively looking at Cornerstone (when it came to windows) we knew right away that Tony had both the experience and the competitive pricing that placed them at the top of our list. When we discovered that they also provide shutters (one of the few Windows contractors who do), and laid out pricing for BOTH, the combined pricing was in fact better on our pockets, and left us with the peace of mind knowing that we would be dealing with just one single contractor for both needs. Cornerstone was simply the best choice for us. Tony brought us through the entire process, offering excellent advice when comparing windows and shutters and helped us come up with a solution which worked best - based on whichever window line we decided on. Thankfully we made the right choice going with Simonton. His staff are some of the most professional we've ever dealt with. They were amazingly fast and care about the little details. Once they were done, we honestly couldn't tell that the crew had been working all day inside and outside of our home. The finished job looks stunning and added so much curb appeal to our home. All of our neighbors have commented and said how much they love the new windows. Owning an older home with 20+ year old windows can turn your home into an oven on hot days, which can be very uncomfortable considering we don't have central air. The quality of these windows have insulated our home so well, that we're reconsidering whether we even need central air. We couldn't recommend a better contractor for windows installation. If you're considering both windows AND shutters, then there is simply no better option considering our amazing experience with Tony and his team. We can't thank you enough!!! Open

I'm not a window expert, but Cornerstone did a great job all the way from the quote, to clarity with scheduling, and professional installation. Every day that I look out my nice patio doors, I am reminded of the positive experience at Cornerstone. Thanks, guys! Open

Rockler Open