Cornerstone Windows & Patio Doors

Replacement Experts

Cornerstone Windows features a wide selection of replacement windows and patio doors from the industry’s premier companies Reduce energy bills & improve security Cut outside noise One - Day Installation No Dry Wall or Stucco Damage Contact Us Torrance Showroom

New Safety Practices

Cornerstone Windows and Doors is open to service your window and door replacement needs!

Please call or email to schedule a free in-home estimate, or if you have questions.

To protect customers and employees, we’re practicing all health and safety precautions required by the CDC and local health departments, including: employee temperature monitoring, social distancing, masks, gloves and sanitizing practices.

In a concerted effort to keep our office staff and customers healthy, Cornerstone is no longer allowing for non-scheduled showroom visits. Only customers with SCHEDULED and CONFIRMED appointments will be permitted in our showroom. All Covid-19 safety protocols must be followed before entering. Masks required. Please call us to schedule an appointment. (310) 325-4700

Thank you for your cooperation.

Stay healthy. Stay Safe.
Tony Szik-Owner, Cornerstone Windows

Your home is a family’s biggest financial investment. Replacement windows, entry doors, and sliding and swinging glass patio doors are proven and cost effective way to improve your home’s value, beauty, energy efficiency, security and reduce outside noise.

Cornerstone Windows features a wide selection of replacement windows, patio doors, and entry doors from the industry’s premier companies, including Milgard, Simonton, and Masonite. All products are expertly installed and include exceptional warranties, including a double lifetime warranty. Please ask for more details.

Cornerstone has been in business since 1998 and  developed an installation system allowing our installers to complete projects with no drywall or stucco damage. Additionally, most jobs are completed in one day. Protecting your home and furniture during the entire installation process is always a priority.

Cornerstone offers a free, in-home, no pressure consultation. 

We are proud to be voted a South Bay Favorite for Windows & Doors in 2021 and 2020 by readers of the Daily Breeze!

Cornerstone Windows & Patio Doors - 2021 Daily Breeze South Bay's Favorite Window Door Company
Cornerstone Windows & Patio Doors - 2020 Daily Breeze South Bay's Favorite Window Door Company