310-325-4700
License #565275

Replacement Windows

Cornerstone Windows and Patio Doors

Window Replacement Experts

Window & Patio Door Experts

Cornerstone Windows has been servicing South Bay homes for 20 years, specializing in retrofitting windows into existing frames with no dry wall or stucco damage. Most projects take only one day. We do not use subcontractors and are licensed, bonded and insured.
New windows and patio doors also offer noise reduction, increased security, and improved insulation. Dual pane, energy efficient, low-e glass reduces ultra violet rays from entering your home, reducing heat in the summer, and adding extra insulation in the winter.
Cornerstone Windows is proud to install vinyl and fiberglass replacement windows and patio doors from the industry’s premier suppliers, Milgard and Simonton.
Contact UsMeet The TeamEntry Doors
Milgard Windows and Doors logo
Simonton Windows Doors logo - Cornerstone Windows and Patio Doors

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.

Stay healthy. Stay Safe.

Tony Szik-Owner, Cornerstone Windows