Why Cornerstone Windows & Patio Doors
Is Different

All we do is replace windows & doors!
Installing high-quality replacement windows and patio doors improves your home’s beauty, minimize outside noise, and reduce heating and air conditioning bills.
Here’s why Cornerstone is different:
- Serving the South Bay since 1999
- Owner, Tony Szik, has over 40 years of contracting experience
- Fully licensed, bonded, and insured
- NO subcontractors – only Cornerstone employees
- Products are purchased directly from the manufacturer – no middlemen
- All windows & doors are custom manufactured to fit your home
- Cornerstone practices all health and safety precautions required by the CDC and local health departments.
We offer a large selection of high-performance products in the following categories:
- Vinyl Windows
- Fiberglass Windows
- Aluminum Windows
- Patio Doors – swinging & sliding
- Entry Doors
- French Doors
Our Commitment
Our commitment spans from everything to the value of our products to the craftsmanship of installation.
Transform your home with new windows! Call (310) 325-4700 or contact us today for a FREE in-home estimate.
