We are OPEN for business! Call today to a schedule a consultation!
We've changed our name! To better describe our commitment to superior service, SI Windows - Phoenix is now


Infinity Logo windows

Featuring Infinity from Marvin Windows & Doors

Google’s #1 Rated Window & Door Company in Phoenix

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Our Ultrex® fiberglass delivers lasting performance

  • Expands 87% less than vinyl – resists expanding and contracting in any climate
  • 8 times stronger than vinyl – protects the integrity of your home
  • Resistant to leaks, seal failures and stress cracks – all things that can affect energy efficiency


Acclaimed design that withstands the test of time

  • Ultrex’s strength delivers narrow window and door profiles for expanded views and more daylight
  • Our proprietary acrylic finish is fade-resistant and virtually maintenance-free
  • We offer a complete collection of styles, features and options to complement any home
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The benchmark for customer service and satisfaction

  • Limited Lifetime Warranty for as long as you own your home
  • An experience that is designed to give you assurance at every step of the way
  • Our core value: Do the Right Thing

Our Process

capstone replacement windows in scottsdale az

Schedule Your Consultation

Create beautiful views for your home while protecting your family against the harsh climate. Reduce heat, noise, and dust to improve privacy and comfort. Capstone Windows & Doors uses only the finest, superior, and high-end window replacement products for your home. You can rest assured that our installers are diligent, courteous, and professional and are keen about dust and mess containment. We offer replacement windows and doors in: Scottsdale, Phoenix, and Gilbert, AZ. Call us today!

To schedule a consultation, call us (480) 800-8444 or use the form below.

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Open Hours

Monday – Friday
8am to 5pm

Saturday and Sunday
by appointment only

Showroom open by appointment


3837 E Wier Ave, Ste 4 Phoenix, AZ 85040