412.431.4224  |  Send Message

title icon

OSI Window & Door System

OSI Window & Door System

The most experienced windows sales staff in the Pittsburgh area with a deep Historical Perspective and Sensitivity.

Allegheny Millwork offers a wide selection of quality and style for the windows in your home. Some of our products can be used on both residential and commercial applications. In both cases, we can customize sills, casings and colors.

OSI has partnered with JELD-WEN Windows & Doors

JELD-WEN recommends the OSI® QUAD® Window Installation System for installation of their windows and doors.

For more information contact our Window Department 412-431-4224.

Visit our on-site Showroom so you can better compare solutions and get a true representation of size and color as well as discuss options.

Schedule an Appointment