Open Sash

Energy Retrofit for Old Windows

restoration of old windowOpen Sash specializes in energy efficiency, weatherization, and restoration of old windows.

An Open Sash energy retrofit turns beautiful quality-made old windows into ones that are as energy efficient as a modern window—at a price that is lower than replacements.

Open Sash has developed a unique system for adding glass to the existing sash that doubles the thermal resistance of the window without changing the look or function. With the addition of modern integrated weather seals, foam insulated weight cavities, and restoration treatment, your old windows will look great and function as well as a modern window.

Our retrofit system can be used on any type of window – from historic to factory modern, single or double hung, casement or fixed. Our energy panels are custom-made to fit your needs.

In addition to being affordable, our window retrofits are also the most earth friendly, carbon neutral, and sustainable choice you can make.

Learn More About the Open Sash System

Latest News from Open Sash

New Product: Stormwindow screen combination

Posted July 7th, 2014 by Chris Pratt

Screen Storm combo

We’re now offering a new product: wooden-frame storm windows with interchangeable glass and screen panels. Instead of installing cumbersome aluminum screens every spring, just swap out our simple custom screen inserts. If you’ve been thinking about new storms or replacement screens, this a great cost-effective upgrade!



Just back from Boston’s Savin Hill!

Posted May 22nd, 2014 by Chris Pratt

Spent a week in close quarters with the crew, surviving solely on bar-room Chinese food – all for the sake of completing seven third-floor window retrofits on a lovely 1870s Queen Anne home in the Savin Hill neighborhood of Dorchester, MA.  Curved top windows presented a fun challenge.  The clients were delighted to have the modern factory-made square storms removed to reveal the original elegant design of these classic windows.  Good time all around, and a successful restoration story!