Very cool idea - I guess it's a type of storm windows?
Merton House / Thomas Winwood Architecture + Kontista+Co © Emily Bartlett
Cabin on a 0.7-square-mile island 20 miles off the Maine coast, by Alex Scott Porter Design
Rejas Corredizas para esta ventana. Más
Pella Impervia Fiberglass Sliding Windows | Pella.com
If I had it my way, my whole house would be made of these doors/windows/walls.
A Cluster of Cabins in a Former Quarry Makes a Simple Vacation Escape