How It Works

Three states of the same window.

Restoration is not a single operation. It is a sequence of decisions about what to keep, what to remove, and what to upgrade — made opening by opening, component by component.

A removed sash showing advanced decay along the bottom rail

Step 01 — The Original Frame

What twenty years of weather does to a wood window

Failure rarely starts at the glass. It starts where water sits: the bottom rail, the sill, the joint where the finish film cracked three winters ago. By the time fogging appears, the assembly has usually been telling you something for a while.

Wood decay: Sustained moisture in the rail and sill
Fogged glass: Perimeter seal fatigue in the insulated unit
Failed glazing: Shrunken bedding compound and split bead
Air leaks: Compressed weatherstrip, out-of-adjustment hardware
Single pane: No sealed cavity, no coating, no argon

Section Detail

What changes inside the frame.

A cutaway of the same Pella unit at three stages: the original single-pane interior, the renovated frame with new VG fir or hemlock and a Low-E insulated glass unit, and the finished assembly.

Three-panel cutaway diagram: old Pella frame with single pane, renovated frame with new treated wood and Low-E insulated glass unit, and the finished restored window — Rotted stock is cut back and replaced with condition-treated vertical-grain fir or hemlock milled to the original profile. The removable single-pane interior comes out and a Low-E insulated glass unit goes in — same sightlines, better performance.

The full ten-step process

From the first moisture reading to the final hardware adjustment, every stage is documented and repeatable.

Read the process →