The timber window
Wood windows has a long life span, if maintained correctly, and does in general require regular maintenance. Timber is by far the most popular window material in modern time until the us of uPVC and composite windows took over. Timber has great insulating properties and is easy to work with.
Early frame and sash windows were not very airtight and only had a single sheet of glass.
Unfortunately timber also responds to the air humidity and shrinks and swells according to the weather changes.
Rot in the lower frame corners are the most usual reason for wood windows to need replacing.
Improved wood windows
Today double glazing is standard with triple glazing being an increasingly popular choice for self-builders trying to minimise energy bills in their dream home.
Before launching proper alu clad windows a small aluminium drip was added to guide water away form the wooden sash and thereby extend the lifespan of the wooden windows.