Heat loss through windows

If your windows are draughty, letting in excessive amounts of air around the frames, draughtproofing is likely to be more important than upgrading the glazing. If you get new windows, they should be installed to fit well, but if you’re putting new glass in old windows, draughtproofing is an added cost.

If you replace the windows and not just the glass, think about what you want users to be able to do with them. Should they be able to open them all the way, given that they might then leave them open? If you want users to be able to open the windows, you need to make sure they can reach them easily without standing on a chair and that they have arthritis-friendly hardware. It’s less draughty if the windows open at the top, not the bottom, making people more comfortable in the space.