So; our windows are single-glazed wood frames affairs, with two sash windows, the rest with opening panes. They aren't very heat efficient, and don't block out noise very well. So we'd like to replace them with double glazed units.
What are our options? Adapt existing frames (swap inner frames for DG units), or change the whole lot? We'd prefer wood frames; UPVC won't be going in our home.
How easy would it be to DIY some frames?