One of my neighbours is quite well known around here for his parsimonious attitude to life and parting with his cash.  He will never engage the services of a professional company if he can get a job done himself.  At times, the job is too valuable for this fool hardy and mean attitude.  Windows and doors are not the sort of thing you can easily make now.  In the old days, of course you just dug the old putty round each side of the pane of glass.  Carefully removing the single pane, you then offered up the new pane and carefully pinned it in with as few pins as you could get away with.  Then once satisfied it sat true, you started the puttying in.  After that came the repainting of the framewor.  These days though the upvc and other composite materials make it impossible to build your own window.  It’s virtually impossible to make a triple glazed window or door without a huge back up team.