Not all sash windows are made the same, over the years there have been many advancements not all of them are good though, for example while energy saving and functional upvc sash windows are not the high quality craftsman ship you would expect from hand made wooden sash windows.
The Good really should be the excellent as the quality of hard wood box sash windows being produced is really something to be quite proud of, for many homes these quality windows improve the value of the home as well as improving the energy saving with the new draught excluding properties of the window and the low E Glass that reduces the cold transmitting through the glass.
Along with the superb finish of hand made windows and the high class window furniture to bring you a window you'll be proud to have in your home.
The Bad has to be the original windows now replaced with UPVC it would be a real shame to degrade a property with these new plastic imitations of the true sash window.
The Ugly for many an original sash window could be a thing of beauty, although for too many homes still in London the neglected sash window has single glazing flaking pain and gaps that cause heat to escape, now that's an ugly situation in need of repair or replacement.
The photos attached are examples of custom hand made wooden sash windows.
So there you have it The Good the Bad and the Ugly of Sash Windows.