Just that really www.mhjoineryproducts.plc.uk/about.php
I've just Googled them and am awaiting a call back from their local person.
I know it's frowned upon but I really would like to replace my elderly sash windows with something that looks the same, is wooden but is more practical in terms of function and security. Conservation are a bit stroppy about the idea and would rather I refurb and secondary glaze. The windows have been refurbed by the previous owners. Secondary glazing would look rubbish on the windows as 4 of them are large bays. Would I have to get planning permission?