If you are thinking of ordering double-glazed windows and not sure how to go about it then the Modern UPVC Windows website has been designed for you. Just start by entering the required window size and then specify from a simple list of options. Each set of options has a pop-up window clearly explaining what they are. As you include options the on-screen graphic updates to show you exactly what it would look like. Brilliant! We are currently renovating an old single-glazed property to full double glazing including doors. This company is making it so easy. Thumbs up to them!