I know what you might be thinking...surely this should have been my very first post? After explaining all the variables, all the benefits and all the reasons to have them installed, why am I now going back to basics and going over what they actually are?

Mainly because whilst they may not be a new product, they are growing immeasurably in popularity and are being installed more and more frequently into extensions and new buildings as an alternative to French doors. However, the only people who seem to know about them are builders/architects/tradespeople, which to us is a big shame. We want YOU the consumer to be as knowledgeable as your architect, so that you can make a considered and informed decision.