Replacement of this is moving towards the top of the home improvement list if Finances permit. It's an Everest unit and well past its best. Probably dates from when the house was built in 1970! Dimensions approx 7ft x 14ft.
bi folds would look great in that space, ive just had some fitted in my kitchen , really open the space up.
I am sure when you seek quotes, the question of double and triple glazing will be raised. Triple glazing provides benefits for better sound proofing and much reduced heat loss BUT it will you not get any benefit from solar radiation. The article I read, came to the conclusion, that if you have a south facing well lit opening, double glazing would be better but if you have a north or east facing opening, triple glazing would be better. A word of caution, a triple glazed door that size will present structural issues as it will be a lot heavier than double glazing. Andy
Bi fold doors or 3 pane sliding patios, as said 100% must be aluminium, white, black and anthracite grey are standard colours, they will all be the same price, dont get conned that grey cost extra.I use Smart visofold 1000 bi folds and can vouch for there quality, glass just go for "A Energy Rated" toughened 28mm units, if south facing then consider pilkington super grey glass (tinted and solar reflective). cost wise budget £1000 per panel, i usually sell at £750 per panel fitted. If you require a level threshold, the old indoor outdoor thing, then those type of thresholds are not weather rated so be careful.
