It is true to say that double glazed panels can be supplied in virtually any size (we have recently installed one that was 5.1 metres x 2.8 metres), but there are certain parameters that will keep both costs and delivery times down. A standard sheet of glass is 6 metres x 2.44 metres; therefore if at least one of the dimensions can be kept below 2.44 metres a standard sheet can be used. If both dimensions are above 2.44 metres then the cost can double.
If you are planning to install large and oversized glass then a crane operation will almost certainly be required. As an indication of weight; glass weighs 2.5 kg per millimetre of glass thickness per square metre. A double glazed panel will typically be made from a 10mm layer of toughened glass and a 6mm layer; therefore the glass thickness is 16mm x 2.5kg = 40kg per square metre. For roof glass we set a limit of 100kg for a manual lift (2.5 square metres) and for vertical panels the limit is 150kg (3.75 square metres). These figures are for guideline only and will depend on access and other considerations.