As you can see from the pictures this was more than just a loft conversion, the gable was built creating two new rooms on the first floor and a very large bedroom with full en-suite on the second floor (loft).
Below are links to the pages showing the different stages.
Loft Conversion Advice Links
We fitted three large top opening Velux windows in the roof and one normal window in the gable which would also serves as a fire escape. Note also the air vents on the ridge tiles, these prevent moisture building up and wet rot setting in, and the soffit boards are also vented. Note there must be a 50mm ventilation gap between insulation and roof tiles.