A hip roof slopes on all sides, the side wall is square shape and finishes at eaves height. A roof with a gable wall construction will slope on two sides, the side wall is triangle shape and finishes at ridge height.
A loft conversion with an existing gable wall will require less work than a hipped roof conversion. This will effect the overall cost of the conversion. There are three main methods of construction to choose from to match the existing character of the property.