A Lean-to Conservatory normally has a mono-pitch roof which slopes back to the house wall. In some circumstances, it is possible to 'hip' one or both ends of the roof to introduce a more stylish appearance to the simple lines of the lean-to.
A lean-to style conservatory is immensely versatile - it can be built as a bay, into a corner or an alcove, and can also be 'wrapped' around an external corner of your property.