End-of-terrace or semi detached properties will often have a roof sloping on the side and will need what is none as a hip to gable conversion, extending the roof to the side to a gable end rather than the pitched hip end roof shape, then added a dormer extension to the rear, normally carried out via permitted development allowances on house and planning permission for flats
Velux is the brand that has become synonymous with roof lights. They offer a huge range of different designs and finishes.
Velux roof window conversions are often carried out on larger loft spaces where there is no real need for a dormer extension for example to create extra space, as there is already large amount natural space in the loft. Or if the customer doesn’t really need a great deal of extra space but is looking for a smaller conversion with an extra bedroom & possibly a shower room suite, a few Velux windows are added front a rear to add light and character to the project
Roof terrace are a fantastic addition if possible. It is not always appreciated how spectacular a difference a roof terrace can make, often added to flats and maisonettes for that missing outside space.
They are not always possible as they need planning permission and some council are not amenable to them, it really depends on the council and their planning policy