This is a straightforward and economical response to the simple requirement for an extra - proper - bedroom with shower room.
Although the footprint of this house is in the shape of the traditional Victorian L, these clients have restricted themselves to the main roof space and specified a room for an office/spare bedroom, with shower room.
At the front of the house are a couple of Velux roof lights which are barely noticeable from the front but provide excellent natural light for the desk, The dormer extension at the rear is full width and maximises the space of the front main apex loft area.The result is a well-sized bedroom at the back with a vertical window or French doors with juliette balcony. The shower room fits nicely into the front roof sloping ceiling, where the velux roof window provides light and head room.
RH box dormer - example 1
RH box dormer - example 2