Dormer Extension Pitched Roof

A vertical frame supports the planes to form a triangular section below the roofline.

Dormer extension pitched roof.

Dormer dormers contain a window that projects vertically from a traditional pitched roof creating an extended window in the roof. Mansard roofs are similar to hip roofs except that each side has two parts. This type of roof is most popular in loft conversions providing an easy way of expanding the space and natural light in the converted loft room. While the extension features a modern steel structure and a large amount of glazing the roof features stone slates to provide a sympathetic nod to the original cottage.

A gable fronted dormer is the most common type of dormer window and traditionally has a simple pitched roof sloping to two sides. Fit into a steeply pitched mansard roof this shed dormer sits almost flush with the surrounding slates. Hipped dormers maintain consistency with hipped roofs and add visual contrast to gable roofs. The roof structure is altered at the sides or rear of the house to add a large flat roofed box dormer.

Dormers are commonly used to increase the usable space in a loft and to create window openings in a roof plane. A dormer is a roofed structure often containing a window that projects vertically beyond the plane of a pitched roof. Dormer loft conversions are the most popular option as they are the easiest way to add light and an increased amount of roof space with full headroom. When the dormer gable is inspired by a classical pediment the pitch can be lower than the house roof down to about 5 in 12.

Rather than a two sided gable a roof dormer has sloped roof sheathing and roofing material on all three sides. Along the level line and using a square to draw a perpendicular line up to the roof edge of the board. A shed dormer has a sloped single flat plane roof in the same direction of the roofline but at a shallower angle. Homeowners charlie and rose thomas worked with architectural designer charlie luxton to design the contemporary extension that replaced an aging conservatory.

Make a rafter cutting jig by measuring 12 in. Similarly when the facade is short the dormers can be short. On many houses you can ignore the base of the house and focus simply on how well. If the slope of your dormer roof is the same as your old roof hold a scrap of plywood against the old roof boards and draw a level line on it.

The point at which the three sloping sides join is over the center of the dormer rather than at its front as with a gable dormer.