House extension flat roof
Many house extensions incorporate a flat roof but these are usually only limited to the ground floor
element of the extension as the Planning Department usually resist a two storey house extension with a flat roof. A
house extension flat roof can also be found on dormer windows which can range from modest small flat roof dormer
window extensions to big box dormers taking up the entire roof slope.
House extensions flat roofs used to be dismissed as a poor mans extension due to their
cheapness in cost and external appearance. They also had a reputation for leaking soon after construction. However,
many house extension flat roofs are back in fashion given the improved materials for the roof covering from single
membranes, polymer modified felts, liquid applied coverings such as modified grp etc. Provided liquid applied hot
tar is removed from the flat roof covering process, a lot of the problems seem to have been removed.
There is also a demand for a more modern or contemporary feel for the house extension so many flat roofed
designed extensions fit this bill very well. Many house extension flat roofs incorporate a central glazed cupola or
lantern roof design often called orangeys.
The house extension flat roof also helps to keep the built form or bulk of the extension down to minimal
measures so they can be very useful when close to a boundary or neighbours window for example in order to overcome
a planning objection that would have been relevant for a taller pitched roof house extension.
When a house flat roof extension is used well and incorporates some design detailing for the
eaves or verges for example, they can be very well integrated into the main house and it external appearance. A
house extension flat roof built poorly with little thought to the design detailing can become an eyesore especially
if they attach to an existing pitched roof as the fascia board level is usually much higher on flat roofed
extension than for a pitched roof and often it is this abutment or junction that can let down a flat roofed house