The height at the highest point in the roof
This dimension essentially determines the geometry
of the roof cross section and hence the available
height of the finished conversion.
Whether hipped, gabled or other
Gabled or mid terraced houses have most potential,
others mostly hipped roofs, usually require modification
sometimes very substantial modification.
Whether prefabricated truss type or cut roof with
Traditional type cut roofs with purlins tend to
be easier to work with and hence cheaper. However
prefabricated trusses can be redesigned to allow
for an attic conversion. Both require redesign
by a Structural Engineer to ensure continued Triangulation
and structural integrity when members have be
removed or altered.
Whether Conventional, timber frame or other.
Conventionally built houses are the most common
and easiest to convert. System built Timber frame
and other ‘optimized design’ types
are possible to convert but again require the
redesign of the truss and sections of the timber
frame by a Structural Engineer.
For some properties the benefits greatly outweigh
the cost but sometimes too much work and alterations
may be involved
Planning permission may not be obtained or conditions
attached to permission may restrict the possibilities
It may not be possible sometimes to achieve the
desired result without undue impact on the aesthetic
impression of the property. When a house is part
of a scheme it is usually not a possible (or indeed
prudent) to radically change its appearance.