Some roof spaces are more easily converted than others and a full assessment requires professional help. But the untrained eye can often work out the basics. Go up into your loft space and take a look around.

 

Is there enough headroom at the centre under the ridge? You ideally need 8ft (2.4m) clearance, although you may find that you can still get a useful room from as little as 7ft (2.1m). A quick check with a tape measure will suffice.

 

Also try to assess whether your roof was built using trussed rafters or purlins, as the latter is much easier to convert into usable loft space.

Traditional (pre 1965) rafter and purlin roof construction

This type of roof, pre 1965, is ideal for loft conversions as it usually has a reasonably steep pitch and relatively clear spaces between the supporting framework.

Modern (post 1965) trussed rafter construction

This type of roof, used widely in houses in Britain since 1965, usually has a shallow pitch and more struts. As a result they are more difficult to convert. Look out for thin sections of wood (typically 75mm or 3 inches deep) and tell-tale rectangular metal plates used to join the timber together.