Checking the Feasibility of Conversion

There are three key factors to consider when contemplating a loft conversion: roof construction, headroom and access.

Roof Construction

Traditionally, pitched (sloping) roofs were built on site, using rafters supported by high-level horizontal beams called purlins. The resulting framework leaves the central space unobstructed and makes it fairly easy to incorporate window openings in the roof. Many modern roofs are built with prefabricated trusses, which have lower, horizontal timber braces to give them strength. Unfortunately, these braces make it difficult to move around the loft space. Conversion may be possible, but it will be more complicated and the extra expense may not be justified.

Headroom

In order to move about the loft easily, you need a minimum height of about 2 m (6 ft 5 in). Measure the floor area that offers this headroom to check whether it will be adequate. Consider whether you need one or more dormer windows. Lower-ceilinged areas around the edge of the room can be used for storage and for some furniture. A desk, for example, can be tucked against a wall that is less than 1 m (3 ft) high, as long as the pitch of the roof allows you to sit and stand up comfortably.

There must be adequate headroom above the stairs as you enter the new room. To achieve this you may either have to position the stairs to enter the room under the highest point of the roof - which would use up valuable floor space - or build up the wall and raise the roof over the stairs.

Access

Decide where to locate the stairs leading up to the new room. In a single-storey house, space for the new staircase will have to be taken from the hall or one of the rooms. In a two-storey property, the usual location is directly above the existing stairs.