So, you want to convert your loft!

Other considerations are fire doors, these would need to be fitted at the entrance to every habitable room on all levels, these need to be rated to FD30S, certain doors may be able to be upgraded, but in most cases it is most cost-effective to replace the doors with fire doors, in addition to the fire doors you will require smoke detectors on all levels of the stairwell, these must be 240 V hardwired with battery backup and they must be interlinked so if one is activated they all go off in simultaneously .

First story windows need to be fire egress windows, this means that they must be 450 mm x 450 mm height and width once open, so remember to consider any loss of space from the cantilever system for opening and closing the window, this is for people to be able to be rescued by the emergency services in the event of a fire.

You must have at least 2500mm in height from the existing internal ridge line to the top of the rafters to allow for the increase in height of the floor (which could be 200 to 300 mm, due to structural changes required) if ridge steel is required that would also drop the roof height by 200 to 300 mm, so deduct 600mm from the rafter to ridge height and you will have an indication of the least amount of height and space you are able to create.

Finally, stairs!, you will need to consider how you are going to access this lovely new space. So if you existing layout does not present an obvious solution you may need to adjust the current layout to accommodate them.