YOUR LEGAL REQUIREMENTS
The main points in brief are:
BUILDING REGULATIONS.
Any project that
requires the alteration or installation of, drains, foundations, supporting or
load bearing members, ie steel beams or walls, require building regulations approval by LAW.
Regardless of what you call your converted roof space, a habitable room must
have the approval of the local checking authority. Failure to do this can result
in court action and a maximum fine of £6000.
The new floor must provide 30 minutes protection from a fire below it, In most older properties, the first floor ceilings are lath and plaster, or 9mm plasterboard. In these situations, a fire break has to be installed within the new floor section. The passage way, from your new bedroom, to the front or rear door, is called the "protected shaft", all doors to habitable rooms, ie, kitchen, lounge, bedrooms, off this shaft, have to be 30 minute fire resisting, or in some circumstances, existing doors can be coated with a fire resisting paint.
STAIRCASES
Staircases must be fixed and rise at an angle not exceeding 42 degrees*, handrailing and balustrading must enclose the staircase to prevent falling, and no part of that staircase must have open spaces that will allow the passage of a 100mm diameter ball. When a new staircase rises above the existing staircase, there has to be a minimum headroom clearance of 2 meters, and please remember, a pull down ladder does not apply in any shape or form.
* There is a type of staircase called a "spacesaver" or "Paddle tread" that rises at 55 degrees, you can see this type of stair by clicking "spacesaver" on the left hand links.