Practice guidance showing how to comply with the Building Regulations is contained in ‘approved documents’ issued by the Government. As far as your build is concerned, these are a bible and legally enforceable. The full documents can be accessed on the Government website.
A – Structure.
B – Fire Safety.
C – Site preparation and resistance to moisture.
D – Toxic substances.
E – Resistance to the passage of sound.
F – Ventilation and condensation.
G – Hygiene.
H – Drainage and waste disposal.
J – Heat producing appliances and fuel storage systems.
K- Stairs , ramps and guards.
L – Conservation of fuel and power.
M – Access and facilities for disabled people.
N – Glazing.
P – Electrical safety.
Of these, documents A, B, F, K,L, N and P will definitely apply to loft conversions.