Why lofts are different
Adding a storey changes the fire strategy of the entire house. Approved Document B treats a three-storey home very differently from a two-storey one — escape routes, doors, alarms and protection all change.
Structure
New floors usually need steel beams, and the existing roof structure almost always needs alterations. Engineer's calculations and details are inspected, and bearing points matter.
Insulation, ventilation, escape
U-values for new roof slopes, ventilation to prevent condensation, and a protected stair from the loft to final exit are all checked. None of these are optional.
Frequently asked
Yes — even where planning is permitted development, Building Regulations apply.