The Government Department responsible for Building Regulations is the Building Regulations Division of the Department for Communities and Local Government (DCLG).

The following links will take you directly to their website.

Circular 02/2010: the Building Act 1984, Building Regulations 2000, Amendments relating to Approved Documents B and L 2006 editions

Building Regulations Approved Document and Associated Guidance (this links to the 'Planning Portal' website, the UK Government's online planning and building regulations resource)