From 25th June 2013 it is a statutory requirement to include a "Design and Access Statement" with planning applications for:
The Council, in conjunction with the other Local Planning Authorities in Hampshire and the Isle of Wight, has produced the following guidance on preparing Design and Access Statements which can be downloaded.
1. Design and Access Statements - Guidance for Applicants and Agents
Further information on this is given in Department for Communities and Local Government (DCLG) Circular 01/2006: "Guidance on Changes to the Development Control System".