Competent person scheme
The Competent Persons scheme was introduced by the UK Government to allow individuals and enterprises to self-certify that their work complies with building regulations as an alternative to submitting a building notice or using an approved inspector
A Competent Person must be registered with a scheme that has been approved by The Department for Communities and Local Government (DCLG). Schemes authorised by the DCLG are listed on its website at http://www.communities.gov.uk
or for more information you can look at the competent person website
To understand why you should use a Competent Person, Download the consumer booklet.