If you are intending to carry out a building project you will need to know if the Building Regulations apply and if the Local Authority need to get involved.
As there are so many different types of building works that can be undertaken, I would strongly suggest that you read the following explanatory booklet:
Building Regulations Explanatory Booklet
This should, hopefully, answer any queries you may have but if you require any further advice then please do not hesitate to contact me and I will try to help.