The Enforcement Notice will usually allow 28 days in which to rectify the building work. If you wish to contest the notice on the grounds that you believe your building work does comply with the Building Regulations, you have the following options:
If you believe that your work cannot be expected to comply with one or more of the requirements in the Building Regulations because they are too onerous or inapplicable, you have the right to apply the Council for a relaxation or dispensation of the requirement(s) in question, in order that your completed building work is considered to achieve compliance.
Your application must be made within 28 days of receiving the Enforcement Notice from the Council. If the Council refuses your application, you have a right of appeal (in England) to the Office of the Deputy Prime Minister against that refusal, providing you do so within one month of that decision.
Please bear in mind that if you take this course of action in response to an enforcement notice and you originally maintained that your work was in compliance with Building Regulations, your case is likely to be more difficult to justify.