The local authority has a general duty to enforce the Building Regulations in its area and will do so by informal means wherever possible.
Building Regulations can be contravened by not following the building control procedures set out for handling your building work and also by carrying out building work which does not comply with the technical requirements contained in the Building Regulations. This will come to light during the inspections carried out by the building control service.
Where an approved inspector is providing the building control service, the responsibility for checking that the Regulations are complied with will lie with that inspector. They will mainly do this by advising you, however, they do not have enforcement powers. In a situation where they consider your building work does not comply with the Regulations, they will not issue you with a final certificate and will cancel the initial notice by notifying your local authority.
If no other approved inspector takes on the work, the building control service will automatically be taken on by your local authority. From this point on your local authority will also have enforcement powers to require you to alter your work, if they consider this necessary.
If a person carrying out building work contravenes the Building Regulations, the local authority or another person may decide to take them to the magistrates' court where they could be fined for the contravention, and a further daily fine for each day the contravention continues after conviction.
This action (under section 35 of the Building Act 1984) will usually be taken against the builder or main contractor and proceedings should be taken within six months of the offence. Alternatively, or in addition, the local authority may (under section 36 of the Act) serve an enforcement notice on the owner requiring them to alter or remove work which contravenes the regulations. If the owner does not comply with the notice the local authority has the power to undertake the work itself and recover the costs from the owner.
You can't be served with a section 36 enforcement notice more than 12 months (or 24 months for certain offences) after the date of completion of the building work, although this does not affect a local authority's (or any other person's) right to apply to the courts for an injunction for the same purpose. A local authority also can't take enforcement action under sections 35 and 36 if the work which you have carried out is in accordance with your plans which the authority approved or failed to reject within the statutory time of five weeks (or two months with your agreement) from deposit of the plans.