The requirement for Building Control approval is triggered by the nature of the work being carried out rather than the size of the project. Some very significant-looking work, such as replacing kitchen units, does not require Building Control, while some small structural alterations do. The key is whether the work falls within the scope of the Building Regulations.

The Principal Categories of Notifiable Work

Building Control approval is required for all work involving the construction of a new building or the extension of an existing one. This includes house extensions, garden rooms with habitable use, garage conversions to living accommodation, and new detached structures used for habitable purposes. Structural alterations, including removing or altering load-bearing walls, inserting new structural beams, and any work that affects the building's structural stability, require Building Control.

Loft conversions creating habitable accommodation require Building Control because they involve both structural work and compliance with fire safety, thermal, and staircase regulations. New or replacement roofing where the structure is altered or the thermal performance changed requires approval. New plumbing involving drainage connections, new electrical circuits and consumer units, and new heating system installations all fall within the scope of the regulations.

Exempt Work

Not all building work is subject to the regulations. Schedule 2 of the Building Regulations 2010 sets out exempt classes of work, including most small detached buildings of under 30 square metres used for incidental purposes, porches up to 30 square metres, and some alterations to conservatories. Routine maintenance, repairs, and redecoration are not building work within the regulations and do not require approval.

Self-Certification Through Competent Persons Schemes

Many types of regulated work can be carried out and self-certified by contractors registered with approved Competent Persons Schemes, without a separate Building Control application. Gas appliance installation under Gas Safe, replacement windows and doors under FENSA, electrical work under NICEIC, and oil heating installation under OFTEC are among the most common examples. The scheme contractor notifies the local authority directly and issues a compliance certificate to the homeowner.

Summary

Building Control is required for structural work, new construction, extensions, loft conversions, electrical rewires, new heating systems, drainage changes, and changes of use. Exempt work includes small incidental outbuildings and routine maintenance. Competent Persons Scheme contractors self-certify eligible work. Work carried out without required approval requires regularisation or indemnity insurance to resolve.