When Do You Need Building Control

You need Building Control approval whenever construction, alteration or improvement work affects the structure, safety, drainage, energy efficiency or accessibility of a building. In the UK, Building Regulations are separate from planning permission and apply to most building projects regardless of whether planning consent is required. The purpose is to ensure that building work is safe, legal and up to standard—and to protect both property owners and future occupants.

Projects That Require Building Control

Building Control is required for a wide range of domestic and commercial works. This includes:

New buildings such as houses, flats or commercial units
Extensions to existing buildings, including single-storey rear extensions, conservatories (in some cases), and garage additions
Loft conversions where the space is turned into habitable rooms
Garage conversions involving changes to structure, insulation or use
Removing internal walls, especially if load-bearing
Installing new windows or doors, particularly when enlarging openings
Roof works including replacement of structural roof elements or re-roofing large sections
Drainage alterations such as adding toilets, sinks or new sewer connections
Electrical and heating installations in kitchens, bathrooms and other regulated areas
Fire safety works, including fitting fire doors or creating protected staircases
Insulation upgrades to walls, floors or roofs
Basement conversions, underpinning or major structural changes

These examples are all considered “notifiable” under Building Regulations and require either a Full Plans application or a Building Notice.

Projects That Usually Don’t Need Building Control

Some minor and cosmetic works are exempt. These include:

Painting and decorating
Fitting kitchens or bathrooms without moving plumbing or electrics
Replacing like-for-like doors or windows
Laying flooring, tiling or installing carpets
Putting up non-loadbearing internal partitions that don’t affect fire escape routes

Detached buildings such as sheds, greenhouses or garages under 15 square metres, built more than one metre from any boundary and not used for sleeping, are often exempt too. However, if they contain electrics, plumbing or insulation, Building Control may still be required.

Why It’s Important

Getting Building Control approval ensures that your building work complies with safety and performance standards set out in law. Without it, your project could pose serious risks—from fire hazards and structural instability to poor ventilation or water leaks. It can also cause problems when selling or insuring the property. A lack of Building Control sign-off often results in enforcement action or the need for costly retrospective inspections and remedial works.

When in Doubt, Always Check

If you're unsure whether Building Control applies, contact your local authority or consult an Approved Inspector. Even simple works can have legal implications, particularly in flats, listed buildings or homes in conservation areas. It is always safer to confirm than to assume, as failing to comply can delay a sale or create liability.

Conclusion

You need Building Control whenever your work affects the structure, safety, drainage or energy performance of a building. From extensions and conversions to structural alterations and electrical works, Building Regulations apply to most building projects in the UK. Understanding when to seek approval protects your property, your investment and your peace of mind.