When does a replacement kitchen or bathroom need building regulations approval?

The majority of domestic like for like replacement kitchens or bathrooms won't need any form of building regulations approval, but if you're modifying the existing layout then approval may be needed.

This might be due to (from the Building Regulations):

"3(b) the provision or extension of a controlled service or fitting in or in connection with a building;
3(c) the material alteration of a building, or a controlled service or fitting;
3(d) work required by regulation 6 (requirements relating to material change of use);"

A "controlled service or fitting" means;
"A service or fitting in relation to which Part G (Sanitation, hot water safety & water efficiency), H (Drainage & Waste Disposal), J (Combustion appliances & fuel storage systems), L (Conservation of fuel & power) or P (Electrical safety) of Schedule 1 imposes a requirement."

"None of the work, or any part of it, should at any stage result in not complying with or being more unsatisfactory with a relevant requirement where previously it did."

Confused?!

So what does it mean and just how is it relevant to replacement kitchens and bathrooms?

Are you carrying out a material alteration ?

Removing load bearing walls to accommodate a new layout is a structural alteration. Design and fire resistance will be needed for the new lintel, bearings and foundations may need to be examined for suitability.

Removing doors (or non-load bearing walls) between the kitchen and other rooms, particularly to a staircase, will affect means of escape (B1). Additional precautions in other parts of the property may be needed such as escape windows, interlinked smoke and heat detection, and additional fire resistance (B3). Alternatively you may need to retain the door(s) so it is no worse than before. (Both in Part B.)

Are you carrying out a material change of use?

This classification involves the creation of a dwelling, subdivision to create more than one dwelling or flat or room for residential purposes. The installation of a second kitchen would indicate this likely use and building regulations approval would be required and possibly planning permission.

Could alterations alter the status of a building?

Other than change of use (above), a request may also be received to install a kitchen in a conservatory. Some conservatories are exempt from the requirement for a building regulations application unless the external doors are being removed or the opening widened to open it up to the main house. This removes the exemption status enjoyed by the conservatory and approval is needed.

If that happens, it reverts to an extension of the main house and thermal compliance will be difficult to achieve because of the excessive glazing. An open kitchen/dining space is a popular alteration to properties and care is needed to ensure compliance is possible.

If your building is listed in some way, for its architectural or historic interest and/or is located in a sensitive urban or rural environment (e.g. a conservation area or an area of outstanding natural beauty), then alterations may require additional consent from the planning department.

Remember the reference "Not complying with or being more unsatisfactory with a relevant requirement where previously it did"? This means that the works must not make fabric, services and fittings less compliant than they previously were – or dangerous.

For example, the provision of replacement double glazing must not worsen compliance in relation to: means of escape; air supply for combustion appliances and their flues; and ventilation for health.

Electrical installations must not worsen compliance in relation to:

• structure (depth of chases in walls, notches in floor and roof joists)
• fire safety (provision of detection systems, fire resistance of penetrations through floors and walls)
• site preparation (resistance of service penetrations to rainwater and radon)
• sound (service penetrations on party walls)
• ventilation
• thermal (use of energy efficient lighting)
• access (heights of sockets and switches)

If you're in any doubt then speak to your Local Authority building control team who can offer advice and guidance on how to comply.

Find your local authority's contact details here

Further information

Homeowners, find out much more about how the building regulations apply to your other projects such as:

• Home extensions
• Conservatories and porches
• Loft or garage conversions
• Basements
• Self build homes

Please Note: Every care was taken to ensure the information was correct at the time of publication. Any written guidance provided does not replace the user’s professional judgement. It is the responsibility of the dutyholder or person carrying out the work to ensure compliance with relevant building regulations or applicable technical standards.