Planning Permission

A planning application for installing a kitchen or bathroom is generally not required unless it is part of a house extension.

However, if your property is a listed building you should consult the Local Planning Authority.

Greener Homes

Pay attention to the appliances and fittings. Look for A-rated (energy efficient) kitchen appliances. Also look for aerated taps, which reduce water use.

If mains gas is available, use it for cooking as well as heating. If it’s not, consider an electric induction hob, which saves energy over a conventional electric or halogen hob.

If you are undertaking a bathroom renovation, think about the amount of water you are going to consume. You can usefully reduce this by buying low flush toilets, low flow showers and basin taps, and a smaller capacity bath.

(Advice kindly provided by the Federation of Master Builders)

Building Regulations

Work to refit a kitchen or bathroom with new units and fittings does not generally require building regulations approval, although drainage or electrical works that form part of the refit may require approval under the building regulations.

If a bathroom or kitchen is to be provided in a room where there wasn’t one before, building regulations approval is likely to be required to ensure that the room will have adequate ventilation and drainage, and meet requirements in respect of structural stability, electrical and fire safety.

Further information

The following pages give an indication of some of the elements normally required to satisfy the requirements of the Regulations for kitchens and bathrooms:

The following common work section gives an indication of other elements normally required to satisfy the requirements of the Regulations for kitchens and bathrooms:

Building Control may ask for further details and works depending on the building and circumstances.

Impact on accessibility of ground floor WCs

Any dwelling unit that has been constructed after 1999 will have a ground floor WC installed which has been designed to cater for any visiting wheelchair users.

During any re-fitting this WC should not be removed and the accessibility of the WC should not be made any worse as it would then be inadequate for future wheelchair users.

For these reasons, a Building Regulations application may be required if any alteration is to take place to an existing ground floor WC.

Suitability of existing floor structures

If the use of a room is changed and could result in the load (weight) on the floor structure changing significantly work to strengthen the floor may be necessary.

For example, if a new bathroom suite is installed in a room where the floor structure is constructed of timber joists and boards, there is a significant risk of the floor being overloaded from the bath once it is full of water and in use.  Therefore, work may be needed to strengthen such a floor.

A structural engineer or surveyor can assess the floor and determine this for you.  If the floor does need to be strengthened they can produce the paperwork Building Control will require before you commence the work.

Need for additional ventilation

Each new room in a house should have adequate ventilation for general health reasons. The type of room will determine how much ventilation is required.

When inserting a new internal wall care should be taken not to make any other matters, such as ventilation worse.  If a new room is being created as a result of  the addition of an internal wall then care should also be taken to ensure that the existing room is ventilated adequately. The general rules for ventilating a room are:

Purge – this is achieved by opening the window. The opening should have a typical area of at least 1/20th of the floor area of the room served, unless it is a bathroom which can be any openable size.

Whole Building – this is also known as trickle ventilation which can be
incorporated in to the head of the window framework, or by some other means.
The area varies on the type of room:

  • Bathroom – 4000mm²
  • All other rooms – 8000mm²

Both of these forms of ventilation are normally required, however alternative approaches to ventilation may also be acceptable, subject to agreement with the Building Control Body.

Mechanical extract fans

Any new kitchen, utility room, bath/shower room or WC with no openable window should be provided with a mechanical extract fan to reduce condensation and remove smells.  The necessary performance of these extract fans is normally measured in litres per second (l/s) as follows:

  • Kitchen – 30l/s if placed over the hob and 60lt/s if place elsewhere.
  • Utility room – 30l/s
  • Bath/shower – 15l/s with a 15 minute overrun (after the light is switched out) if there is no openable window.
  • WC – 6l/s with overrun.

Alternative rates may be applicable if the ventilation is running continuously.


This is an introductory guide and is not a definitive source of legal information. Read the full disclaimer here.

This guidance relates to the planning regime for England. Policy in Wales may differ. If in doubt contact your Local Planning Authority.