Planning permission will not be require to add an en-suite provided it is within the existing building and not part of a wider project such as an extension.

 Building regulations will have to be considered when adding an en-suite as it impacts drainage, ventilation and electrics. It is recommended that you have the work completed by a member of the competent person scheme.

Find a competent person

Firewalls provide protection against fires spread which may occur to neighbouring properties. Building regulations ensure that modern homes are fitted with firewalls as well as other fire safety measures such as adequate fire escapes and alarm systems.

Older homes may not have a firewall installed in the loft, especially in homes with shared loft spaces. There is no requirement to retrospectively install a firewall, but it should be considered to improve the safety of your home and those living in it.

As an adjoining loft firewall is a party wall, you will need to talk to your neighbour to discuss the work.

Adding a storey on top of an extension will always require an application for planning permission.

If you want to add a storey on top of your house under permitted development rights, it must be on the principal part of the house.

If you want to add an additional storey on top of your house, it can be permitted development. It is only permitted development if it follows certain rules:

The current house

• Is not a building containing one or more flats, or a flat contained within such a building
• Was constructed between 1 July 1948 and 28 October 2018
• Has not already had additional storeys added to it
• Is not on Article 2(3) land or a site of special scientific interest
• Was not changed to be used as a house (from a previous non-residential use) under permitted development rights.

How many storeys can you add?

• If the house is one storey then one storey can be added
• If the house is two or more storeys then two storeys can be added

Where can the storeys be added?

• The additional storeys must be added to the principal part of the house. The principal part of the house is the main part of the house excluding any front, side or rear extension of a lower height (regardless of these being part of the original house or subsequent additions).
• Engineering operations must only include works within the existing curtilage of the house to strengthen existing walls and foundations

How high can it be?

• The house cannot exceed 18 metres in total height
• Each storey cannot add more than 3.5 metres to the total height
• If the house is not detached the total height cannot be more than 3.5 metres higher than the next highest building that the house is attached to, adjoins, or is in the same row as.
• The additional storeys must not exceed 3 metres in height or the height of any existing storey in the principal part of the house (measured internally from floor to ceiling)

What materials can be used?

The materials used must be of a similar appearance to those used in the construction of the exterior of the current house

Where can windows be placed?

Windows must not be placed in any wall or roof slope forming a side elevation of the house.

Following completion of development:

• The house must remain in use as a domestic residential property
• No visible support structures must remain on or attached to the exterior of the house
• The roof pitch of the principal part of the house must be the same as it was prior to the development.

 If any of the limits set out above are exceeded then an application for planning permission will be required. If you are unsure, you should contact your local planning authority.

Find contact details for your local planning authority.

Changing from a commercial use (use class E) to residential(use class C3) falls under permitted development rights, meaning an application for planning permission is not required.

To use the permitted development right you must meet the rules and regulations set out in legislation, this includes submitting an application for prior approval to the local planning authority. The full list of conditions is available on the government website, or our online application form will tell you whether you are eligible.

If you are not eligible for the permitted development right, you will have to submit an application for full planning permission.

Find out more about change of use

Whether you need building regulations approval depends on the type of underfloor heating (UFH) you are installing.

Electric UFH must comply with Part P for electrical safety.This work can be done by a member of the competent persons scheme who can self-certify the work.

Wet UFH must comply with Part L which focuses on the conservation of fuel and power. This will likely require building control approval.