If you're doing electrical installation work in your home or garden in England or Wales, you must follow the building regulations. It's recommended to hire an installer who is registered with a competent person scheme (a registered competent person’) who can self-certify that the work meets the required standards.

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.

National planning regulations allow certain alterations to be made to a property without requiring planning permission; these are known as permitted development rights. In some cases, local authorities may remove or restrict these rights for specific types of development that would otherwise be allowed. This is achieved through the use of Article 4 Directions, which are intended to protect the character, heritage, and appearance of designated areas.

If your local planning authority has issued an Article 4 Direction, some of your permitted development rights may no longer apply. As a result, you may need to submit a planning application for works that would not normally require one.

You can check whether an Article 4 Direction affects your property by visiting your local authority’s website.

A single storey rear extension can fall under permitted development, meaning planning permission may not be required providing it meets certain criteria.  

In terms of height, the extension must:

• Be no taller than four metres at its highest point

• Have eaves no higher than the eaves of the original house

• Not exceed the height of the original dwelling  

Read about planning permission for extensions on Planning Portal

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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 have an internal floor-to-ceiling height of no more than 3 metres, and no greater than the internal height of any existing storey within the principal part of the house.

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.