Creating a new basement will usually require planning permission, particularly if it affects the external appearance of the property. For example, installing a lightwell to bring natural light into the basement may be subject to stricter design rules if it is visible from the street, especially at the front of the property, compared to those at the rear or side.

Because basement construction involves significant excavation and structural work, permission is often necessary. It’s recommended that you consult your local planning authority early on to understand what is likely to be considered acceptable before submitting a planning application. Building regulations will also apply to a new or conversion of a basement.

Read further guidance on basements.

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

The principal elevation is the most visible or prominent side of a structure, typically facing a street or public area. While often considered the 'front' of the building, it may not always contain the main entrance. There can only be one principal elevation of a house.

Following a grant of planning permission, it may be necessary to make amendments to the proposals that were originally approved. A non-material amendment may be applied for to approve a minor change to the planning permission which does not breach any conditions originally placed on the consent.

There is no statutory definition for ‘non-material’ as it can vary on a case-by-case basis. In general, if the change will increase the size, change the appearance of a development or have a large impact on other considerations then it will not be considered non-material.

Read more about this non-material amendment applications.

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Yes, but this type of conversion will require full planning permission. This is because you’d be changing the use of the ground floor from residential to commercial (typically to a use class such as E), while the upper floor would remain as a residential flat (Class C3). The change of use triggers the need for planning approval.  

Find out more about change of use

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