Conservatory legal rights and when you need to get planning permission

With the warmer weather arriving and homeowners eager to make the most of their gardens, many are considering extending their property with a conservatory. It is widely regarded as a more straightforward means of gaining additional space compared to a full-scale extension.

One of the principal reasons for this is that, in many cases, the process can be undertaken without the need to obtain planning permission. This is owing to the fact that conservatories can fall under the category of permitted development.

However, prior to commencing any work, it is crucial to understand precisely what is and isn't permitted within these regulations. Failing to get it right could result in significant complications further down the line.

According to Planning Portal, a joint venture between TerraQuest Solutions Limited and the Ministry of Housing, Communities and Local Government (MHCLG), adding a conservatory to a house falls under the same planning regulations as any other residential extension.

These are, as previously mentioned, known as permitted development rights. These entitle homeowners to extend their property without submitting a planning permission application, provided the work remains within specified limitations and conditions.

The portal stated: "If you want to exceed these, then it is likely that an application for householder planning permission will be required. If the work adds over 100 square metres of floor space, it may also be liable for a charge under the Community Infrastructure Levy. If you are unsure, you are advised to contact your Local Planning Authority for guidance before starting any work."

For all extensions

The specialists noted that no more than half the land surrounding the "original house" may be covered by extensions or additional structures. These must not rise higher than the uppermost point of the existing roof, nor exceed the height of the existing eaves.

Where the extension falls within two metres of the boundary, the eaves height must not surpass three metres, it added. The extension must not be built forward of the 'principal elevation' or, where it faces a highway, the 'side elevation'.

The work must not incorporate verandas, balconies or raised platforms; a microwave antenna such as a TV aerial or satellite dish; a chimney, flue or soil and vent pipe or any alteration to the roof of the existing house.

For side extensions

The specialists further clarified that, where it would stretch beyond the 'side elevation' of the original house, the extension must not surpass four metres in height, must be single storey only and must not exceed half the width of the original house.

For single-storey extensions

The experts clarified that single-storey rear extensions cannot protrude beyond the rear wall of the original property by more than four metres for a detached house, or more than three metres for any other type of house.

They added: "Where not on Article 2(3) designated land or a Site of Special Scientific Interest; and subject to 'prior approval', the limit for single-storey rear extensions is increased to eight metres if a detached house; or six metres for any other house. This requires that the relevant Local Planning Authority is informed of the proposed work via a prior approval application. Single-storey rear extensions cannot exceed four metres in height."

For extensions of more than one storey

Planning Portal stated that extensions of more than one storey "must not extend beyond the rear wall of the original house by more than three metres or be within seven metres of any boundary opposite the rear wall of the house". The roof pitch must correspond with the existing property as closely as possible — this equally applies to any upper storey constructed on an existing extension.

Furthermore, any upper-floor window situated in a 'side elevation' must be obscure-glazed and non-opening. All side extensions of more than one storey require householder planning permission. There are exceptions to all of this, including additional restrictions for properties situated within conservation areas, for instance. Planning Portal also noted that these rules applied in the context of the proposed extension and any previous extensions. They are applicable to houses only.

The rules are a summary of Schedule 2, Part A, Class A of The Town and Country Planning (General Permitted Development) (England) Order 2015 and detailed advice provided by the Government can be found in the ‘Permitted development rights for householders: technical guidance’.

Anyone considering undertaking work should thoroughly examine these rules and documents before proceeding with anything.