Permitted Development for Extensions in Greater Manchester: What to Check First

Overview

Permitted development can be useful when you are planning an extension, but it is not a shortcut around checking the details. It is a set of rules that may allow certain work without a full householder planning application. Whether it applies depends on the house, the proposed extension, previous work at the property and any local restrictions. Two houses on the same road can have different answers.

This guide is for England and is intended to help homeowners in Greater Manchester ask the right questions early. It does not decide whether your own extension is lawful. Before committing to drawings or construction, check the proposal with the relevant council. A lawful development certificate can give formal confirmation that planning permission was not required.

Start with the original house, not the current footprint

The permitted development rules refer to the original house. In simple terms, that means the house as first built, or as it stood on 1 July 1948 if it was built before then. Previous extensions count when the limits are assessed, including work carried out by an earlier owner. This is one reason a design that looks modest can still need planning permission.

The rules are for houses. They do not apply in the same way to flats or maisonettes, and some homes have planning conditions or Article 4 directions that remove or restrict permitted development rights. Listed-building consent and conservation-area controls are separate issues. Do not assume that an extension next door proves the same route is available to you.

Rear extension permitted development limits

For a standard single-storey rear extension, the usual permitted development limit is 4 metres beyond the original rear wall for a detached house, or 3 metres for any other house. The extension must not be more than 4 metres high. These are only part of the test. The proposal must also meet the rules on height, position, coverage of the land and local restrictions.

There is a larger home extension route for some single-storey rear additions. It can allow a projection of more than 4 metres up to 8 metres for a detached house, or more than 3 metres up to 6 metres for any other house. It is not automatic permitted development. The local authority has to be notified through prior approval, adjoining neighbours are consulted and the process must be completed before work begins.

The official starting point is the Planning Portal's guidance on extensions and planning permission. Its separate guide to

prior approval for larger home extensions explains the notification and neighbour-consultation route in more detail.

Can I build a side extension under permitted development?

A side extension may be permitted development only where it is single-storey, no higher than 4 metres and no wider than half the width of the original house. The extension cannot project beyond a side elevation where that side elevation fronts a highway. On designated land, including conservation areas, side extensions need planning permission rather than relying on these householder rights.

This matters when a design is described as a side return or wraparound extension. A side return often takes in a narrow passage beside the house. A wraparound combines rear and side elements. Neither label creates a separate permission category. The complete proposal has to satisfy the relevant limits and conditions, including the effect of earlier extensions and the overall footprint.

Height, coverage and the position of the extension

The extension must not be higher than the highest part of the existing roof and its eaves must not be higher than the existing eaves. Where the eaves are within 2 metres of a boundary, they cannot exceed 3 metres. Extensions and other buildings must not cover more than half the land around the original house. That calculation does not give a free half of the garden. It is part of a wider test and needs to include previous enlargement.

Permitted development does not allow an extension forward of the principal elevation. It also has limits on verandas, balconies and raised platforms. Materials should have a similar appearance to the existing house, subject to the detailed legislation. On a visible rear or side elevation, brick size, colour, mortar and opening positions deserve attention long before the material order is placed.

What changes for a two-storey extension?

A more-than-one-storey rear extension must project no more than 3 metres beyond the original rear wall and be at least 7 metres from the boundary opposite that wall. It must meet other conditions too, including roof-pitch and side-window privacy requirements. A two-storey side extension needs householder planning permission. The planning route should be confirmed before the structural design and construction programme are treated as fixed.

The practical impact is often greater than the headline measurement suggests. A double-storey addition affects the roof, upper-floor layout, foundations, external appearance, overlooking and the relationship with the neighbour.

If you are weighing up the options, read MNB's guide to double-storey extensions in Manchester for the structural-build considerations behind the drawing.

Prior approval is a process, not a verbal assurance

For a qualifying larger rear extension, the applicant submits a written description, dimensions, a plan and information about adjoining premises to the local authority. Neighbours are notified and have an opportunity to comment. If objections are made, the authority considers the effect on the amenity of adjoining properties. Work should not start until the required written outcome is received or the relevant decision period has passed.

This is why it is better to say that an extension may be possible under prior approval than to advertise it as planning-free. A proposal can need changes after the measurements, boundary, design or neighbour impact are considered. The council's written response is the important document, not an early estimate based on a photograph.

Planning permission and Building Regulations are different checks

A project can be permitted development for planning purposes and still need Building Regulations approval. Building control covers the technical construction of the extension, including matters such as structure, insulation, drainage, ventilation, fire safety and the connection to the existing house. The right building-control route should be agreed before site work begins.

GOV.UK explains the separate process for Building Regulations approval. It is also worth checking the current

householder technical guidance if the proposal is close to a limit or combines several elements.

A Greater Manchester checklist before you book the build

Check whether the property is a house and identify any earlier extensions. Measure the proposal from the original rear or side wall, not a later addition. Check the current council position for the address, including any planning condition, Article 4 direction, conservation-area or listed-building constraint. Decide whether the proposal needs prior approval or a householder planning application. Arrange the Building Regulations route and any structural information needed for the build. Consider boundaries, access and Party Wall matters before a start date is set.

The same checklist applies whether you are in Worsley, Salford, Bolton, Wigan, Stockport or Manchester. What changes is the individual property and the local authority that confirms the planning position. A free survey helps identify the practical brickwork and structural-build questions, but MNB Brickwork does not make the planning decision for the council.

For the construction side of the project, see MNB's house extension builders in Manchester service. You can also explore local pages for

Worsley,

Salford and

Stockport.

The rules in this article are a guide to England's current householder permitted development framework, not a site-specific decision. Check the exact proposal with the relevant local planning authority or apply for a lawful development certificate before relying on permitted development.

When you are ready to discuss foundations, brickwork, structural openings and the external shell, request a free survey or call MNB Brickwork on 07821 482488.