Do Flats and Maisonettes Have Permitted Development Rights?

Flats and maisonettes do not benefit from the same householder permitted-development rights as individual houses.
 

An extension to a ground-floor flat, maisonette or converted property will normally require planning permission.
 

This remains the case even where a similar extension to a house might have been permitted development.
 

Leasehold consent, freeholder approval and the relationship with other residents may also need to be considered.

 

What About Conservation Areas?

Living in a conservation area does not automatically prevent you from extending your home.
 

However, some permitted-development rights are more restricted in designated areas, and the design may need to respond more carefully to the character of the property and its surroundings.
 

Side extensions, more substantial rear extensions and highly visible alterations may require closer attention.
 

The local authority may also have introduced an Article 4 Direction removing certain permitted-development rights in a particular street or neighbourhood.
 

Where a property is in a conservation area, it is sensible to check the local position before assuming that the standard rules apply.

 

Listed Buildings

A listed building requires particular care.
 

Planning permission and listed-building consent are separate matters.
 

Even relatively modest alterations may require listed-building consent where they affect the character or historic fabric of the property.
 

This can include changes to external walls, windows, doors, roof structures and internal layouts.
 

A homeowner considering an extension to a listed building should obtain specialist advice at an early stage rather than progressing with a standard extension design.

 

Article 4 Directions and Removed Permitted Development Rights

Permitted-development rights are not always available.
 

A local authority may introduce an Article 4 Direction restricting certain types of development in a particular area. This is often used where additional control is needed to protect the character of an established neighbourhood.
 

Permitted-development rights may also have been removed by a condition attached to an earlier planning approval.
 

This is particularly relevant for some newer housing estates, converted buildings and properties with a more complex planning history.
 

Checking the council’s planning records early can prevent wasted design work and unrealistic assumptions.

 

Does Planning Permission Guarantee That the Extension Can Be Built?

Planning permission is only one part of the process.
 

An extension may also require:
 

• Building Regulations approval;

• structural calculations;

• party wall advice;

• freeholder or landlord consent;

• Thames Water or drainage considerations;

• tree-related checks;

• flood-risk advice;

• specialist input where the property is listed or in a sensitive location.
   

Planning permission considers whether the extension is acceptable in principle.
 

Building Regulations deal with how it will be designed and constructed, including foundations, structural work, insulation, drainage, ventilation and fire safety.
 

Most house extensions need Building Regulations approval even where planning permission is not required.

 

Should I Apply for a Lawful Development Certificate?

Where an extension falls within permitted-development rules, it is often sensible to apply for a Lawful Development Certificate.
 

This provides formal confirmation from the local planning authority that the proposed work is lawful.
 

An extension does not become lawful simply because a certificate is issued. The certificate records the legal position based on the submitted drawings and information.
 

However, it can be extremely useful.
 

A Lawful Development Certificate may help:
 

• confirm the planning position before building work begins;

• reassure a builder, lender or future purchaser;

• reduce uncertainty during a property sale;

• provide a clear record of what was approved;

• avoid disagreements later about whether the extension complied with permitted-development rules.
   

For a substantial investment such as a house extension, relying on an informal assumption can be a false economy.

 

Do I Need Planning Permission for Internal Alterations?

Internal layout changes within a house do not usually require planning permission.
 

For example, removing an internal wall, enlarging a kitchen or relocating a doorway will not normally require a planning application.
 

However, Building Regulations approval may still be required, particularly where load-bearing walls are removed, structural steelwork is introduced or fire-safety arrangements are affected.
 

Listed buildings are different. Internal changes may require listed-building consent even where planning permission is not needed.
 

Flats and maisonettes may also involve leasehold, freeholder or building-management considerations.

 

Do I Need Planning Permission for Rooflights, Glazing and Doors?

Windows, rooflights and external doors can sometimes be included within an extension proposal or installed under permitted-development rights.
 

However, the position depends on the property and the location of the alterations.
 

Side-facing windows may require obscure glazing and restrictions on opening. Changes to the front elevation may be more sensitive. Listed buildings and homes in conservation areas require additional care.
 

Where large areas of glazing are proposed, Building Regulations will also need to be considered. Heat loss, overheating, safety glazing and ventilation may all affect the final design.

 

Can I Build the Same Extension as My Neighbour?

A neighbouring extension can provide a useful reference point, but it should not be treated as an automatic precedent.
 

Your neighbour may have:
 

• submitted a full planning application;

• used permitted-development rights;

• obtained prior approval;

• built the extension many years ago under different rules;

• benefited from a different original house layout;

• completed work before an Article 4 Direction was introduced;

• secured approval for a design that would not necessarily be accepted today.
   

The neighbouring property may also have a different relationship with boundaries, windows, trees or surrounding homes.
 

The safest approach is to assess your own property properly.

 

What Drawings Will I Need?

The drawings required will depend on the planning route.
 

A householder planning application will normally need clear existing and proposed drawings showing the property, the extension and its relationship with the surrounding site.
 

A permitted-development Lawful Development Certificate application also needs accurate drawings so that the council can confirm whether the proposal complies with the rules.
 

A prior-approval submission for a larger rear extension requires sufficient information for the local authority to consult neighbours and assess the proposal.
 

Planning drawings are not the same as Building Regulations drawings.
 

Once the design and planning route have been resolved, a more detailed technical package may be required before builders can quote accurately and construction can begin.

 

Start with a Proper Assessment

The planning route should be established before the extension design is pushed too far.
 

In many cases, a homeowner will have more than one option.
 

A modest rear extension may fall within permitted-development rights. A slightly larger extension may require prior approval. A more ambitious scheme may justify a full planning application because it creates a better layout and adds more value to the home.
 

The right decision depends on the property, the budget and the priorities of the household.

 

Planning a House Extension?

Tell us a little about your home, the type of extension you are considering and the stage you have reached.
 

APN Extensions can help you understand the likely planning route and identify the professional support that may be useful for your project.