Increasing the size of a window will often fall under permitted development rights, meaning an application for planning permission is not required to make the change, provided limits and conditions are met.

Any new window must be of similar appearance to the original which you are replacing.

Permitted development rights do not apply to flats. To increase the size of a window in a flat or maisonette you will require planning permission.

 If you live in a listed building, you will require listed building consent for any major changes.

Where the work has as significant impact on the external appearance of the house, especially on the principal elevation, planning permission may be required.

Building control approval will likely be required where the change impacts the structure of a building, this primarily occurs when an opening Is widened. When altering walls you may want to consult a structural engineer.

Building control will also consider energy efficiency, glazing, ventilation and fire safety.

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

A pergola is classed as permitted development, meaning an application for planning permission is not required provided it meets specified conditions and limits.

Outbuildings cannot be installed on the principal elevation of the property, additionally any platform must not exceed 0.3 metres in height.

If the building is listed, then you will need to apply for listed building consent and planning permission for the change.

For more details read our outbuildings common project.

Planning permission is not normally required for steps in a garden, however, permission may be required if the steps are part of a larger project such as a raised deck attached to the front of the house.

If the external steps are attached to the house and a roof is constructed, this will become a porch which has different rules attached. Read full details on the planning rules for porches in our common projects section.

Different rules may apply if you live in a designated area such as a conservation area or if the building you live in is listed.

External steps will not normally require building regulations approval unless they are part of the access to the building. If they are then you must ensure that you do not reduce the level of accessibility to the house.

You should contact your local planning authority for further project advice, alternatively, you can apply for a lawful development certificate for confirmation that any changes you make do not require planning permission.

Once submitted, your planning application first goes through a validation process. After its validated, the formal decision period is 8 weeks. However, in some cases, especially for more complex proposals or if further information is needed, your local authority may request an extension of time.

Understand more about the decision-making process on Planning Portal