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Will I need Planning Permission for my Extension?

Planning permission can be a thorn in the side of home owners, developers and even architects.

If you fail to get approval for a project it can increase the timeframe and cost.

Fortunately, Thames Design and Build can help as our main area of expertise is extensions.

A good extension can add a lot of value to a home but you must ensure you get planning permission if it is necessary.

Not every project will require planning in some cases the project will fall under permitted development, meaning you get your extension built without applying for permission.

When is an extension a permitted development?

If the design of your extension meets certain criteria you will not need planning permission. For example it must not:

Cover more than half of the land around the house.

Extend above the highest point of the roof.

Be over four metres high if it is a single storey extension.

Extend too far beyond the rear wall of a property - three metres for an attached house and four metres for detached.

Be closer than seven metres to the rear boundary if it is a two storey extension.

Have materials that differ from those in the original building.

The best place to look for more info on permitted development rights is the Planning Portal. There is a section for extensions here is the link:

Other considerations

The permitted development rights above and on the Planning Portal only apply to houses, the rules are different for flats and maisonettes.

There are also much stricter rules if you live on designated land, including conservation areas, national parks, and Areas of Outstanding Natural Beauty.

If your home is a listed building you also have fewer rights so will require permission for most projects.

Two of the most vital things to think about with any extension are overlooking as well as overshadowing. Your project is more likely to get planning permission if it does not overlook or overshadow a neighbouring property. There are many ways you can design it to avoid both of these or minimise the severity.

Choose a reliable company

Thames Design and Build has a lot of experience with getting planning permission for extensions.

Where Planning Permission is required, we will submit the plans on your behalf, and will monitor the progress of the application. Should the Planning Officer require amendments, we will in most instances prepare amended plans without additional charge. While it is difficult to generalise, our experience of 'first time passes' is in excess of 90%, and in most other cases

plans will be approved on the back of relatively minor alterations.

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