Specific Planning Rules for Multi-Storey Extensions

If you're planning to add an extension with more than a single storey to your home, there are some particular regulations you must follow:

• First, the rear wall of your new extension cannot extend more than three metres beyond the rear wall of what's defined as the 'original house'.

• Secondly, you need to ensure that your extension stands at least seven metres away from any boundary line that is directly opposite the rear wall of your property.

• When it comes to the roof, its slope or 'pitch' should match that of your existing house as closely as practically possible. This specific requirement also applies if you are building an additional storey on top of an extension that's already there.

• Any window on an upper floor that faces sideways (a 'side elevation') must be fitted with obscure glass – meaning it's not transparent – and must not be able to open. The only exception is if the opening part is situated more than 1.7 metres above the internal floor level.

Beyond these design rules, it's also crucial to understand when you'll need formal planning permission:

• For all side extensions that have more than a single storey, you will be required to apply for 'householder planning permission'.

• Furthermore, if your property is situated on what's designated as 'Article 2(3) land', you must obtain 'householder planning permission' for any rear extension that boasts more than one floor.