Whether you need planning permission for a loft conversion in the UK depends on your property and scope of the work. Many loft conversions are allowed under Permitted Development Rights (PDRs) – meaning no planning permission is needed but there are strict limits.

You Do Not Need Planning Permission If:

Your loft conversion meets the permitted development criteria:

1. Volume limit:

• Up to 40 cubic metres for a terraced house
• Up to 50 cubic metres for detached or semi-detached houses.

2. Design:

• The extension does not exceed the existing roof height.
• Dormers or roof extensions are set back at least 20cm from the eaves.
• Materials must be similar to the existing house.
• No verandas, balconies or raised platforms including juliet balconies.

3. Side facing windows:

• Must be obscure-glazed and non-opening unless 1.7m above the floor.

4. Not in a designated area:

• No PD rights for flats, listed buildings or in conservation area, AONBs etc.

You Will Need Planning Permission If: 

• You want to raise the roof height
• The volume exceeds the PD limits.
• You’re adding balconies or terraces.
• Your property is in a designated area.
• The loft design is significantly different (e.g. front-facing dormer).

YOU SHOULD APPLY FOR A LAWFUL DEVELOPMENT CERTIFICATE (LDC)

Even if PD applies, DWG Plans suggests that an LDC is applied for. This confirms that that work is legal under the PD rights which is useful when selling your home. It also gives you peace of mind.

Other considerations would be building regulations approval. This is always required for lofts and covers such things as fire safety, insulation and stairs.

You may also need party wall agreement if you share a wall with a neighbour.

Why not get in contact with DWG Plans and we can help you with plans and building regulations for your loft conversion.

Call DWG Plans on 0800 688 9345 or get in touch online today.