Do I need planning permission for a loft conversion in Manchester?

Many loft conversions in Manchester do not need planning permission because they fall under permitted development. But some do, and every loft conversion needs Building Regulations approval. This guide explains the difference.

The short answer

A loft conversion is usually permitted development if the extra roof space stays within 40 cubic metres on a terraced house or 50 cubic metres on a semi-detached or detached house, nothing extends beyond the front roof slope facing the road, and the other conditions below are met. Front dormers, mansards, flats and many homes in conservation areas need planning permission.

Permitted development conditions for loft conversions

• The volume limits above, including any previous roof extensions.
• No part of the extension can be higher than the highest part of the existing roof.
• Nothing can extend beyond the plane of the existing roof slope at the front of the house where it faces a road.
• Materials should look similar to the existing house.
• No verandas, balconies or raised platforms.
• Side-facing windows must be obscure-glazed, and non-opening unless the opening part is more than 1.7 metres above the floor.
• Except for hip-to-gable work, the roof extension should be set back at least 20cm from the eaves, as far as practical.

Dormers, hip-to-gables and rooflights

Rear dormers are the most common permitted development loft conversion. A dormer loft conversion on the back of a terrace or semi usually fits within the rules. Hip-to-gable conversions on semis are also often permitted, and are frequently combined with a rear dormer. See hip-to-gable loft conversions.

Rooflight conversions change the roof least of all. Rooflights must not project more than 150mm from the roof slope. Read more about Velux loft conversions.

When you will need planning permission

• Front dormers, or anything that extends the roof slope facing the road.
• Mansard conversions, which usually change the roof shape too much for permitted development.
• Homes in conservation areas, such as parts of Didsbury, Chorlton Green and the Heatons.
• Flats and maisonettes.
• Listed buildings, which also need listed building consent.
• Properties where permitted development rights have been removed.

Even where planning is not needed, a Lawful Development Certificate gives you written confirmation from the council, which helps when you sell.

Building Regulations for loft conversions

Every loft conversion needs Building Regulations approval. The main areas are:

• Structure: new floor joists, steel beams and support for the roof, designed by a structural engineer.
• Fire safety: a protected escape route, usually fire doors to habitable rooms off the stairway and mains-wired, interlinked smoke alarms.
• Stairs: a permanent staircase with adequate headroom. The rules allow slightly reduced headroom for loft conversions where the roof slopes.
• Insulation and ventilation: the roof, dormer walls and floors must meet current energy standards.

We manage all of this with Building Control. Our Building Regulations guide explains the process.

Party walls

If you live in a semi or terrace, the steels for your loft are often supported on the party wall, so you will need to serve party wall notices. See party wall agreements explained.

Thinking about a loft conversion?

We check the planning position, design and build loft conversions across Greater Manchester. Find out more about our loft conversions or book a free site visit.