Loft Conversion - 50 Cubic Metre Rule

[RonnyRaygun]

I am helping a friend out with a loft conversion. Currently just doing some plans for him but he asked me whether planning permission would be required.

I said no, but then thought about the 50 cubic metre rule. This conversion will be a lot more than 50 cubic metres in total, so my first thought was that planning permission would be required.

However, the roofline itself is not being altered at all, so I am not sure if it is still the case.

To me, even the Planning Portal is not clear:
1. Loft conversions are NOT permitted development for houses on designated land.
2. To be permitted development any additional roof space created must not exceed these volume allowances: • 40 cubic metres for terraced houses. • 50 cubic metres for detached and semi-detached houses.

So, my question is, does condition 2 mean:

• additional habitable space?
• additional roof space such as dormers etc?

Thanks in advance!

 

[Nakajo]

It's not additional roof space, so no. Additional roof space would be dormers, etc.

 

[DevilDamo]

To clarify the cu.m relates to changes to the roof shape/profile via hip to gable roof extensions, dormers, etc... It does not relate to the additional floor space created within an existing roof. The only time this does come into play is if there is a previous Planning condition that prevents or restricts loft conversions.

 

[RonnyRaygun]

Thanks both. I thought that was *probably* the case, but wanted to be sure after telling him he wouldn't need PP and then having concerns that there might be some restriction on huge loft conversions.