Shed height and planning permissions

[functor]

Hello,

I am planning a shed which fits under permitted development - minus one thing. The height of the shed. The law says 2.5m height (for within 2m of the boundary), but because this is a gym I ideally want 2.5m - 3m usable height.

With slab / flooring and roofing... I would have to subtract 500mm from the 2500mm allowance. Do I have to make a full planning permission application if I want to request 3.5m height?

Can I instead dig deep and make the shed 1m underground? Would that cause issues?

Thanks

 

[nickjb]

It's measured from the highest adjacent ground so you would effectively lose the slab and floor thickness. Digging down is a workaround but will be loads more expensive than a planning application. Any reason to think you wouldn't get planning? It would be a full application but these can be quite sketchy as long as you have all the relevant information,

 

[functor]

I might as well do the application if digging is more expensive. Would I also need buildung regulations?

 

[nickjb]

If it is not combustible (e.g. blockwork) then you can build up to 30m2 without regs. For wood you can go up to 15m2. Either way you will need regs for electrical work.

 

[functor]

But the roof will still have timber in it for the joists, does it still count as non combustible?

 

[tony1851]

But the roof will still have timber in it for the joists, does it still count as non combustible?

The rules state that the building must be built of 'substantially non-combustible material'
This has caused confusion as it is open to interpretation and many councils have different views.
But the roof is less of a fire risk to an adjoining building than the walls. Most roofs have timber in them so, whether the roof is flat or pitched, it would be an unreasonable inspector who would not accept it.
If it is a tiled pitched roof, you should certainly have no problem.