30m2 Floor area for outbuilding

[JT101]

I am aware this has been discussed many times on here but I have a slightly different quirk.

I want my outbuilding that I plan to construct in the back garden to have an internal floor area of less than 30m2 to avoid having to go through building control

However, there is also a window seat which isn't in the same envelope as the 30m2. Since it isn't part of the floor, does it count?

Thanks

 

[^woody^]

There are other criteria to the 30m2, not just that in isolation.

The 30m2 is internal area between the walls and includes any bows or bays.

 

[JT101]

Thanks