Insulating floor around constructional hearth

[TonyS82]

I am currently lifting floor boards to insulate between the joists in my living room.

Does anyone know if there are specific regulations for insulating under floorboards around a constructional hearth for an open fire?

We are intending on fitting a wood burning stove at some point and wanted to get this right before relaying the flooring.

I will be using non combustible mineral wool for insulation.

Image attached of the hearth in question.

Thanks

 

[blup]

I believe the regs govern insulation below the hearth rather to the side

Blup