window/door frames overhanging wall cavity

[WWilts]

Is the 30mm minimum overhang for window frames part of Building Regulations? (Of course maximum overhang is best, that is not the question)

Is the 30mm minimum overhang of cavity for window frames applicable to door frames too?

 

Just trying to lay down the law to window/door installers

 

[nod]

30 is fine 

Ours are quite narrow frames and I fixed them inline with the inner edge of the outer leaf