Timber frame sitting on existing cavity wall up to DPC

[Timberframeguy]

Hi all,

 

I have an existing brick & block single storey rear extension which I am looking to take down to the DPC level and re-do in a timber frame/timber clad construction using 150 timbers.

 

Can anyone help me with the detail on fixing a 150 timber sole plate down onto the existing brick/block work above the DPC? The total width of the existing wall is 240mm including a 60mm cavity.

 

Thanks!