Insulating below DPC - cavity wall construction

[HughF]

I know there is a real benefit to insulating below DPC, and for various reasons, we haven't done so on our extension. Is this something that I can get done as a retrofit, using blown in EPS beads? Assume that holes will need to be drilled below DPC in the blockwork that comes off the founds. Cavity is 150mm full fill rockwool, with I think one course of air below the rockwool before you hit the cavity concrete fill.

Edited September 19, 2023 by HughF