EWI below DPC worth it?

[Linto]

Hi,

I'm wondering if it's worth putting EWI (150mm) under the DPC on my walls or should I just improve the underfloor insulation and just accept a massive ledge at the dpc level when I install it above the EWI.

If I do extend the EWI below the dpc would I need to keep the subfloor airbricks open? As in my mind it would make the point of the EWI below the dpc pointless if they remained open?

I've read about people extending the EWI all the way down to the foundations but this isn't really financially viable all the way round with having to install French drains etc but I will be looking to move the drains out so that the gutters run straight down and end the EWI at ground level.

I hope the attached picture helps provide some idea of what I'm talking about.

 

 

[Ferdinand]

Normal reasons for round-the-edges would be as Plan B if you can’t do underfloor, or Plan Supplementary If the amount you can fit is limited.

 

It also depends on what is under the floor.

 

F

[Linto]

Thanks Ferdinand,

I can insulate the underfloor as it's largely soil with a decent crawl space below the floor boards so I should be able to do it myself with 100mm of mineral wool. It will just be awkward to get everything though the small hatch. 

Does anybody have any ideas on what can I do to reduce what will be a large unsightly step from the EWI to the wall?