So… somewhere between my contractor, the builders merchant and the manufacturer, they’ve ordered the wrong wall insulation.

 

Whilst what they have ordered doesn’t have a significant difference in u-value (0.021 vs 0.02) when I scale this out across the entire build envelope it does take it above the threshold we set for SAP etc. Plus I’m a little loathed to compromise on something that is going to have to last the life of the house. 
 

The correct one will take 10-20 days to be manufactured and shipped from Ireland to us which has impact on brickies who were due to start on Monday to build ground floor walls. 
 

Bit of a long shot but does anyone have some Unilin ECO360 CavityTherm ECO/CT 150mm that they aren’t needing just yet? We can get ours ordered and then do a swap once it arrives or have delivered to you to replace. 

Sadly the bricklayers will find it very hard to work with and detail.  I have never seen this installed correctly.  You would be better off using Dritherm 32 batts, which are far easier to install.  You will get a much better actual result.