Greengauge (@greengaugebec.bsky.social)

We were approached recently to undetake a thermal bridge calculation for an as-built EWI detail that 'leaves a little to be desired'. It's not quite as plainly and shockingly awful as some of the… | Toby Cambray We were approached recently to undetake a thermal bridge calculation for an as-built EWI detail that 'leaves a little to be desired'. It's not quite as plainly and shockingly awful as some of the details at the infamous Fishwick project, but not far off. The installation simply had not been thought through, or if it had, the answer was a proverbial shrug of the shoulders and a significant risk of rain getting behind the EWI. It involves a bay window, which is really difficult to Externally Insulate to to a good standard. I have direct personal experience of this, having wrestled with it on my own deep retrofit. It's so hard to do well that I gave up and demolished the damned thing and turned it into a regular picture window - the photos are during and after to show what's possible. The install we'd been asked to assess had been flagged as a thermal bridge risk. But from my experience I can say it's probably OK in terms of fRSi - i.e. not a major risk of surface mould because the existing masonry tends to conduct heat into the cold point to keep the temperature up. It might have been a whopper of a chi-value, but I seriously doubt whether a whole-building energy model had been done and if someone would plug our expensive chi-value back in to get it over some EPC threshold. We turned the down the thermal bridge calculation; we don't want to validate bad practise and don't want the risk of a rain ingress issue coming back against our finding of a low risk of mould (which in the absence of rain ingress, it probably would be). Look: I get it. the funding mechanisms and procurement processes mean that its not viable to do this stuff properly* But there's not the appetite for the cost or hassle. I understand a huge amount of resource is going into picking up problematic EWI at the moment, to the detrment of some other important initiatives. But the fact we've been asked to assess this problematic install in this way is a red flag in itself - the reviewer didn't pick up the much more important risks the install posed. It does not give me faith that the oversight is fit for purpose - maybe this is just an N of 1 and you people can tell me that I've got it all wrong? * good/best practise is a movable feast but I would consider it to be to either lose the bay window entirely (notwithstanding the cost, disruption and (percieved?) loss of amenity to the occupant) or take down the window and roof/canopy and rebuild the top half to suit the EWI, https://www.linkedin.com/posts/toby-cambray-19137bb3_we-were-approached-recently-to-undetake-a-activity-7368704838857175040-AuC-?utm_source=share&utm_medium=member_desktop&rcm=ACoAAASUzEsB_kmTt4k63Q3a3uwYkizVVhfJK4c