Yes, and did the consultation/survey.

Rgds

Damon

Posted By: cjardAlso the doc says elsewhere that sone of the backlash from big building is that there aren't enough people available to install heat pumps - surely this is BS, as you need fewer certifications to install a monobloc ASHP than you do a gas boiler (no corgi, just a g3 for pressurised systems, itself not needed if an open vent TS is used but how many gas boiler installers don't have a g3

I expect they're talking about F gas certification.

Agree with the rest of your post though.

I don't understand the logic of allowing party walls to be less insulated. Yes, if there's somebody living next door and they heat their house then the heat loss will be less, but I think it's better to treat that as a bonus. Sometimes houses are left empty, or even one-half of a pair is knocked down for some reason, so it seems better to me to leave it the same standard as other walls. A party wall already need to meet stricter requirements for noise insulation anyway, so I'd expect that bringing the thermal insulation up to standard wouldn't be terribly difficult. So the goverment proposal makes more sense to me.

I think a max U-value of 0.1 in every region is unduly strict for the building regs backstop. It might be necessary in some parts of the country, but not in sheltered southern locations. Specifically I wouldn't have been able to build my house with that limit. I'd prefer a whole building heat loss limit as calculated by PHPP, or at worst a more realistic limit such as 0.15, but unless windows and doors are tightned up even that doesn't make much sense.

Those are the worst allowable area weighted limiting values I'd note (although they are still worse than those already currently in place in Wales or Scotland).

The notional building fabric U-values (windows, doors, walls, roofs and floors)for the two options consulted upon, combined with tighter thermal bridging should result in overall improvements compared to current levels. The fabric in Option 1 is better, but Option 2 uses a PV requirement for target setting (not actually required, just sets the targets).

(See Appendix R of https://www.bregroup.com/wp-content/uploads/2019/10/SAP-10.1-10-10-2019.pdf for notional packages used for target setting).

FYI, the consultation for this has been extended to Feb 7th. I encourage you to chip in if you haven't already!

https://www.gov.uk/government/consultations/the-future-homes-standard-changes-to-part-l-and-part-f-of-the-building-regulations-for-new-dwellings

It is sort of satisfying to reach the end of it though, having slagged off all their targets as not ambitious enough :-)

Posted By: bhommelsIt is sort of satisfying to reach the end of it though, having slagged off all their targets as not ambitious enough :-)

Inspired me - that was an ordeal - but at least prompted me to learn what pulse air leak tighness testing was.

Posted By: DarylPa blind-alley waste of time...? '-)

DP Can you elaborate? I'm genuinely curious to know whether the pulse approach is complete bobbins...

... I should point out that we were approached by the university that started this a year or so back, to see if we wished to collaborate in development/testing. I asked about the principles behind the theory, but could not understand how it could work? Maybe someone here who knows more than me could explain?

I thought this paragraph was interesting

"As part of the Pulse trial the team have each had their own homes tested, a Victorian terrace, a 1970’s and a 2014 mid-terrace new build. As you can imagine we thought the winners was assured, especially with a SAP certificate recording airtightness at 5.8m3/h/m2. The results for the new build came back 10.8m3/hm2 this means it fails building regulations and shows that the building industry still aren’t understanding the importance of making a home airtight and taking the time to achieve these low air leakage values. The results of the Victorian terrace 10.7m3/h/m2 and the 1970’s build 7.9m3/h/m2"

It's strikes me that they should have tested each of these with a blower door to see if it gave the same results. Frankly I'm amazed that the Victorian was so close to building regs (and 70's met it) unless a fair bit of work had been done to them. More worrying that a 2014 build was so far off the original SAP and that they didn't seek to find out why.

I think the 60's and 70's had good houses for air tightness. Old Victorian houses have wooden floors, and "character" leaky windows. More modern ones have dot and dab walls. The 60's and 70's stuff has wet plaster walls, and concrete floors - they can be improved on, but the starting point is better.

I'm halfway through the survey, it is getting a bit tedious trying to answer silly questions when the poor fabric insulation issue glaringly dominates.