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Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
These two books are the perfect starting place to help you get to grips with one of the most vitally important aspects of our society - our homes and living environment.

PLEASE NOTE: A download link for Volume 1 will be sent to you by email and Volume 2 will be sent to you by post as a book.

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    •  
      CommentAuthordjh
    • CommentTimeOct 9th 2019
     
    Has anybody looked at The Future Homes Standard: changes to Part L and Part F of the Building Regulations for new dwellings ?

    Research into ventilation and indoor air quality in new homes
    Research into overheating in new homes

    https://www.gov.uk/government/consultations/the-future-homes-standard-changes-to-part-l-and-part-f-of-the-building-regulations-for-new-dwellings
    •  
      CommentAuthorDamonHD
    • CommentTimeOct 9th 2019
     
    Yes, and did the consultation/survey.

    Rgds

    Damon
    • CommentAuthorcjard
    • CommentTimeOct 12th 2019
     
    From the Consultation doc:

    Table 3.1 - Minimum standards for fabric performance

    External walls 0.26 W/m2.K
    Party walls 0.20 W/m2.K
    Floor 0.18 W/m2.K
    Roof 0.16 W/m2.K
    Windows 1.6 W/m2.K
    Roof-lights1 2.2 W/m2.K
    Door 1.6 W/m2.K
    Air permeability 8m3/m2.K at 50Pa

    The proposed walls value could be better but that air permeability is nearly as much of a joke as the existing standard, no?

    Also 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

    What we actually probably need is training courses for Joe Public on "how to live in a low energy home" to get them out of the "get home and blast the 28kw boiler at full tilt for 3 hours" mindset
    •  
      CommentAuthordjh
    • CommentTimeOct 12th 2019
     
    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.
    • CommentAuthortony
    • CommentTimeOct 12th 2019
     
    The U - values are in sufficiently good, and like you say air tightness is a JOKE

    For me walls, floors and ceilings less than 0.1, party wall can be 0.2 air tightness ONE
    •  
      CommentAuthordjh
    • CommentTimeOct 12th 2019
     
    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.
    • CommentAuthortony
    • CommentTimeOct 13th 2019
     
    When the house is empty it still resists heat loss unless all the windows are open effectively the U value is much better than the 0.2 of the wall itself
    • CommentAuthorSigaldry
    • CommentTimeOct 15th 2019 edited
     
    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).
    • CommentAuthorcjard
    • CommentTimeOct 28th 2019 edited
     
    Posted By: djh
    I expect they're talking about F gas certification.


    F has only needed for split systems though and I'd wager the majority of installs these days are monobloc
    • CommentAuthorTimSmall
    • CommentTimeJan 16th 2020
     
    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
    • CommentAuthortony
    • CommentTimeJan 16th 2020
     
    you have to be made of strong stuff to that, the consultation is way too long

    Tony
    • CommentAuthorbhommels
    • CommentTimeJan 16th 2020
     
    It is sort of satisfying to reach the end of it though, having slagged off all their targets as not ambitious enough :-)
    • CommentAuthortony
    • CommentTimeJan 16th 2020
     
    πŸ™‚. πŸ˜‚πŸ€£πŸ˜‚
    • CommentAuthorjms452
    • CommentTimeJan 17th 2020
     
    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.
    • CommentAuthorDarylP
    • CommentTimeJan 17th 2020
     
    a blind-alley waste of time...? '-)
  1.  
    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...
    • CommentAuthorDarylP
    • CommentTimeJan 17th 2020
     
    ... simples... how can you determine where the leaks are? :shamed:
    • CommentAuthorDarylP
    • CommentTimeJan 17th 2020
     
    ... 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?:cry:
    •  
      CommentAuthordjh
    • CommentTimeJan 17th 2020
     
    Interesting - I hadn't come across the idea before.

    There's a pretty good explanation at https://www.ecodesignconsultants.co.uk/airtightness-testing/ (though you have turn off formatting if you have JS disabled. :devil: :angry: )

    Advantages:
    - it's quick and presumably cheaper, so should be able to be applied to all houses. It might be worth testing its limits though - minimum and maximum volumes of buildings, minimum and maximum airtightness.
    - it tests all doors and windows, doesn't need to replace one

    Disadvantages:
    - as already stated, it gives very little opportunity to locate the leaks, so would need another visit with a blower door to remedy any failures. That should become less of a problem over time as people learn what they have to do
    - it tests at a low pressure and positive pressure only, so won't test poorly adhered tapes or flap-type leaks that only open on negative pressure

    So I guess it might be applicable for UK gov-mandated tests if they change the pressure requirements. Not valid for PH tests though because of the lack of negative pressure.
  2.  
    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.
    •  
      CommentAuthordjh
    • CommentTimeJan 17th 2020 edited
     
    Posted By: Simon StillIt's strikes me that they should have tested each of these with a blower door to see if it gave the same results.

    That is a very good point!
    • CommentAuthorRobL
    • CommentTimeJan 17th 2020
     
    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.
    • CommentAuthorjms452
    • CommentTimeJan 17th 2020 edited
     
    Posted By: Doubting_ThomasCan you elaborate? I'm genuinely curious to know whether the pulse approach is complete bobbins


    Releasing extra air into a house and watching the pressure decay could give you information about the leakage if you know the internal volume, make some assumptions about the shape and leave all internal doors open. Accuracy will be challenge though.

    Given I'd just said that every house should be tested I rated it as positive but commented that extensive equivalence with blower door would need to established.
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