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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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    • CommentAuthortony
    • CommentTimeJan 21st 2021
     
    Proposed

     
    Draft Future Homes Standard specification
     
     
    Floor U-value (W/m2.K) 0.11
    External wall U-value (W/m2.K) 0.15
    Roof U-value (W/m2.K) 0.11
    Window U-value (W/m2.K) 0.8
    Door U-value (W/m2.K) 1.0
    Air permeability (m3/(h.m2) 5.0
    Heating appliance Low-carbon heating (e.g. Heat pump)
    Heat Emitter type Low temperature heating
    Ventilation System type Natural (with extract fans)
    PV None
    Wastewater heat recovery No
    y value (W/m2.K) 0.05

     
    ENERGY USE REDUCTION - ENERGY DEMAND REDUCTION  should be the number one priority 
     
    Floor U-value (W/m2.K)    0.1
    External wall U-value (W/m2.K)    0.1
    Roof U-value (W/m2.K)    0.1
    Window U-value (W/m2.K)    0.7
    Door U-value (W/m2.K)    1.0
    Air permeability (m3/(h.m2)   1.0 or less
     
    ventilation with Heat recovery essential
     
    no more dormer windows unless U =0.1 for walls and roof
     
    same for extensions 
     
    The elephant in the room seems invisible, action on the existing stock is needed (some use it leverage poorer standards for new build).
     


     
    • CommentAuthorJonti
    • CommentTimeJan 22nd 2021
     
    All of which is pretty academical so long as the enforcement of building quality is so lax.
    • CommentAuthortony
    • CommentTimeJan 22nd 2021
     
    What enforcement?
    • CommentAuthorHollyBush
    • CommentTimeJan 22nd 2021 edited
     
    Sorry I am a bit out of touch with this now - some thoughts:
    1 - are these as built values at point of inspection, or in use by normal person? (Taping holes seems mad when testing, but I think that is done for example)

    2 - is there anything to assess medium or long term compliance - thinking here that a normal home owner would expect the same after 10 years, but experience says a cheap door will warp, windows lose gas etc etc - something should cover the long term and help home owners maintain or have assurance how long these will last before degrading

    Maybe a sperate conversation?
    • CommentAuthortony
    • CommentTimeJan 22nd 2021
     
    LOL as built is always way short of as designed!! It is called 'the performance gap' there are no plans to close this, enforce or even check buildings other than with the existing statutory nspections that produce the gap in the first place,

    some lip service but no teeth or carrots
    • CommentAuthorjms452
    • CommentTimeJan 23rd 2021
     
    Nice summaries Tony - do you have the headlines for the current regs?
    • CommentAuthortony
    • CommentTimeJan 23rd 2021
     
    Sorry no, I always aim to be a lot better than regs, they are minimum requirements and rarely met in practice.
    • CommentAuthorSimonD
    • CommentTimeJan 23rd 2021
     
    There was an interesting Guardian article aligned to this today.

    https://www.theguardian.com/environment/2021/jan/23/buyers-of-brand-new-homes-face-20000-bill-to-make-them-greener

    Interestingly they say that building a house to 'high energy efficiency standards' and using heat pumps instead of gas boilers would only cost and extra £4,800. I think that's got to be a rather optimistic figure.

    I wouldn't argue against improving the energy efficiency of homes but I do wonder about whether the way we put together our standards is fit for purpose. I think we should be looking to design homes according to maximum energy consumption rather than u-values. If the homes use significantly more energy than designed, it's up to the developer to resolve the problem. Perhaps that might focus their attention on building better quality homes. U-values I think are just too theoretical.
    • CommentAuthortony
    • CommentTimeJan 23rd 2021
     
    I like energy use reduction, the problem with maximum energy consumption is that it is a choice, the warmer it is the more energy is needed.

    There is also sadly a problem with theoretical U-values and as built performance.

    I foresee tax on energy consumption but difficult to do equitably
    •  
      CommentAuthordjh
    • CommentTimeJan 23rd 2021
     
    Posted By: SimonDIf the homes use significantly more energy than designed, it's up to the developer to resolve the problem.

    The problem there is the users. The energy used is controlled by the people that live there, and their criteria vary. Some people are happy to leave the heating off in most conditions and just put on extra layers and tolerate the temperature. Others, like me, have the irrational goal of keeping the temperature as close to but above 20°C at all times to meet an arbitrary standard. Still others insist on wearing a T-shirt and shorts at all times and maintaining the temperature to suit.

    It's difficult to see why the developer should be responsible for that.

    Certainly I'd support a move to test say the power required for the house to maintain a temperature of 10°C above ambient, but I expect there are lots of problems with trying to define that exactly.
  1.  
    Should be easy to log the inside and outside temperatures and energy consumption for the first month/year of occupancy and compare (energy/DeltaT) against a legal standard?

    As was mentioned, most of the UK's housing stock for 2050 has already been built. So wrangling about new build standards maybe missing the point, it's the renovation standards that matter. A surprising number of threads on GBF are about retro fit insulation, where they don't intend to comply with building regs/stds insulation values.
    • CommentAuthorjms452
    • CommentTimeJan 23rd 2021
     
    Posted By: WillInAberdeenShould be easy to log the inside and outside temperatures and energy consumption for the first month/year of occupancy and compare (energy/DeltaT) against a legal standard?


    Posted By: djhThe problem there is the users.


    Both true - there are undoubtedly a lot of non performing houses out there (due to poor fabric) but looking out of the window and seeing our neighbour's patio doors open all day suggests that it's hard pin down the specific cause (i.e. user or poor build).
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