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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.

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  1.  
    A client has a high-spec timber-framed house with a Predicted Energy Assessment (PEA _ provisional off-plan EPC) of 85 (B). U values are around 0.12 (except windows!) and 1st air-tightness test was about 2.3m3/m2/hr. Client was hoping for an A. I haven't been a SAP assessor since the old 1-100 scale, so I don't even know if it is possible to get an A on fabric alone. Does anyone know?
    • CommentAuthorringi
    • CommentTimeOct 31st 2015
     
    What about flue get heat recover on the gas boiler?
  2.  
    Hmm. Don't know. Do you mean something like the Zenex gas-Saver (which I think Alpha took over)?
    • CommentAuthorringi
    • CommentTimeNov 1st 2015
     
    Posted By: Nick ParsonsHmm. Don't know. Do you mean something like the Zenex gas-Saver (which I think Alpha took over)?


    Yes, Alpha along with Baxi licance the design.
    • CommentAuthorDarylP
    • CommentTimeNov 2nd 2015
     
    Nick,

    ..the answer is YES (practicably....):wink:
    • CommentAuthorringi
    • CommentTimeNov 2nd 2015
     
    Shower heat recover also gets you some points, but is still very new.
    • CommentAuthorJeff B
    • CommentTimeNov 3rd 2015
     
    Don't think about a wood pellet boiler then. You'll end up with a D rating!
    • CommentAuthorteacosy
    • CommentTimeNov 5th 2015
     
    Don't know if it helps but we've just completed our 'as built' SAP and come out with an 'A' energy efficient rating [94].
    U values: walls 0.14, roof 0.17, floor 0.11, windows/doors 0.95
    Air permeability test 0.8

    asked the assessor how the result would have changed if we'd gone for oil boiler in place of ASHP (no mains gas) and without 4kw PV panel array, everything else the same. Would have got a B rating [85].

    Assessor's comments: "although you would get the FEE target, you would NOT get overall compliance, so would fail the SAP on Carbon emissions."
    • CommentAuthorJeff B
    • CommentTimeNov 5th 2015 edited
     
    Posted By: teacosyDon't know if it helps but we've just completed our 'as built' SAP and come out with an 'A' energy efficient rating [94].
    U values: walls 0.14, roof 0.17, floor 0.11, windows/doors 0.95
    Air permeability test 0.8

    asked the assessor how the result would have changed if we'd gone for oil boiler in place of ASHP (no mains gas) and without 4kw PV panel array, everything else the same. Would have got a B rating [85].

    Assessor's comments: "although you would get the FEE target, you would NOT get overall compliance, so would fail the SAP on Carbon emissions."


    I would have got a B rating if I'd reverted back to an oil boiler instead of continuing with my wood pellet boiler! Instead we got a "D" because all wood pellet boilers are given a generic efficiency of 60% if I remember correctly. (Mine is actually 90%!).
  3.  
    Teacosy and JeffB, thanks for your posts. I think it's pretty much as I thought, that it's generally renewables and other bolt-on goodies which give an A.
    • CommentAuthorteacosy
    • CommentTimeNov 6th 2015
     
    I must admit I'd have felt a bit short-changed not to have got an 'A', so I can see where your client is coming from Nick.

    If anyone wants a Friday chuckle, here's what the EPC helpfully suggested I could do to improve my rating:
    "Actions you can take TO SAVE MONEY and make your home more efficient
    Recommended measures
    1. Solar water heating - indicative COST £4,000 - £6,000 - typical SAVINGS over 3 years £261 -> A96
    2. Wind turbine - indicative COST £15,000 - £25,000 - typical SAVINGS over 3 years £1,614 -> A108"

    I can see it's going to be so totally worth it I'm dusting off my cheque book and placing orders today!
    :bigsmile:
    •  
      CommentAuthorSteamyTea
    • CommentTimeNov 7th 2015
     
    Cost more to service the ST than it will save won't it. :wink:
  4.  
    Thanks too to Ringi and DarylP, and for the whispers.
    • CommentAuthorowlman
    • CommentTimeNov 9th 2015
     
    I hope I'm not hi-jacking your thread Nick, apologies in advance, but this seemed appropriate.

    Q. Apart from the kudos, and excluding RHI and house sale, is there any point in chasing a higher rating. When I was rated my house was "D", recent measures push it into "B", should I bother?
  5.  
    At the moment I think 99% of purchasers don't let the EPC influence their decision in any way.
    • CommentAuthorJeff B
    • CommentTimeNov 9th 2015
     
    Posted By: richardelliotAt the moment I think 99% of purchasers don't let the EPC influence their decision in any way.


    May be not today but who knows in the future when energy prices start climbing again? I suppose it all depends on how long you intend to live in your present property.
  6.  
    '' excluding RHI and house sale, is there any point in chasing a higher rating?''

    Except for FiT and curiosity, no! Re-submit it when you need to.
    • CommentAuthorEd Davies
    • CommentTimeNov 9th 2015
     
    You don't have to be able to outrun the bear: having a B rating where all the other similar houses around have Cs and Ds would win, surely? Particularly if the house is set up to allow renewable to be added easily - e.g., appropriate shape S facing roof not messed up by dormers, etc.
    • CommentAuthorgravelld
    • CommentTimeNov 9th 2015 edited
     
    There is some questionable research which suggests there is a link between higher prices and EPC bands: https://www.gov.uk/government/news/energy-saving-measures-boost-house-prices

    But it seems to me it's a very muddy picture, and anecdotally I don't see a lot of evidence for this. People want "character fireplaces" not air tightness.

    And as we know EPCs are crap anyway.
    • CommentAuthorsnyggapa
    • CommentTimeNov 9th 2015
     
    Reluctantly agree, I would be in the minority that I would look at an EPC in relation to a house purchase, but it would not be a deciding factor.

    Sadly, I don't think there is the political will to make energy prices expensive enough to start adjusting people's behaviour
  7.  
    Posted By: gravelldBut it seems to me it's a very muddy picture, and anecdotally I don't see a lot of evidence for this. People want "character fireplaces" not air tightness.


    I agree. I think most people are swayed by location and a house having a nice kitchen (or whatever else is on their personal list of requirements).

    Some people might be persuaded to pay a bit more if you showed them a relaible income stream from FITs or that the energy bills had a track record of being very low. But I think this would need to be a small minority and they'd want to the see the numbers, not an EPC certificate.
    •  
      CommentAuthordjh
    • CommentTimeNov 9th 2015
     
    Posted By: richardelliotSome people might be persuaded to pay a bit more if you showed them a relaible income stream from FITs or that the energy bills had a track record of being very low. But I think this would need to be a small minority and they'd want to the see the numbers, not an EPC certificate.

    Exactly, and some others would be put off by worries of being suffocated if the MVHR broke down ...
    • CommentAuthorgravelld
    • CommentTimeNov 9th 2015
     
    Yeah, air tightness needs rebranding.
    • CommentAuthorowlman
    • CommentTimeNov 10th 2015
     
    Posted By: djh
    Posted By: richardelliotSome people might be persuaded to pay a bit more if you showed them a relaible income stream from FITs or that the energy bills had a track record of being very low. But I think this would need to be a small minority and they'd want to the see the numbers, not an EPC certificate.

    Exactly, and some others would be put off by worries of being suffocated if the MVHR broke
    down ...



    Posted By: gravelldYeah, air tightness needs rebranding.



    True, most of the people I know quite simply don't want to live in what they see as hermetically sealed boxes.
  8.  
    Posted By: owlmanTrue, most of the people I know quite simply don't want to live in what they see as hermetically sealed boxes.


    Totally agree. The concept of not opening windows is very alien to most people.

    If I ever sell my house (and if we get a good air tightness score!) I don't think I'd ever advertise it as being airtight or having an MVHR system as it would put most people off. The best marketing terms would probably be things like 'warm', 'cosy', 'low running costs' etc....

    If there is some one interested in air tightness I think they'd probably ask and you could explain it to them then.
    • CommentAuthorgravelld
    • CommentTimeNov 10th 2015
     
    Definitely. That's why I think we should all rebrand to high performance housing rather than the dreaded "eco homes".
    • CommentAuthorDarylP
    • CommentTimeNov 10th 2015 edited
     
    ... that's what the EPC is designed to do:bigsmile::bigsmile:
    Hence the rating system A-G, with the coloured bars, in line with ratings on light-bulbs, electrical appliances etc etc

    The issue is people buying homes do not use 'logic', as when they buy appliances, cars etc etc, but 'kerb appeal' , and location location location... :wink:
    • CommentAuthorringi
    • CommentTimeNov 10th 2015
     
    location location location is key,

    There are not many homes on the market at any given time, once you have decided on the size of home. Then there are schools to consider.

    But let’s get back to being green; having a 20 minutes drive to work from a C rated home, instead of a 40 minute drive from a B rated home is likely to be a good trade off. Event better if you can walk to the station from the C rated home.
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