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    • CommentAuthordelprado
    • CommentTimeApr 29th 2018
     
    In relation to building a house from scratch:

    What exactly is the point of an "essentially" zero heating building as opposed to a very low heating building?

    Or you could ask it another way, what is the point of building anything other than a passiv haus?

    Is there any counter argument to the idea that a house built from scratch should be anything other than a passiv haus? I've seen people mention "well designed houses", recognising that that passiv hauses are one such kind and intimating the are others without mentioning them. So what are they?
    •  
      CommentAuthorSteamyTea
    • CommentTimeApr 29th 2018
     
    All depends what you are trying to achieve.
    Passivhaus is not easy to achieve on small places.
    It is fairly easy to design a house that has neutral net energy imports, as long as you can stuff enough PV on the roof. Does depend on your plot tough.
    • CommentAuthortony
    • CommentTimeApr 29th 2018
     
    I would say to build very low energy use new houses every time. Not necessarily Passive Haus but with lower energy demand would be the best way to go.

    It was shown in Canad in 1978 that a house does not need a heating system if it is well insulated, with good windows and has hear recovery ventilation so long as the outside temperature does not fall regularly below -3C , not relavent to them as they get -30C every winter.

    Here we haven’t needed heating since then had we built properly insulated houses.

    In some Middle East countries the govt gives everyonr 500l of heating oil, insane when it would ne better to turn it into insulation and give that one year instead.
  1.  
    IMO the term Passive Haus has too much baggage.
    •  
      CommentAuthordjh
    • CommentTimeApr 29th 2018
     
    Posted By: delpradoWhat exactly is the point of an "essentially" zero heating building as opposed to a very low heating building?

    You'd have to precisely define what you meant by those terms for the question to have any meaning. And even then, it's quite likely the question would be akin to counting angels on the head of a pin. As ST hints at, it's easy to fudge a lot of definitions.

    In my opinion, the passivhaus standard is a very useful definition that accomplishes a number of things, including both the energy usage and also the quality of construction. But note that means a certified building. Building something to the principles or 'close' or even 'better' doesn't count IMHO unless it's actually certified. I'm sure there are lots of very happy people in uncertified buildings, but as a matter of policy it's a non-starter.
    •  
      CommentAuthorfostertom
    • CommentTimeApr 30th 2018
     
    By<blockquote><cite>Posted By: delprado</cite>"essentially" zero heating building</blockquote>is this reference to the European 'Nearly zero energy building' nZEB? http://bpie.eu/publication/principles-for-nearly-zero-energy-buildings/

    "While the [recast] Energy Performance of Buildings Directive (EPBD) requires that from 2020 all new buildings are nearly Zero-Energy Buildings (nZEBs), the proposed definition leaves a number of uncertainties"
  2.  
    imagine you ave a clean free heat source , then wasting time and money on insulation would be pointless.
    There's a counter argument , but since we haven't just currently or there doesnt appear one round the corner its not valid.
    Id presumed the idea of designing out heating or cooling was you'd not only have lower bills etc. youd never have any outlay to install or maintain it or change it as energy resources change
    •  
      CommentAuthorfostertom
    • CommentTimeApr 30th 2018 edited
     
    Posted By: jamesingramsince we haven't just currently or there doesnt appear one round the corner
    True, we haven't, but The Switch
    https://www.amazon.co.uk/Switch-solar-storage-means-cheap/dp/1781256357/ref=sr_1_1?ie=UTF8&qid=1525108744&sr=8-1&keywords=the+switch+chris+goodall
    gives much evidence that ever-cheaper (like, price of a phone) and multifold-efficient solar collection plus storage will become universal, at ever-increasing pace, whether grid connected or auronomous. At that point
    Posted By: jamesingramimagine you ave a clean free heat source , then wasting time and money on insulation would be pointless

    However, what would remain as good-practice, is PH's primary (they say) objective of year-round comfort (no downdraghts from less than 3G windows) and healthy air (MHRV) via airtightness. It's not just about insulation, CO2-saving and fuel bills.
    •  
      CommentAuthordjh
    • CommentTimeApr 30th 2018
     
    Posted By: jamesingramimagine you ave a clean free heat source

    My gut instinct is that this is impossible, especially when you take 'free' to also mean 'free of embodied energy' i.e. not using any energy to create it. But we've had talk of 'energy too cheap to meter' for donkey's years and we're no closer to it.
    • CommentAuthorTimSmall
    • CommentTimeApr 30th 2018 edited
     
    Weren't the Passivhaus standard levels chosen to minimise the lifetime cost of the building (i.e. (build + interest) + energy to run). i.e. it is possible to build a no-heating-required building, but it'd cost so much in Northern Europe that it's current uneconomic to do-so.

    The reason that Passivhaus isn't ubiquitous is a combination of "future discounting", and misaligned economic incentives (if you don't have to pay the bills for a house (because you're not going to live in it), then the economic incentive is to not build an energy efficient building).

    Posted By: fostertomefficient solar collection plus storage will become universal, at ever-increasing pace


    That's possible, but it's also possible that it'll plateau, or that the recent price decreases will slow.

    So whilst I hope it'll happen I wouldn't bet the farm on it.

    That having been said, solar PV (without storage) is now the cheapest form of energy generation in a sizeable proportion of the globe, and it certainly cheers me up when I find that the cost per kWh of solar record has been broken again e.g. recently about 3p/kWh for a 20 year contract in IIRC Peru (edit - Chile, with Mexico also receiving similarly cost-effective bids).

    Anyway, we've got to work out how to make PV cheap because otherwise we'll never get that Dyson Sphere built...
    • CommentAuthorTimSmall
    • CommentTimeApr 30th 2018
     
    • CommentAuthorBeau
    • CommentTimeApr 30th 2018 edited
     
    Worth remembering a passiv haus can use a fair bit of energy and still qualify http://www.greenbuilding.co.uk/GBF_Forum/discussion/11661/confused-by-passive-house-standards
    • CommentAuthorgravelld
    • CommentTimeMay 1st 2018
     
    Posted By: TimSmallThe reason that Passivhaus isn't ubiquitous is a combination of "future discounting", and misaligned economic incentives (if you don't have to pay the bills for a house (because you're not going to live in it), then the economic incentive is to not build an energy efficient building).
    For a broad enough definition of economics, this. Change the incentives, change the behaviour.
    •  
      CommentAuthorfostertom
    • CommentTimeMay 1st 2018
     
    Posted By: djhwe've had talk of 'energy too cheap to meter' for donkey's years and we're no closer to it
    True it's been promised (nuclear) and has not happened - but 'this time it's different', as are a great many things, all aspects of a new exponential created by the information revolution (you've heard all this!). More than ever, extrapolation of past wisdoms is no guide to the future.

    Posted By: djhespecially when you take 'free' to also mean 'free of embodied energy' i.e. not using any energy to create it
    I didn't actually say 'free' - but anyway that old (well, quite recently new) formulation is also blown away by 'ever-cheaper' solar. Solar can be evolved to be 'free' in terms of Environmental Impact, if not entirely in money terms.

    Embodied Energy is a reality-check that's useful in this still-fossil age but is only a v approx proxy for Environmental Impact (most widely and honestly assessed). Extraction/pollution/closed circle materials re-use, 'doing more with less' etc are the real criteria of Environmental Impact - Embodied Energy gets less important when snag-free truly Renewable energy is almost freely available.
    •  
      CommentAuthordjh
    • CommentTimeMay 1st 2018
     
    Posted By: BeauWorth remembering a passiv haus can use a fair bit of energy and still qualify

    I think you'll find you misunderstood the discussion if you still believe that.
    • CommentAuthorringi
    • CommentTimeMay 12th 2018
     
    Land cost and planning also come into it, as often going passive makes the rooms smaller, as the outside size of the home is fixed.
    •  
      CommentAuthorfostertom
    • CommentTime6 days ago
     
    Easily compensated by abandoning the universally-assumed need for a useless 3ft wide space-waste path along at least one (often two) boundaries. Build right on or as tight as poss to the boundary - amazing how spacious that makes even a tiny site seem, does wonders for the 'rootedness' and 'communityness' of the house, helps combat that miserable 'detached suburban scatter' could-be-anywhere look.
    • CommentAuthorbarney
    • CommentTime6 days ago
     
    And taken to a logical conclusion, build terraced houses, Tom ?

    Back to back with yards for drying washing would be a real good use of space.

    Not sure that does wonders for well being however

    Regards

    Barney
  3.  
    Posted By: fostertom...a useless 3ft wide space-waste path along at least one (often two) boundaries.

    That 3' path can be handy for the refuse bin(s), unless:

    a) You keep the bin(s) around the front.
    b) There is easy (enough for a bin collection to agree to use it) access to the back.
    c) You are willing to drag the bin through the house.
    •  
      CommentAuthorfostertom
    • CommentTime6 days ago edited
     
    Posted By: barneyAnd taken to a logical conclusion, build terraced houses, Tom ?
    Oh, horror! Nothing wrong with terrace houses, with or without mucky-wheelbarrow size garden(s) front and rear - depends on design quality - many excellent examples, often high priced.
    • CommentAuthorbarney
    • CommentTime6 days ago
     
    I wasn't suggesting there was anything wrong with terraced houses, Tom

    Like everything it needs a balance - as I pointed out.

    Personally speaking, I wish we built many more of them instead of bloody city centre apartments complete with stack bonded blocks, glass balconies and endless cedar board and sto render facades. It's not as if we are short of land now, is it

    Regards

    Barney
    • CommentAuthorgyrogear
    • CommentTime5 days ago
     
    Posted By: fostertoma useless 3ft wide space-waste path along at least one (often two) boundaries.


    In my (French) town, it is either three meters minimum, or nothing at all...

    gg
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