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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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    • CommentAuthorbogal2
    • CommentTimeJun 24th 2021
     
    Theres a lot of old stone houses in the uk which, I agree, look really nice but are often really difficult to insulate to a reasonable standard. I realise there's been some great retrofits such as the GBS cre8 barn but a lot of old stone cottages have 500mm walls and don't have room for 250mm of internal insulation and if they're in a conservation area or NP can't be externally insulated. Should we be rebuilding them from the ground with stone cladding or just completely from scratch?
  1.  
    Neither in my opinion. We should be normalising external insulation as an aesthetic (and improving the offer), focussing on airtightness and ventilation, and removing the VAT imbalance between retrofit and new build too.

    There's a hell of a lot of embodied carbon in the existing stock, which we don't need to be displacing with another shoddy new building, often just as leaky and just as small.

    With permitted development as lax as it is currently, they've just approved a literal greenhouse near me to be converted to residential. That sure won't be well insulated and the demolition of hard to heat dwellings will just displace the same fuel-poor residents to these new office/industrial conversions where they'll struggle in the same way. Meanwhile the shiny new houses built on their old ones will be twice as expensive and probably only marginally more thermally efficient.

    I get where you are coming from, but there are bigger things to fix first.
  2.  
    Even if it were a good idea it's not doable: the UK building industry is unable to build enough new housing stock to keep up with demand, nevermind having capacity to replace existing homes at the same time.

    Well designed housing needs to conserve/enhance both "Natural Capital" (climate, biodiversity, green space) and "Social Capital" (communities, history, aesthetics) and "Financial Capital" (affordability, resources, deliverability). If any developer tells you they can only manage one or two of those, not all three, then they are not doing their job well enough, ask yourself why not!

    Fortunately we are about ten years away from zero-carbon and zero-guilt electricity in the UK, when the insulation you mentioned will become redundant (environmentally). Already, if you include 250mm of some insulations in a building, you will do more damage from the embodied emissions of manufacturing that insulation, than it will save in its lifetime.

    In twenty years time, the next generation will look back on the people who trashed stone houses in the name of energy efficiency, the same way as we look back on the pebble-dashers and cement-render vandals of the 20th century!


    So don't worry about the stone houses - just lag the lofts and floorboards, fix the drafts, and switch to electric/heatpump heating asap!
  3.  
    Good thoughts. I just did a presentation to a Carbon reduction group in a National Park last week, and the starting-point was an acceptance that, as it stands at present, a large proportion of the (stone) houses in the NP will not get EWI due to the views of the NP Planners. As a side-issue (but related) it is interesting to note that in some areas where stone building is typical *some houses were built of poor-quality stone and were always rendered* until someone came along and exposed the lovely stone that 'some ******' had covered up.... Then the fun begins. In one case the owner had got hold of historical pics to show that it was rendered just before 1900 (for pedants like me that's just before The Archers).
    • CommentAuthorowlman
    • CommentTimeJun 24th 2021
     
    "Should we be rebuilding them from the ground with stone cladding or just completely from scratch?"

    It's a brave politician who suggests that; a total non starter.
  4.  
    Posted By: bogal2 if they're in a conservation area or NP can't be externally insulated. Should we be rebuilding them from the ground

    Bogal, Nick, have you found examples where the planners would not allow EWI, but would allow the house to be demolished and replaced by an EWI'd house?

    Sounds weird, but I know weird things do happen in Planning..
  5.  
    ''Bogal, Nick, have you found examples where the planners would not allow EWI, but would allow the house to be demolished and replaced by an EWI'd house?
    ''

    No. The former, but not the latter, but that may well be because the people I have met who get the 'EWI - no' answer did not want to demolish.
    •  
      CommentAuthorfostertom
    • CommentTimeJun 24th 2021 edited
     
    Planner resistance to EWI will be against changed appearance, on Listed Buildings, or in National Parks, Conservation Areas etc, or sometimes on 'important' buildings that they possibly exceed their powers to vigourously protect as if they were one of the above -
    or elsewhere because the EWI thickness would encroach beyond the curtilage, onto public or neighbours' land.
    It's hard to imagine any other categories where EWI would be refused - anyone got examples?

    If it's about appearance, the planners will rarely allow demolition either.
    So prob the only way EWI would be refused, only to allow a new EWI'd building in its place, would be the curtilage case.

    EWI isn't expressly Permitted Development, in GDPO 2015 https://www.legislation.gov.uk/uksi/2015/596/made but this is clarified on p32 of Permitted development rights for householders: technical guidance https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/830643/190910_Tech_Guide_for_publishing.pdf :

    "Solid Wall Insulation The installation of solid wall insulation constitutes an improvement rather than an enlargement or extension to the house and is not caught by the provisions of (e), (f), (g), (h) and (j) [of A.1]."

    Not a lot of people know that!
    • CommentAuthorbogal2
    • CommentTimeJun 24th 2021
     
    Thanks for all your comments. So can you really put 200mm EWI on a 500mm stone-walled house? Does the wall thickness not become excessive aesthetically and practically? Has anyone done this? Ive looked at stone houses recently to buy and wondered if this was possible. Thanks for all your advice. I can imagine if it was an idyllic semi your neighbour might have something to say!
    •  
      CommentAuthorfostertom
    • CommentTimeJun 24th 2021
     
    EWI will change the appearance - it needs to be designed and drawn out. EWI can be a great way to re-style an ugly house, or even a change to a handsome house that still looks handsome. Things can be altered. The windows will be moved outboard - choice of style, mullions, glazing bars, detail, cill type. The easiest is to raise or lower the cill height; alterations to jambs, head, width, relocation is easier than if it the masonry had to be detailed to be waterproof and weather-durable - the EWI render will now take care of that. You'll prob be extending the eaves/verges - more styling opportunity - the eaves will end up lower, while the length of the facade gets longer by 2x200mm - so proportions can be played with. Get an architect - one who understands old buildings!
    • CommentAuthorvord
    • CommentTimeJun 24th 2021
     
    I live next door to a new build.The new build was built within the last 10 years and was signed off to all the latest standards. I'm in a house dating from 1600ish and extended a lot. Most things have been done badly along the way. But my energy bills are lower than the new build.

    Logically my house should be knocked down and rebuilt as we can completely ignore the energy involved in doing that.

    Or should the house next door be knocked down?
    • CommentAuthorJonti
    • CommentTimeJun 24th 2021
     
    Posted By: vord

    Or should the house next door be knocked down?


    With the standard of new build from many of the big construction companies it will probably fall down on its own :bigsmile:
    • CommentAuthorjms452
    • CommentTimeJun 24th 2021
     
    Posted By: Doubting_ThomasNeither in my opinion. We should be normalising external insulation as an aesthetic (and improving the offer), focussing on airtightness and ventilation, and removing the VAT imbalance between retrofit and new build too.

    There's a hell of a lot of embodied carbon in the existing stock, which we don't need to be displacing with another shoddy new building, often just as leaky and just as small.

    +1

    Posted By: WillInAberdeenIn twenty years time, the next generation will look back on the people who trashed stone houses in the name of energy efficiency, the same way as we look back on the pebble-dashers and cement-render vandals of the 20th century!

    +1

    Conflicted +1s!

    On one hand we don't need to EWI listed monuments
    While on the other this can't be a get out of jail free for anyone with a period feature (or we won't have zero carbon electricity in ten years due to the demand of all the old housing stock). Does the change to external appearance mean that even a ASHP box trashes the aesthetics of a period property?

    So the question is where the line is drawn & what's acceptable on a period property?
    • CommentAuthorvord
    • CommentTimeJun 25th 2021
     
    <blockquote><cite>Posted By: Jonti</cite><blockquote><cite>Posted By: vord</cite>

    Or should the house next door be knocked down?</blockquote>

    With the standard of new build from many of the big construction companies it will probably fall down on its own<img src="/newforum/extensions/Vanillacons/smilies/standard/bigsmile.gif" alt=":bigsmile:" title=":bigsmile:"></img></blockquote>

    It' will stand for less than 100 years before it gets too expensive to fix and will be replaced by another new house. I don't understand why the energy expended in new construction is not accounted for in any way.

    That energy is never accounted for. I suspect in the long term my really old house that is currently more energy efficient than the new builds might have something going for it in environmentally friendly terms. As always I have to mention I am a really bad person these days because I don't agree with mainstream thinking.
    • CommentAuthorjms452
    • CommentTimeJun 25th 2021
     
    Posted By: vordAs always I have to mention I am a really bad person these days because I don't agree with mainstream thinking.


    GBF is one of the least mainstream communities I'm aware of. Generally well informed and respectful too :bigsmile:
    •  
      CommentAuthordjh
    • CommentTimeJun 25th 2021
     
    Posted By: vordI don't understand why the energy expended in new construction is not accounted for in any way.

    It is if anybody bothers doing an LCA. But the general view until fairly recently has been that operational energy use is more important, so not many have been done. It's only recently that operational energy has dropped so far, and shorter lifetimes have been assumed for buildings, so the balance has changed somewhat and its now considered reasonable to do a comparison. But I think in general people still view practicality and appearance of their chosen approach more important than energy minimisation. :(
    • CommentAuthortony
    • CommentTimeJun 26th 2021
     
    I like the economics of street or district scale action rather than piecemeal approach

    I like energy use reduction and energy minimisation see MINERGIE

    There are too many and too large conservation areas and these have negative impacts and are and will become areas of dereliction
  6.  
    Posted By: tonyI like energy use reduction and energy minimisation see MINERGIE

    There are too many and too large conservation areas and these have negative impacts and are and will become areas of dereliction

    The MINERGIE seems to be another sort of pasive house standard and a quote from Wikipedia (so it must true??)
    "Certification
    Certification is done on the basis of planning values and thus offers no guarantee that these values are actually met."
    So again you will have the gulf between as planned and as built. I am not against it as such but another standard that addresses the plan rather than the actual IMO doesn't help that much.

    As the grid gets greener the emphasis will move from energy reduction to affordability, that is e.g. EWI has for some time (if not always) has had a ROI that makes no sense to install EWI other than for environmental reasons and with the increasing sustainable energy production the environmental driver goes away therefore the need to destroy the old hard to heat houses also goes away, or at least changes from environmentally damaging to affordability.

    The increasing number of conservation areas I don't think will create (too many) areas of dereliction but will IMO restrict the number of people who can afford to buy into them and thus exacerbate the housing issue. Listing buildings has a similar impact and with listing comes expense. Over here I have seen a couple of listed buildings abandoned to become derelict because the authorities would not allow affordable repairs, insisting things being done as original, and the owners, not being able to afford the demands, let the building decay into rubble. This makes no sense to me. (one of the plots, once the building went beyond repair was sold and PP obtained for clearance and rebuild with a modern structure).

    So to get back to the thread subject - no I don't think the old difficult to heat houses should be knocked down and the greener the energy production becomes the less the old houses impact the environment - people just have to be able to afford to live in them.
    • CommentAuthortony
    • CommentTimeJun 26th 2021
     
    But should people be allowed to waste energy in that way?
  7.  
    Define wasted energy. Energy used to keep a house habitable is not IMO wasted energy. If the environmental and financial cost of the energy is less than the cost of making the house more efficient then this is not a waste as the alternative - knock it down and spend more environmental cost replacing it would not make sense, especially as the replacement will also need energy to make it habitable. Yes you can make low energy houses but too often low energy houses are in name only and as the grid becomes greener the environmental cost of keeping old housing stock (or even badly built new housing stock) becomes less and less of an environmental issue, just a financial one.
    •  
      CommentAuthordjh
    • CommentTimeJun 26th 2021
     
    Posted By: Peter_in_HungaryDefine wasted energy.

    That's a very good question. And it depends how you 'define' 'energy' in this context. Because the carbon cost (whatever that is!) is also important. There's an unhelpful disconnect here between people who think energy should be saved (amongst whom I would broadly consider myself) and those who think that there are no energy constraints and there is a readily available supply of as much renewable energy as is required so we simply need a pricing mechanism to ensure its availability. But if there are constraints on the availability of renewable energy, then some form of energy demand limation becomes relevant.

    Plus in your hypothetical case, you need to decide whether you really mean energy or some broader concept involving carbon cost. Whatever that is!
    • CommentAuthorJonti
    • CommentTimeJun 26th 2021
     
    Posted By: Peter_in_Hungary
    The MINERGIE seems to be another sort of pasive house standard and a quote from Wikipedia (so it must true??)
    "Certification
    Certification is done on the basis of planning values and thus offers no guarantee that these values are actually met."


    I first came across MINERGIE in Switzerland about 15 years ago. It certainly worked well out there but maybe that was because the quality of build was very high which was maybe because there was a proper control made at each stage of the build. If new buildings in the UK simply met the present standards in reality that they do on paper it would be much better.
  8.  
    There's also a 'net present value' effect becoming apparent. Energy and materials that are consumed today, are more carbon intensive than equivalent energy and materials will be in a few years time. So it is becoming more important to conserve energy and materials today, rather than 'invest' in materials you hope will save energy into the future.

    For example, a few years ago it seemed sensible to manufacture a thick polystyrene and concrete slab to go under our then house, because it would save many years of carbon emissions. Today I am not sure it would be a good idea, because by the time it has paid back the embodied emissions of manufacturing, the heat it would be saving would already be carbon-free.

    Standards such as Passivhaus and Minergy are presumably going to have to be revised, so they recognise the carbon embodied in the building in balance with the carbon savings from low heating. They will need to encourage low-embodied-carbon design such as timber walls and floors, instead of cement and polystyrene slabs and block walls.
    •  
      CommentAuthordjh
    • CommentTimeJun 26th 2021 edited
     
    I agree with Peter & Jon that it is vitally important that buildings are tested and measured as built rather than as designed. That is a fundamental difference between Passivhaus and either SAP or Minergie (even Minergie-P, which is what we're talking about). Switzerland may well have a more 'traditional' sense of quality of work that means their buildings are closer to design than the rubbish here in the UK. But that's a lucky accident for them, not a purposeful resolution. I don't know, incidentally, whether there is a Swiss requirement for Minergie-P or just for Minergie; does anybody happen to know?

    PH has already considered embodied anergy to some degree. One view is published at https://passipedia.org/basics/energy_and_ecology/embodied_energy_and_the_passive_house_standard and that assesses embodied versus operational energy use.

    It's true that concrete slabs involve a fair degree of embodied energy, although there has been increased use of GGBS etc to reduce this. The costs and complexity associated with a suspended timber floor on piles, plus the inadvisability of using organic insulation underfloor, were what drove us away from that solution. Perhaps things have changed, but as with the plumbing it was practicality that drove us.

    But again, I point out that it's not just a question of operational energy being carbon free, it also has to be available in the quantities required. And my present understanding is that the supply is going to be overly restricted for quite some time to come. So I still tend to support the conservation of operational energy where possible. We still need energy to be cheap enough for everybody to buy the quantity they nee.
  9.  
    All true, and as you mentioned, its not embodied or operational energy that matter - it's embodied or operational carbon. A house built today will embody a certain amount of carbon, depending what it is built from, and will consume energy throughout its lifetime, but that energy usage will be carbon based for only a small part of that lifetime - nothing like the 80 years considered in that article.

    The CCC's supporting research for the 6th carbon budget includes an analysis of low-carbon electricity supply vs demand. They expect carbon intensity will take another step down around 2025 , but it will be 2030-35 before all electricity is low-carbon, based on how quickly supply can catch up with increasing demand. https://www.theccc.org.uk/wp-content/uploads/2020/12/Sector-summary-Electricity-generation.pdf

    The trick now is to build and refurbish houses in ways such that they can repay their embodied carbon within that time frame, otherwise they will never get chance to pay it back.

    Incidentally they also analyse the cost of supplying low carbon electricity and found it should cost broadly the same as at present, or a little less.
      Screenshot_20210420-231522.png
    • CommentAuthorMike1
    • CommentTimeJun 27th 2021 edited
     
    Posted By: WillInAberdeenThe trick now is to build and refurbish houses in ways such that they can repay their embodied carbon within that time frame [by 2030-35], otherwise they will never get chance to pay it back.

    That would be a good trick, and raises a couple of interesting hypothetical questions:
    Would it be possible to achieve that on a mass scale?
    Should all 'non essential' construction projects that can't achieve that - at a guess, right now, the majority of construction projects across the industrialised world - be put on hold until they can meet a strict embodied carbon payback time?*

    Of course once we have only decarbonised materials to work with - including zero carbon steel and concrete - that will also change the calculations, just as the more imminent prospect of zero-carbon electricity is starting to do now.

    *in these circumstance I guess the industry could be redeployed to work on a vast expansion of green energy generation projects...
    • CommentAuthorJonti
    • CommentTimeJun 27th 2021 edited
     
    Posted By: djhI agree with Peter & Jon that it is vitally important that buildings are tested and measured as built rather than as designed. That is a fundamental difference between Passivhaus and either SAP or Minergie (even Minergie-P, which is what we're talking about). Switzerland may well have a more 'traditional' sense of quality of work that means their buildings are closer to design than the rubbish here in the UK. But that's a lucky accident for them, not a purposeful resolution. I don't know, incidentally, whether there is a Swiss requirement for Minergie-P or just for Minergie; does anybody happen to know?



    Maybe I am misunderstanding you but the high quality of build the Swiss system creates is no 'lucky accident' as you put it but down to a whole system that is created to maintain high standards. A majority of school leavers go into an apprenticeship which are properly funded and monitored by the state. In addition, most construction companies only work within their local area and rely on having a good reputation in order to get work. Finally, builds are checked for compliance at every stage.

    Here in the UK we have worthless apprenticeships, large building companies who put profit before quality in the classic 'botch it and scarper' way of working and a complete absence on control. We need to stop trying to patch it with sticking plasters or looking for that 'one change' that will suddenly turn it around. The truth is we have a terrible system which produces a very poor product at highly inflated prices.

    To your question about if there is a requirement for MINERGIE(P) having read their website it appears it is a standard of build which if reached a certificate can be acquired so potential owners know what standard of energy efficiency the building has. It is recognised by all the counties in Switzerland and by the federal government as well. It is however not a required standard.
  10.  
    Just veering back to the OT:

    I haven't understood what the problem is with conservation areas?

    My parents' terraced house is in a conservation area, which has not prevented them insulating their loft, fixing lots of drafts, and replacing their doors and windows sensitively. If funds allowed, they could EWI the back elevation including the thin-skinned kitchen/bathroom lean-to, insulate the ground floors, and IWI the front elevation, and heat their DHW electrically. That all would reduce their carbon footprint by ~80%. And/or they could install an ASHP round the back, which would have the same effect and get better by 2035. The 19thC terraced form is already a pretty efficient shape, compared to 21stC exec-boxes.

    What measures have people actually not been able to implement in a conservation area? Is it just EWI on one face of the building, and was IWI allowed instead?

    Appreciate that Listed Buildings are more difficult but they are a small% of the housing stock. My uncle's Listed terrace is in the same street and (with care and expense) he has been allowed a loft conversion that meets BR standards.
    •  
      CommentAuthordjh
    • CommentTimeJun 27th 2021 edited
     
    Posted By: WillInAberdeenThe trick now is to build and refurbish houses in ways such that they can repay their embodied carbon within that time frame, otherwise they will never get chance to pay it back.

    It's the emissions that matter rather than the embodied carbon per se. There's no need for a CLT house to pay back the embodied carbon before electricity is decarbonised, to give just one example. Just as long as it doesn't burn down.
  11.  
    Very true - timber houses could be considered a form of carbon sequestration, so negative embodied carbon compared to other potential uses for that timber. Just so long as it doesn't burn down over a geological time scale...
   
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