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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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    • CommentAuthorMike1
    • CommentTimeJun 27th 2021 edited
     
    Posted By: djhSwitzerland 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.

    I've just been taking a look and it seems that Swiss building standards may not be particularly good - "initial findings [of a report] suggesting [a] 30-300 percent gap measured compared to predicted energy performance in residential buildings" (quote from 'Mapping of Existing Energy Efficiency Standards and Technologies in Buildings in the UNECE Region, 2018).

    Maybe it's just that, as in the UK, people who care enough about building quality to invest in schemes such as Minergie, end up with well-performing buildings.

    Also interesting: Why most Swiss buildings are environmentally inefficient
    https://www.swissinfo.ch/eng/climate-crisis_why-it-may-take-100-years-to-renovate-every-building-in-switzerland/45481906#
    •  
      CommentAuthordjh
    • CommentTimeJun 27th 2021
     
    Posted By: WillInAberdeenVery 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...

    Well, it only has to last as long as a tree that died in the forest would, or until the climate crisis is past and carbon-free electricity is too cheap to meter so CCS is reasonably doable. :devil:
    • CommentAuthorJonti
    • CommentTimeJun 28th 2021
     
    Posted By: Mike1
    I've just been taking a look and it seems that Swiss building standards may not be particularly good


    Mike1,

    can you define what you mean by 'Swiss building standards'. It seems to me the report says that much of the building stock is pre 1980's, is heated by oil which is as standard there as gas is here in the UK and that many home owners are hesitant to spend tens of thousands of Swiss francs on renovations that won't see a return for several decades. I do not see anywhere in the report where the quality of construction is criticised nor that the building regulations are substandard. Maybe the problem is more that because the construction quality is so high buildings are able to get by without renovations for much longer.
    • CommentAuthorMike1
    • CommentTimeJun 28th 2021
     
    Jonti, there are two reports - the quote is from 'Mapping of Existing Energy Efficiency Standards and Technologies in Buildings in the UNECE Region, 2018'
  1.  
    IMO the energy use of the old difficult to heat houses - and for that matter the newer sub-standard houses comes down to 2 issues.
    1 the carbon footprint of the heating vs. the carbon foot print of any upgrade and the length of the carbon pay back of any upgrade.
    2 the ROI of any insulation upgrade against the cost of the used energy.

    Most people I suspect will be looking at the 2nd issue and have little thought for the first. Loft insulation is a bit of a no brainer whilst EWI hasn't made economic sense (e.g. ROI in excess of 25 years) for some time.

    For issue 1 as the grid becomes greener the carbon foot print payback time of any upgrade gets further into the distance to the point that upgrading would not make environmental sense.
    • CommentAuthorJonti
    • CommentTimeJun 29th 2021
     
    Posted By: Mike1Jonti, there are two reports - the quote is from 'Mapping of Existing Energy Efficiency Standards and Technologies in Buildings in the UNECE Region, 2018'


    Thanks Mike,

    I missed the second report but have now found it. I haven't had time to read more than the just the introduction of the report but if I do I will read more though it is quite a volume and I suspect some/most will be above my pay grade :shamed:

    I am still not sure as to what you what you mean by 'Swiss building standards' so if you could clear that up it would help.
    • CommentAuthorMike1
    • CommentTimeJun 29th 2021
     
    I've no personal knowledge of the Swiss market, but since the above mentioned report is published by a United Nations body, the quote is presumably substantiated. You'd need to trace back to the original source for the full details :)
    • CommentAuthorJonti
    • CommentTimeJun 29th 2021
     
    Posted By: Mike1I've no personal knowledge of the Swiss market, but since the above mentioned report is published by a United Nations body, the quote is presumably substantiated. You'd need to trace back to the original source for the full details :)


    Mike,

    if I find the time I will have a root around for it but I think I will reserve drawing any conclusions on the intro to the report. I take it that as you have failed to address the question I asked (twice) that you are as clueless about what you meant by your comment as I am :wink:
    • CommentAuthoran02ew
    • CommentTimeJun 30th 2021
     
    Sorry im late on this one, but in answer to the OP, IMO if the current owners is to prepared to invest in old housing stock (regardless of grades or titles) they should be allowed to demolish and rebuild. if we need to pay homage to what was there once, Take a picture!
    • CommentAuthoran02ew
    • CommentTimeJun 30th 2021
     
    If it hasn’t been mentioned already the 20%VAT saving when a building is flattened and rebuilt is another heavy argument. Maybe if there was a similar saving for old housing being extensively upgraded(supercharged) this would encourage a more sensitive approach.
    • CommentAuthorrevor
    • CommentTimeJun 30th 2021
     
    Totally agree as someone who has spent more on building around an old building than what would have been new, never mind the VAT saving which would have gone a long way towards the cost. I would guess per sq.M factoring in the VAT our house has cost 30% extra. On hindsight would have been better finding a plot and starting anew. We were influenced by the fact that 20 years earlier PP was granted to demolish and build a new house but what we had not realised was the rules had changed and despite being of no architectural merit because the building was habitable it could not be demolished.
    •  
      CommentAuthorfostertom
    • CommentTimeJun 30th 2021
     
    Posted By: an02ewMaybe if there was a similar saving for old housing being extensively upgraded(supercharged) this would encourage a more sensitive approach
    VAT is reduced to 5% for energy-efficiency work to upgrade existing buildings (houses anyway - not sure).

    I have phone conversations, for which they gave me case numbers to quote in future, to confirm that this is intended to be much more 'generous' than it appears from reading the VAT booklet. The definition of energy-efficiency work is broad - it includes most things that were necessary to prepare for or facilitate the work - demolition, scaffolding, making good etc. The only anomally is that replacement windows are excluded. The work has to be carried out in one operation by a VAT registered builder - no use to self-builders. The work can be part of a larger building contract that doesn't qualify as energy-efficiency, but the energy-efficiency work has to be clearly separated, for VAT, in the builder's invoice(s) to client. Of course it's up to the builder to get HMRC's agreement with the separation and calcs. I've had a builder (and his accountant) refuse to do this, refuse to contact HMRC quoting my phone call case nos. Actually we terminated that builder's contract - big ruction!

    Andy, we did this successfully on a couple of contracts.
    • CommentAuthorGarethC
    • CommentTimeJul 1st 2021
     
    Morning all,

    Does anyone know where I can find historic hourly data for any variable electricity tariff?

    As mentioned in another thread, for old, hard to insulate properties, I'm trying to work out:

    1. The average (over the year) achievable carbon intensity of heating with a modern storage heater with smart controls (using electricity at times of lowest cost and carbon intensity).

    I've found half hourly grid carbon intensity allowing me to do this for the UK as a whole (be very interesting to do for regions with greener electricity such as Scotland). First figures suggest that you could heat with lower emissions than via a high efficiency gas boiler (assuming 200g/kWh). Will report back on by how much, but this should only improve.

    2. What the running cost would look like. But I can't find historic data on variable tariff pricing. Any ideas? Realise I'll need to estimate real life efficiencies etc.

    Once I've done this, I'll try to estimate capital costs. As mentioned, I suspect for the kind of properties we're talking about it might be a better option than heat pumps. As soon as you have to go to under floor heating for your emitters, which seems common, I just think the installation costs of heat pumps are a killer.
    • CommentAuthoran02ew
    • CommentTimeJul 1st 2021
     
    Posted By: fostertomVAT is reduced to 5% for energy-efficiency work to upgrade existing buildings


    yes, to a point. but really only covers things like EWI (not evan sure about IWI) loft insulation and bolt-on power generation (solar, heat pumps etc) it doesnt cover MVHR, new windows, airtightness measures, general internal or external alteration or any technical/architectural design work.

    i advise that if the estimated build cost is above 150K(30K of VAT) and involves the removal of the roof than it worth considering the knock down and rebuild.
    • CommentAuthorphiledge
    • CommentTimeJul 1st 2021
     
    Posted By: an02ew

    i advise that if the estimated build cost is above 150K(30K of VAT) and involves the removal of the roof than it worth considering the knock down and rebuild.


    Is that advice just from a commercial point of veiw and not considering the embodied emissions in building from new? Theres also the environmental cost of disposing of what may have been a perfectly good house but for higher energy consumption than the new one.

    I dont know if figures exist comparing total emissions from a new build over an eco refurbished older house?
    • CommentAuthoran02ew
    • CommentTimeJul 1st 2021
     
    It has worked well previously with 1960/70 bungalow, the walls were crushed for paths/patios and driveway. The roof tile were sold. The metal and cable was weighed in as scrap. there wasnt much that had to go to landfill.
    In that instance the planned remodel would have easily taken as long and been as extenive and the new build as the only thing that remaind were the old (poorly built) cavity walls that were deffinatly not worth the plus 30K VAT they inforced. once removed we were left with a nice usable oversite that allowed a clean build platform even in the winter.
  2.  
    Hi Gareth C, I found we have to be careful where we get grid intensity figures from. Many of the popular websites are based only on the generation figures for the national Transmission system, and so miss out all of the solar and a chunk of the wind generators which are connected to the Distribution systems, for which data are harder to obtain. Missing out these makes their intensity figures look too high.

    The Drax Energy Insights site seems to include estimates for embedded solar and wind and seems to be transparent about their methodology. I haven't found an easy way to download their data as spreadsheet etc.

    For Nov-Feb last winter they reported an average intensity of 186g/kWh, so an always-on electric fan heater is already better than a gas CH system environmentally.

    An electric heat or power storage heating system could presumably do much better, and if it includes a heatpump it is miles better than gas.

    As was mentioned a) this will only improve, but b) if everyone does this at once then it will delay the rate of improvement until the supply of renewable generation catches up, but c) even so that's no reason to delay, as some improvement now is better than none!

    So environmentally its better to insulate and pump heat and store heat, by 'the right amount' to enable as many homes to be electricity heated as soon as possible, without locking in too much embodied carbon from all that cement and polystyrene and plumbing... How much is 'the right amount'?!?

    If you knock down and replace a block/brick wall now, I think that causes more carbon than it will ever save through better insulation before heating is decarbonised. Maybe still ok if you replace with timber, though the case for that is getting weaker each year.
    • CommentAuthorSimonD
    • CommentTimeJul 1st 2021 edited
     
    Posted By: philedge
    I dont know if figures exist comparing total emissions from a new build over an eco refurbished older house?


    Here is an interesting paper where the authors look at this. It's rather inconclusive but nevertheless does provide some useful info. (https://discovery.ucl.ac.uk/id/eprint/1566963/1/Schwartz_Life_Cycle_Carbon_Footprint.pdf). It's unclear whether the refurbs are 'eco' mind you, as I'd suspect that members here would be inclined to go to greater lengths with a refurb.

    Its conclusion:

    The analsysis of refurbished and new residential buildings in the UK and Ireland(cases with geographic proximity and similar climatesand constructionmaterials)is illustrated in Figure 9b. Refurbished buildings seem to have a better performance than new ones,with an average LCCF of 3,500 (new) and 2,250 (refurbished) kgCO2/m2/50 years (n1=28, n2=26, p<0.05).While this trend is statistically significant, some new buildings still showed a better performance than the best refurbishments. Similarly, in this case, it is difficult to determine which alternative can be considered ‘better’.

    From a UK perspective, it references a study which concluded that "the worst 14% of the total stock should be replaced, while most existing buildings should be refurbished."

    One very interesting point made in this paper relates to how the use of district heating reduces life-cycle carbon footprint.

    Somewhere a while ago I came across a comparison of refurbing or newbuild to passivehaus house standards and the refurb edged it.

    From a slightly different perspective, I find myself uncomfortable about the seemingly singular approach used to consider house fabric upgrades, whether refurb or new build that is entirely built upon economic payback. For example, the question as to whether I'll ever get payback from insulating my home. I think this question is entirely the wrong way round and there are many other important considerations. For instance:

    Living in both Sweden and Switzerland, I never, ever experienced the need to turn the thermostat up in any of the houses or flats where I lived. The only country I've had to do this is the UK, in old sh*tty housing stock. As soon as we experience thermal discomfort, usually in the form of draughts, we whack up the thermostat to over compensate for that feeling. For me, the whole idea about upgrading my house from a thermal perspective is to provide a level of comfort where I enjoy to be. This doesn't necessarily come with an economic payback measure, but does mean the world to me in terms of a living environment. I've experience a lot of older houses that provide me with that comfortable living environment, a place that feels good.

    Other than the strange UK obsession with house equity, we typical don't buy a house by calculating payback, nor do we do so when we buy a car. Who installs a new kitchen and bathroom, calculating the payback? Isn't it then a little perverse that thermal upgrades are so determined? I some ways I think this market has lost the plot.

    My other discomfort is the way in which environmental considerations have been narrowed down to carbon footprint. I accept that this is important, but what disturbs me is that now in many instances environmental impact has become a synonym for carbon footprint without sufficient consideration of wider ecological impact. For instance, lack of consideration for the issues of battery recycling/waste, little consideration of the waste implication of solar panels, a huge number of which are about to be replaced (due in part to subsidy models) and which cost approx 10x as much to recycle than throw into landfill. There seems also to be little regard to the wider ecological impact of heat pumps and their constituent parts. Much of this seems to be perpetuate by the false proposition that renewable energy is somehow free - this is the same nonsense that has been peddled and supported by policy around the world that has hidden the the real-world cost of 'cheap' fossil fuels.

    For me there needs to be a much more systemic approach to how we go about managing 'green' implementation and as djh suggested, it puts me fairly and squarely into the camp of reducing consumption first.
    • CommentAuthorphiledge
    • CommentTimeJul 1st 2021
     
    Posted By: an02ewIt has worked well previously with 1960/70 bungalow,


    We were the exact opposite as we retained a 50's bungalow and extended partly around it and over the top of the existing. The existing structure had the 3" cavity filled and 400mm loft insulation added where there wasnt a second floor over the original bungalow. I dont beleive the existing parts that we retained will consume more energy for a very long time than if we'd knocked it down and rebuilt with all the embodied emissions in a new build together with a reduced energy consumption.

    Whilst its possible for an eco concious builder to demolish and salvage alot of materials, unless they are going to be reused as is, theres an emmisions cost to crushing brick, reprocessing scrap and dumping what cant be reprocessed. I dont know if representative stats exist that consider the whole demolition and rebuild emissions??
    •  
      CommentAuthordjh
    • CommentTimeJul 1st 2021
     
    GarethC asked: "Does anyone know where I can find historic hourly data for any variable electricity tariff?"

    Google says https://www.energy-stats.uk/download-historical-pricing-data/
    • CommentAuthorphiledge
    • CommentTimeJul 1st 2021
     
    Posted By: SimonD
    For me there needs to be a much more systemic approach to how we go about managing 'green' implementation.


    +1
  3.  
    Posted By: SimonDhttps://discovery.ucl.ac.uk/id/eprint/1566963/1/Schwartz_Life_Cycle_Carbon_Footprint.pdf

    Interesting - thanks!

    Looks like that was based on a database of case studies from about 2000-2010. Seems to me that the carbon impact of using energy for heating was much more significant back then (I was pretty focused on saving energy and never thought much about using materials).

    If the analysis were done on a forward-looking basis, based on forecast of the carbon intensity of energy throughout the lifetime of the building, would the conclusion be different?

    Looking again at the CCCs forecast (on previous page) perhaps two-thirds of the remaining carbon emissions from electricity, occur between now and 2025 when they note that many GW of planned wind farms will be completed. After that, intensity falls quickly. So for a building that will be completed in say 2022, there is more incentive to save heating than for one that would be completed in say 2024. I don't know if our building industry (building regs, training, product development) can adjust that quickly.

    The building industry is still driven by SAP 2012 which uses 519g/kWh for electricity, now massively too high, which discourages electric heating and over-rewards bolt-on PV, and doesn't consider the embodied carbon at all.
    • CommentAuthorMike1
    • CommentTimeJul 1st 2021 edited
     
    Thinking about this, the concept of embodied carbon may have some timescale-related problems.

    If a tree is felled now, for example, it stops absorbing carbon, and it may well be 30 years before the replacement is able to start absorbing an equivalent amount, and longer before the new tree has paid back the carbon deficit incurred. If the overall target is to go carbon neutral by 2050, in some circumstances and for some classes of products, it may therefore be better to avoid wood. I guess straw and hemp would come out of such an evaluation well, as they're renewed annually, but maybe some conventional building products may make the grade (if their embodied carbon is repaid through reduced heating emissions before electricity goes carbon-neutral, for example). Has anyone seen any calculations on this?
    • CommentAuthorSimonD
    • CommentTimeJul 2nd 2021
     
    Posted By: WillInAberdeen

    Looking again at the CCCs forecast (on previous page) perhaps two-thirds of the remaining carbon emissions from electricity, occur between now and 2025 After that, intensity falls quickly.



    Posted By: Mike1Thinking about this, the concept of embodied carbon may have some timescale-related problems.

    If a tree is felled now, for example, it stops absorbing carbon, and it may well be 30 years before the replacement is able to start absorbing an equivalent amount, and longer before the new tree has paid back the carbon deficit incurred. If the overall target is to go carbon neutral by 2050, in some circumstances and for some classes of products, it may therefore be better to avoid wood. I guess straw and hemp would come out of such an evaluation well, as they're renewed annually, but maybe some conventional building products may make the grade (if their embodied carbon is repaid through reduced heating emissions before electricity goes carbon-neutral, for example). Has anyone seen any calculations on this?


    I think these points come together in terms of another potential hiccup in our net-zero strategy. I know things have changed rapidly in the last few years but in 2017 biomass was the biggest source of renewable energy (ca 40%) in the UK and even in the CCC's budget it's estimated to make up to 15% by 2050.

    Biomass is already causing net carbon emissions in counties that where carbon negative. This is primarily due to mass demand across Europe. Drax even imports massive amounts of wood pellets from its forests in North America to fuel the UK. And the CCC is suggesting more subsidies to support this market.

    For energy production I don't think biomass should play such a potentially large role where solar - here I include wind/tidal/direct solar - make so much more sense as it doesn't mean competing demand in a way that crops do.

    The CCC also points to timber as a key resource for reducing carbon production in construction, but with global demand increasing it's already seeing problems in sustainability.

    The CCC seems to think we can develop our national bio resources by 2050, in part thanks to a major tree planting programmes.

    I think it'll realistically be a 70 year cycle for trees, 40 years to start absorbing carbon following plantation.

    It makes me wonder about how we might need to consider material density, such that CLT, for instance, is avoided other than where necessary and stick frame/SIPS/Panels (depending on infill material) are prioritised due to less timber density.

    Posted By: WillInAberdeen

    The building industry is still driven by SAP 2012 which uses 519g/kWh for electricity, now massively too high, which discourages electric heating and over-rewards bolt-on PV, and doesn't consider the embodied carbon at all.


    This is a perennial problem. Proper research has the unfortunate time lag compared to current levels of innovation and implementation. There's a 2012 study comparing environmental impact of heat pumps and gas boilers from 2012 stating that due to the carbon footprint of the grid, heat pumps were not a sustainable. However it does make some interesting comments about wider negative environmental impact of heat pumps, but again technology is steaming ahead (https://www.escholar.manchester.ac.uk/api/datastream?publicationPid=uk-ac-man-scw:178995&datastreamId=POST-PEER-REVIEW-PUBLISHERS.PDF)

    Here's a link to the abstract of another more recent study reaching a somewhat different conclusion re GHG, but interestingly highlights other serious environmental impacts of heat pumps (Environmental life cycle assessment of heating systems in the UK: Comparative assessment of hybrid heat pumps vs. condensing gas boilers - https://www.sciencedirect.com/science/article/abs/pii/S0378778821001493)
    • CommentAuthorrevor
    • CommentTimeJul 9th 2021
     
    This on news today.

    https://www.bbc.co.uk/news/av/uk-57756991

    RIBA confession they got it wrong in the past
    • CommentAuthorphiledge
    • CommentTimeJul 9th 2021 edited
     
    Posted By: revor

    RIBA confession they got it wrong in the past


    We almost certainly all got it wrong in the past!

    I had a V8 petrol car at one time but I dont blame the car industry for that.
    • CommentAuthorrevor
    • CommentTimeJul 9th 2021
     
    That is their comment, up to them if they want to beat themselves up about it. Generally most do their best in the environment they find themselves in. People don't go to work to deliberately do a bad job, well most don't
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