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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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    •  
      CommentAuthorfostertom
    • CommentTimeJun 20th 2022
     
    Despair - Mail-worthy
    https://www.theguardian.com/money/2022/jun/20/net-zero-rules-set-to-send-cost-of-new-homes-and-extensions-soaring

    "double-glazed windows will require trickle vents to let heat escape"

    They could have led with the end-bit that's nearer the truth:

    “As the marketplace adapts to the new requirements, and the technologies that support them, the scaling up of these technologies will eventually bring costs down, but in the short term, we will all have to pay the price of the necessary transition”

    "However, the long-term effects of the changes will be more comfortable and energy-efficient homes ... Homeowners will probably recoup that cost over time in energy bill savings.”

    "In the future, there will be increased competition between companies to supply insulation technology ... which should result in lower prices."
    • CommentAuthortony
    • CommentTimeJun 20th 2022
     
    Why even talk about double glazing? 3g for me and all us in the future, now standard in central and Northern Europe.

    I would like to see us talking about energy use reduction rather than energy efficiency.

    Fabric first approach is best way forward so building to high standard is the way to go, reducing energy demand and costs going forward.


    i like level playing field so regulation is crucial
    • CommentAuthorJonti
    • CommentTimeJun 21st 2022
     
    Same here Tony with the glazing. Why even talk about double glazing.

    On regulation it is enforcement of said regulation that is key not the regulation itself. The reason the UK's recently built housing stock is of such poor quality is because there is practically no enforcement. Were it properly enforced then the quality of build would be higher.
    •  
      CommentAuthordjh
    • CommentTimeJun 21st 2022
     
    Posted By: JontiSame here Tony with the glazing. Why even talk about double glazing.
    I was very surprised to get a questionnaire from Which recently about double glazing, with no mention at all about triple glazing (except in my replies!) I think it illustrates how widespread and deep the problem is.

    On regulation it is enforcement of said regulation that is key not the regulation itself. The reason the UK's recently built housing stock is of such poor quality is because there is practically no enforcement. Were it properly enforced then the quality of build would be higher.
    +1

    I'm quite happy with the quality of build on our house; not because of any building regs enforcement, but because I was there all the time, doing their job for them :) And hopefully by motivating people to take pride in their work rather than criticising failures too much.
    • CommentAuthorrevor
    • CommentTimeJun 21st 2022
     
    I do not think I would have had a better result on our house (where I and my wife did most of the work), if we had TG instead of DG. We did consider it but certainly at the time it was not cost effectively with reports by glazing experts that payback would be 90 years over DG. TG is 50% heavier than DG so that was also a factor for us doing DIY and whilst access is easier during build come to replacing an unit that failed, upstairs up a winding staircase it is a different matter. It is claimed a HP will save you money but if your energy consumption has been designed to be low due to good fabric first approach you do n0t need such sophisticated equipment with ongoing expensive maintenance and questionable performance depending on who installed it. Last year our gas bill was £200 previous year £300 so say ave £250 and that is with bottled LPG. It would not have made economic sense to fit TG nor HP and in case you might think it is a small house it measures 325 sqM . It performs better than expected because our solar gain is much better than we thought it would be, and the thermal mass has probably contributed more than expected, the house is built around and incorporating a 1750's farmhouse. This year is the 1st full year of our solar PV and our export payment looks to be more than enough to cover our gas bill. We are also fortunate we do not have cold winters. Horses for courses as they say.
  1.  
    The new building regs/stds in England and Scotland don't say anything about DG as far as I can see, that seems to have been randomly chucked into the article by the journalist (edit: was actually in a quote).

    They specify U=1.2 W/m²K I think (glazing? overall window?) as a notional target, and you can choose whether to go better or worse, then you adjust the rest of the building design to compensate.


    The bigger problem for me is that the manufacture of an extra pane of glass with current technology emits quite a chunk of CO2, and I don't think that would ever be recouped in emission savings, as electric heat/pumps are decarbonising fast. IE 3G isn't necessarily better for the environment than 2G any more, these regs are 10 years too late. YMMV obviously depending on your heat source (solar gain? direct electric? fossil?).

    Unfortunately we will probably have to wait another decade for building regs that address the trade off of embodied vs operational carbon.
    • CommentAuthorJonti
    • CommentTime7 days ago edited
     
    The only thing I would disagree with is that if the manufacturing of the 3rd pane of glass causes so much CO2 it is not worth it why have the 2nd pane as this must be, proportional wise the same. Indeed you could even argue against having the first. I do understand the idea of diminishing returns but I suspect the reason this might be a reason here in the UK is our standards of building are back in the dark ages. If the substance of the building is so poor at retaining heat it is irrelevant how good your glazing performs where as if the building is super efficient then even a marginal gain is worth it.
    • CommentAuthorRobL
    • CommentTime7 days ago
     
    I think that glass question can be answered with numbers, comparing 1G, 2G, 3G upfront energy use and in-use energy saving, and the carbon equivalent. I've rounded stuff here and there, trying to be good to ~10%:

    We have 2000HDD where I live, and carbon intensity is now approximately 0.2Kg/KWh of electricity.

    1G U=6W/m2/K. Losses are 6*2000*24 = 288KWh heat per year per m^2=>58Kg carbon/year/m^2=>1160Kg/20year
    2G U=1W/m2/K. Losses are 1*2000*24 = 48KWh heat per year per m^2 => 10Kg carbon/year/m^2 => 200Kg/20year
    3G U=0.5W/m2/K. Losses are 0.5*2000*24=24KWh heat per year per m^2=>5Kg carbon/year/m^=>100Kg/20year

    Glass embodied carbon is ~8Kg CO2 / kG glass, and 1m^2 of 4mm thick glass weighs 10kG. So the upfront emissions of the glass are:
    1G 8*10 = 80Kg carbon / m^2
    2G 2*8*10 = 160Kg carbon / m^2
    3G 3*8*10 = 240Kg carbon / m^2

    Now we can see that over 20 years, choosing to install 2G instead of 1G when there is no existing window saves:
    (1160+80)-(200+160) = 880Kg carbon (as CO2) per m^2 over 20 years

    And that 3G instead of 2G saves:
    (200+160)-(100+240) = 20Kg carbon (as CO2) per m^2 over 20 years

    Wow, I'm glad I went through that - I think Will is right. While 2G easily beats 1G, 3G is roughly carbon neutral with 2G over a 20year period. As the elec grid decarbonises, it will drop the carbon cost of glass and also of (direct elec) heating. Maybe 20 years is pessimistic so 3G is better... however heatpumps should be the killer for 3G as they will drop all of the in-use carbon emission figures- but not the high temp glass manufacture carbon cost, making 3G worse than 2G overall, over 20 years.
    • CommentAuthorJonti
    • CommentTime7 days ago
     
    But wouldn't that HP point also be applicable to 2G too!!!

    On the rest of your post RobL I agree but it assumes that carbon emissions are the only parameter which I would suggest is not the case. 3G has the advantage of being thermally more efficient from an insulation point of view. If the glass is produced in a low/no carbon emission way then the emissions point disappears.
    •  
      CommentAuthorfostertom
    • CommentTime7 days ago
     
    V interesting - I love scientists' (I was one, sorta, once - A level Phys/Chem/Maths) way of back-of-envelope reality-checking. Cuts crap.

    Jonti, I'd say that RobL's CO2 focus is good proxy for "thermally more efficient from an insulation point of view".

    However, Passive House for example values 3G for more than raw heat loss - even more so, they say, it's about that final increment eliminating the sensation of cold radiation, usually interpreted as draught, the result of which is users' complaint-free contentment to let the system/package do its thing rather than fiddling with controls etc - perhaps the single factor that makes PH's predicted vs in-use results so relatively reliable.

    Carbon content of glass manufacture - I don't know, but surely if steel's well on the way to switching to renewable electric 'fuel', glass should be an easier prospect. Anyway, glass is one of the best materials, from the %age recycled POV, incl considerably lower carbon in re-manufacture of same - or perhaps window glass has to be virgin?
    • CommentAuthortony
    • CommentTime7 days ago
     
    I like 3g as it cuts out noise, is much more comfortable to live with, better ironmongery, better quality. It helps me not to need a heating system or pay heating bills. One off cost, long term savings
    • CommentAuthorSimonD
    • CommentTime7 days ago
     
    Posted By: fostertomthey say, it's about that final increment eliminating the sensation of cold radiation, usually interpreted as draught, the result of which is users' complaint-free contentment to let the system/package do its thing rather than fiddling with controls etc - perhaps the single factor that makes PH's predicted vs in-use results so relatively reliable.


    I do wonder when someone is going to conduct a proper behavioural economics and environmental study on this. Being that I work professionally in the field of psychology I am interested in how we respond to the sensation of cold draughts. It's is known that when we do, we typically overcompensate in turning up the thermostat much higher than really necessary and thus the energy consumption curve is 'doubly' non-linear (once non-linear due to increase in target room temp and secondarily due to overcompensation). I even have some old texts dating back as far as mid 1800s talking of this very topic but with regard to open fires and ventilation!

    Because of this I believe that the overall benefit of 3g is much greater over its lifetime than pure energy loss calculations. Assuming the build is actually built airtight and the windows are installed as such - not a guarantee as such...

    Posted By: tonyI like 3g as it cuts out noise, is much more comfortable to live with, better ironmongery, better quality. It helps me not to need a heating system or pay heating bills. One off cost, long term savings


    I'm currentry also appreciating a noticable reduction in summer heat gain from my 3g windows.
  2.  
    Tom, unfortunately "renewable steel" and "renewable glass" and "fusion power" are all at the same stage - demonstrated at small scale, but unlikely to take over their respective markets during the lifetime of these building regs, or indeed within the next few decades.


    Installing (say) a 3G window or a concrete slab in the 2020s/30s will irretrievably commit their manufacturing emissions into the atmosphere, so it is irrelevant if glass manufacturing goes on to decarbonise in the 2040s.

    The 6th Carbon Budget is based on further decarbonising of UK electricity (hence electric heaters and heatpumps) between 2025 and 2030, as a large number of offshore wind farms and solar farms come through development. Any building component needs to "pay back" it's manufacturing carbon before then, or else it will never get a chance to. I agree with Rob that 3G will not payback before then, in my building at least.

    So during this next period, focus needs to switch away from reducing energy usage, towards reducing high-carbon materials. Once low-carbon glass/cement/steel/etc become available in the 2040s, the pendulum might swing back again. It's a challenge for standards like PH or building regs to adapt themselves to this.


    On the psychology, I was surprised that a previous home came with roller blinds as well as lined curtains. The "double curtaining" likely didn't add much to the U value of the DG, but did have a very good effect on the perception of radiant temperature
    •  
      CommentAuthordjh
    • CommentTime6 days ago
     
    Posted By: WillInAberdeenThe 6th Carbon Budget is based on further decarbonising of UK electricity (hence electric heaters and heatpumps) between 2025 and 2030, as a large number of offshore wind farms and solar farms come through development. Any building component needs to "pay back" it's manufacturing carbon before then, or else it will never get a chance to. I agree with Rob that 3G will not payback before then, in my building at least.
    So should we be building 180 km of new steel pylons to carry renewable energy? :devil:

    https://www.nationalgrid.com/electricity-transmission/network-and-infrastructure/infrastructure-projects/east-anglia-green-interactive-map
    https://eastangliabylines.co.uk/shock-as-national-grid-proposes-180km-of-new-pylons-across-east-anglia/
  3.  
    To be fair, people who invest in wind turbines in someone else's back yard, shouldn't be surprised if the electricity is delivered to them on pylons across their own back yard! Directly or indirectly, we are all doing just that.

    There have been a huge number of windfarms in northern Scotland over the last 20 years and the associated pylons taking the power down to the South have been almost as controversial. The line through the Cairngorms National Park went ahead, but some subsequent proposals have been stopped and replaced by HVDC underwater lines running along the coast, as the East Anglians are requesting for theirs.

    https://www.pressandjournal.co.uk/fp/news/environment/1157242/energy-giants-super-pylon-scheme-between-highlands-and-north-east-dropped/

    https://www.4coffshore.com/news/ofgem-gives-provisional-approval-for-eastern-green-link-nid25293.html
    •  
      CommentAuthordjh
    • CommentTime6 days ago
     
    Posted By: WillInAberdeenTo be fair, people who invest in wind turbines in someone else's back yard, shouldn't be surprised if the electricity is delivered to them on pylons across their own back yard!
    Yes, not asking about that. Purely about whether we should be making steel.

    Though offshore HVDC seems to make a lot of sense for a lot of reasons, as does an offshore water pipe from Scotland to East Anglia :bigsmile: :devil: Maybe they could do a bulk deal?
    • CommentAuthorphiledge
    • CommentTime6 days ago
     
    Two electrically insulated water pipes one +ve and one -ve. Job done
    •  
      CommentAuthorfostertom
    • CommentTime6 days ago edited
     
    <blockquote><cite>Posted By: WillInAberdeen</cite>"renewable steel" and "renewable glass" and "fusion power" are all at the same stage - demonstrated at small scale, but unlikely to take over their respective markets during the lifetime of these building regs, or indeed within the next few decades</blockquote>

    Renewable steel is very much further ahead
    https://www.theguardian.com/science/2021/aug/19/green-steel-swedish-company-ships-first-batch-made-without-using-coal
    - on the brink of commercial uptake and industrial use, for compounding-complelling reasons, which, like renewable energy itself, can go even faster than the most hopeful projections. At that point, use of steel for pylons, like use of renewable energy itself, ceases to be a carbon issue.

    Puzzling that renewable glass is still only in prototype
    https://ww3.rics.org/uk/en/modus/natural-environment/renewables/the-75-percent-problem--making-greener-glass.html

    But both streets ahead of fusion.
    •  
      CommentAuthordjh
    • CommentTime5 days ago
     
    Posted By: fostertomBut both streets ahead of fusion.
    Hmm, I might bet against you, just for fun :devil:

    Those articles don't seem overly optimistic to me. One prototype steel plant and the proposal of one other (which I'd heard about before) making use of Sweden's almost unique position. Nothing about the cost of the finished product. It's a far cry from that to most of the industrial steel in the world being produced in that way at equal cost to existing steel plants.

    And the glass article described the problems, so I'm not sure why you're puzzled.
    •  
      CommentAuthorfostertom
    • CommentTime5 days ago edited
     
    If it can happen in Australia (solar) ...
    https://libertysteelgroup.com/news/reinventing-steel-for-a-sustainable-future

    They're talking 3-step:
    1. Better capture and re-use of scrap steel worldwide (like, trainloads of Russian scrap, part of the 124s-to-Ladas deal, so degraded Fiat steelworks' metallurgy that for decades all mediterranean steel products rusted like hell, in other climates)
    2. substitution of natural gas for coke
    3. Substitution of green hydrogen for gas.

    And north UK (wind) ...
    https://www.sheffield.ac.uk/mecheng/news/regions-renewable-energy-could-power-steel-industry-revolution

    Remember, this is a debate about the embodied carbon of a third sheet of glass. Looks presently hard to justify in embodied terms, but much so more in terms of user cooperation with (non-sabotage of) energy demand reduction measures. But developments as above confidently suggest that the future trend is to reduce its embodied carbon too - not by 2025 but exponentially thereafter.
  4.  
    "more than half [of the lifetime emissions] of residential buildings are used up in construction", says the editor of Architects Journal.

    Is that figure correct? Anyone know where that number comes from?
    https://www.theguardian.com/business/2022/jun/24/not-just-any-building-why-plans-for-ms-flagship-store-hit-a-raw-nerve


    Separately, an industry proposal for a new "Part Z" to be added to building regs that would require construction emissions to be assessed and limited (initially for larger developments)
    https://part-z.uk/proposal
    • CommentAuthorRobL
    • CommentTime5 days ago
     
    The better you build, the more likely that statement is to be true. Some figures below for us, I'm afraid they could easily be 50% or 200% of any of them though!

    In our case, 1963 brick and concrete 4 bed house, estimated 50tons CO2 build emissions back in 1963. When we first moved in we used 24MWh/yr gas+elec energy =>5Tons/year emissions, so in use emissions took over after 10 years, back in the 70's.

    Since then I think ~ 5+4+2 tons (4kWp PV + EWI + new windows). Googling finds anything from 2T to 10T as the embodied carbon of PV, bah.

    Now we use net elec-PV = 1MWh/yr =>0.2Tons/year. Upfront is easily the most important now! Maybe taking just the 11Tons I've done, gives a crossover of 55 years.
    If we built the house from scratch as it is made now that crossover is after 61/0.2=305 years!
    •  
      CommentAuthordjh
    • CommentTime4 days ago
     
    Green hydrogen isn't going to be used for steel production; it's too expensive. MOE is a better process, and even that will require an additional 20% of total generation capacity. How much steel, concrete, plastic etc will that generation capacity need?

    The only way we'll ever get to zero carbon by 2050 is if we all stop breathing for a couple of weeks.
    •  
      CommentAuthorfostertom
    • CommentTime2 days ago edited
     
    https://libertysteelgroup.com/news/reinventing-steel-for-a-sustainable-future , as linked to above, definitely plans green hydrogen - the article seems to me slightly better than 'promise all, deliver much less' greenwashing. And https://www.sheffield.ac.uk/mecheng/news/regions-renewable-energy-could-power-steel-industry-revolution emphasises that it depends upon getting to excess renewable generation (excess to present demand less reductions).

    I think it wold be foolish to rule that out, along with falling renewable costs. Of course, the cost of all UK grid energy is going to be kept high by the burden of subsidising nukes, but I'd guess that green steel, aluminium, glass etc makers will build their own generation, even if it's carried by the grid.
  5.  
    >>>>>>>"excess renewable generation (excess to present demand less reductions)"

    Electricity demand is going to increase, as transportation and heating are electrified (is roughly going to double in the UK). Steel/glass/aluminium/cement will also be in the queue for that renewable electricity - will be interesting whether they can afford to buy their ways to the front of the queue in 2035, or wait till 2050.

    But the UK manufacturers are fairly irrelevant, the majority of those materials are imported from S Asia. So what counts is the timing at which "excess renewable generation" becomes available down there.

    Also remember that a blast furnace is a big capital investment with an economic lifetime of several decades. The world is not going to demolish its existing fleet early, just to rebuild them as electrolyzers, the best that could be expected is a rolling replacement as blast furnaces reach end of life.


    The price promised to Hinckley C (£89.50/MWh) suddenly seems like a bargain, compared to present market prices for gas/coal/wind electricity (£155/MWh). But as we discussed, those prices don't include large externalities: multiday storage for renewables (£100/MWh?), CCS for gas (£70/MWh?), or decommissioning for nuclear (£unknown).

    The embodied carbon in renewable generators was used as a stick by their opponents in the early days, but was debunked - the carbon payback of a wind turbine (10-20gCO2/kWh) is months rather than years if it replaces a fossil generator. By inspection, that would also apply if it replaces a coal-fired blast furnace or a petrol-powered car engine or a gas-fired glass furnace.

    There are lots of bright ideas emerging for green steel production, you can electrolyse the ore directly at high or low temperatures, or electrolyse a reducing gas like hydrogen or carbon monoxide, or use natural gas or biogas instead of coal and capture the emissions. Most of the energy is for heating/melting (rather than for chemistry) so other fuels are possible and heat could be reused and pumped. Each idea will have pros/cons that need to be demonstrated at pilot scale. In that sense, these ideas are all less developed than fusion power is, maybe they are about where PV was at in the 1980s.

    If we can't wait that long, then better just to use less of those materials in the meantime and build houses out of timber and stone instead. If only there were some building regs about that!
    •  
      CommentAuthorfostertom
    • CommentTime2 days ago edited
     
    Posted By: WillInAberdeenBy inspection
    I love that phrase - are you a Structural Engineer Will?

    Posted By: WillInAberdeenElectricity demand is going to increase, as transportation ... are electrified
    Here'a a straw in the wind - blurb, but still ...

    "The automotive industry’s strategy so far has been to add more batteries in order to deliver more range, leading to increased weight, the need for high power charging stations, and increased CO₂ emissions per vehicle ... With our [solar charge supplement as you drive] technology, any power outlet in the world becomes a charging station. Our radical focus on energy efficiency [several radical measures, not just weight] delivers more range with less battery, reducing weight and CO₂ emissions per vehicle. With the optimised solar roof, this allows a user to drive for weeks or months without charging. Our approach is unique in the EV landscape ... Due to the reduced need for charging stations, Lightyear offers a solution that can be adopted worldwide and can scale faster than current EVs. We can reach large parts of the global market, years before any other car manufacturer."

    But not at the price E250k of their forthcoming first offering
    https://www.theguardian.com/environment/2022/jun/25/keeps-going-driving-first-production-ready-solar-car-lightyear-0
    but E25k projected for their 2025 version.

    Nice factoid:
    "9,460,000,000,000 kilometres
    This is the number of kilometres that all cars combined drive in a single year. It’s a big number. In fact, it’s a light-year, powered by fossil fuels."
    •  
      CommentAuthordjh
    • CommentTime1 day ago
     
    I've been following the Sono Motors product development for a while. They seem to have a more realistic product and set more realistic goals.

    I don't understand this bit in the blurb you linked to: "In optimal conditions, the solar panels can add up to 44 miles a day to the 388-mile range the car gets between charges, according to the company. Tests carried out by Lightyear suggest people with a daily commute of less than 22 miles could drive for two months in the Netherlands without needing to plug in"

    So 61 x 22 = 1342, which suggests they estimate the actual amount of charge per day at (1342-388)/61 < 16 miles if we're very generous and assume the battery is 100% depleted. So why say 44 when they believe reality is 15.6?
    •  
      CommentAuthorfostertom
    • CommentTime1 day ago edited
     
    A commute of 22mi = 44mi round trip? And it's 'optimally ... up to' 44mi; their tests show over a typical 2 months it's (you say) 15.6mi, reliably within the 22 (or 44).

    Lightyear key factors (apart from top PVs twice as big as the Sono's, but unlike the Sono, no door-side PVs):

    Like Sono, four Slovenian motors, one in each wheel hub, hence no driveshafts, transmission or engine bay, thus less car-volume per passenger or junk-in-trunk;
    Tho 4 big-magnet lo-rev motors prob heavier than 1 hi-rev central motor, overall weight reduction, hence lower power, hence lighter;
    Lo-resistance tall skinny tyres;
    Special lo-resistance bearings here and there;
    Exceptional aerodynamics - lo air resistance (unlike brick-shape Sono);
    Because supplemented by solar, batteries for effective range smaller, thus lighter and floor lower hence passengers/roof lower, helps aerodynamics, and again, less car-volume per passenger or junk-in-trunk;
    Advanced materials for lower weight; hence smaller motors, lower weight;
    And so on - virtuous cycle.

    But still 1.5 tonnes - a handful;
    High wheel-plus-motor weight to 'unsprung' body weight ratio - which is a major factor (when spring/damper suspensions react one heavy body mass against the oscillations of several minor wheel masses) against good wheel attitude control/handling/cornering/smooth riding over bumps;
    Skinny stiff tyres ditto;
    So how do they keep it E250k comfortable, and on the road?
    I suspect some v clever AI'd active suspension, which reacts instantly to hydraulically/pneumatically yield each wheel to its bumps almost before they happen, without resort to springs/dampers, whilst keeping all level and off-the-ground via all the accelerometer/tiltometer/3D GPS facilities of the average smartphone.
  6.  
    5m² of nearly-horizontal PV is going to generate about a couple of kWh per day, so save a couple of hundred quid per year, or did I miscalculate? Not enough to travel very far in an EV, or to pay off £250k, but noted their claims about super low friction.

    However a genuine 388mile range would be plenty for most people's weekly (fortnightly?) usage, with a rapid recharge during the supermarket trip at the weekend.
    •  
      CommentAuthorfostertom
    • CommentTime1 day ago edited
     
    Their whole point is, for most users most of the time, to eliminate recharging at supermart or even at home-13a.
    Wp/m2 development of PVs isn't near its limits yet, and thin-film cover-every-surface-incl-transparent PV is on the way.
    This aims to obsolete the present rush to public quick-charge stations. For trucks too, ships, planes???
   
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