gravelld

Blowerproof.

I think you're mixing two things: air tightness and wind tightness. You should have both, and the former should be on the inside of the insulation. I would be wary about mastic, instead favouring taped wind tightness membranes.

Thanks for confirming.

Sorry for the slow reply, only just seen this. That's what we're doing. Yep, this is exactly my experience too. Most builders just don't want the chopping back work, and also want to avoid the complexity of working ahead of the installers. In the end I negotiated with the installer that they will chop back and my contractor make good. They are also due in a week or two to check the nature of the current installation. I did get some ok quotes in the end from contractors for the chop back, but I thought the slight premium to have the installers do it worth it in terms of reduced complexity.

I thought the maximum slider from Rationel was 3.5m? Maybe a three door slider?

Yes, the problem is with the weight on the hinges over time causing air leaks. Lacuna make the only Ph certified bi-folds I know of - https://www.phstore.co.uk/lacuna-passivhaus-suitable-triple-glazed-bi-fold-doors . How good they are long term I don't know.

https://passivehouseplus.ie/magazine/new-build/longford-self-build-goes-certified-passive-on-a-budget https://paultestaarchitecture.co.uk/news/RoCo_DoGoods_presentation.pdf Avoid the bling (including green bling), DIY as much as you can. Save money on fittings (they can come later), spend money on the fabric.

Thanks for clarifying.

Thanks very much, very useful. I didn't think to ask about CC as I just assumed they wouldn't take one, with the surcharges and all, or even have the means to take a card payment. But I'll give it a go. So to make sure I understand this... - Pay £100 of the deposit by CC - Pay the rest by bank transfer Then for each instalment do the same split, so long as each instalment is under 30k? It's explained here: https://www.which.co.uk/consumer-rights/regulation/section-75-of-the-consumer-credit-act - I guess the only thing I'm a bit worried about in the process is the fact that "The goods or service you bought must have cost over £100 and not more than £30,000." (it's more than that) and how "potentially by splitting it into 2 transactions" works. I'll speak to them.

As part of our refurbishment project we're going to have some big purchases, for example new windows and their installation. This cost will be in the mid five figures. It is paid through the installer, who then orders the windows from the manufacturer. The deposit is paid according to the full cost including installation and they advised I don't get a receipt from the manufacturers, only the installers. This makes me nervous - what happens if the installers go bust? I wouldn't have any kind of proof with the manufacturers that I have paid a downpayment. The manufacturers are unlikely to go bust, they are one of the "usual suspect" 3G alu-clad manufacturers. So it turned me to thinking about insurance - what sort of insurance do I need? The installer also mentioned something about using a solicitor, but that sounds like a lot of work...

Of course, but whether ignorance or malevolence both should be punished surely?

What you (we) are describing is a negative externality tax (or regulation). There's plenty of them that have succeeded. Granted, plenty that haven't also. Coupled with legislation that prevented land banking, why do you think it wouldn't work? I sometimes think we have got ourselves in this situation where the state is afraid to flex its muscles where it might be appropriate. At this point I don't really understand in what way the volume house builders are economically productive, do you not see some sort of market failure going on right now?

Maybe you should register with Melton as well then.

I'm not sure how it would play out, but you would've thought end price to the consumer would not change; the market dictates that. There are very few things in this world that are priced according to the cost of production. The latter provides a base cost against which a profit margin can be judged as to whether it is worth providing the product/service, but beyond that pricing is determined by a number of factors and costs are a small part of that. And in fact in some cases things are sold at a loss, in prediction of future profits (e.g. drugs given away by a dealer which will hook the user). So the question is, I think, would this lower overall building if the volume house builders withdrew from less lucrative propositions? If it did, I guess that would in turn increase costs as supply is lower. It's difficult this stuff, but I'm trying to point out the relationship is unlikely to be direct.

Depends what you mean by "really" hard. If you're using money as a proxy, then insulation. If you're meaning bother, time and disruption, then air tightness. All uses of plumbing for both air or water, e.g. ventilation, heating pipes.

I'm not self building, I'm doing a limited external refurb in a village north of Melton.

I'm also in Leicestershire on the north-east side. Whereabouts are you? Good luck!

Maybe he just did it wrong. Sometimes a fix is the right one but it has to be backed up with other policy. The JJ appear to be generally upset at life chances and the past thirty years of those they regard as "elites" getting it all their own way. I think their rhetoric is a bit extreme but it holds a grain of truth. It might be time for the upper and upper middle classes to begin paying up. I think this is a false dichotomy. The entire history of human development suggests we can find a way, and all through history there have been people saying "it's the end" - Malthus etc. They were wrong then and they are wrong now, because a fixed pie mindset exists when economic value is considered. TBH installing insulation is probably not to the benefit of global corporations. It reduces wasteage and is purchased once. It's an example of building wealth rather than perpetuating wasteful rentier expenditure. The "they're telling you to turn your thermostat down" is exactly the kind of finger pointing the deniers continually get away with. But it's very limited; it plays on our inability to think outside of our context. I think we should think bigger. We should think about how to engineer our way out of this. Fix the problems, so we don't even have to put up with switching off the heating. Put in place long term solutions. Build wealth such as a high performance building stock. We've put a man on the moon before, I think we can insulate houses. Last time I looked, retrofitting the entire housing stock to a high level is very expensive, but probably not a lot more than HS2. I know what I would prefer, and which would drive better economic outcomes.

This is my fault - I used the C word (centralisation) but I didn't necessarily mean bureaucracy. I meant that Government use its levers to enact change, rather than expecting "nudges" to individual behaviour or some other silver bullet (go technology!) to come along out of nowhere. If you take the example of house building - we will go on building crap houses while there's no incentive to not do so; volume builders are run by their quarterly report. One fix is to mandate higher standards, for example a sensible air permeability target. But regulation is one example of a lever Government could pull. The biggest lever of all is a carbon tax. A carbon tax would probably solve the problem without the need for any downstream bureaucracy, but it would probably need to be internationally agreed... so good luck on that.

Why do you need both units? Isn't the permeability enough for the extractions fans to suck through?

In the late 1930s, the Government did not say "Ok everyone, Germany are getting a bit fighty so we're going to need everyone to buy some guns, tanks and planes". The effort was centrally managed. If this is to be fixed, individuals will not have to face personal financial investment decisions. (One of) the key differences to 1939 is that the threat of invasion is far more apparent, immediate and obviously existential. Climate change is none of these things. It will be a slow decline, those with more power will be less affected and we may find ways to balance the effects which become ingrained into our daily lives so we don't even notice them. They cause economic loss because they are non-constructive, but we don't notice them. There will always be people rich enough to insulate themselves (literally) from the effects. Somehow we're going to have to shift our mindset to the long term, something the Anglo-West is particularly poor at. We're going to have to tackle this in a more centralised route, through taxation, through regulation, through incentives and more. What's curious is the way the media select the mouthpieces for either side of the debate. They seem to select the craziest voices from both sides; the fingers-in-your-ears types like Nigel Lawson (who was last correct about something sometime in the mid 70s) and the de-growthers who provide such an easy target for the sceptics to point at and say "look, he's trying to stop you eating steak!". Oh, for the days of late 90's centralism.

We're changing our windows and I'd rather go with no trickle vents and have an actual ventilation "system" rather than relying on air pressure to ventilate the house. Before I go into the details, some constraints: - This is a refurb and people are living in the house - I can't afford HRV - I don't want the disruption of ducting - I don't like the concept of PIV - pushing out moisture laden air through holes in the fabric does not sound like a good idea Our current air permeability (before new windows) is 5.8 m3/hr/m2 @ 50Pa. Our floor area is 285m2, five bedrooms. We have seven wet rooms (1 x kitchen, 1 x utility room, 2 x toilet, 3 x bathrooms). My reading of the guidelines in the AD is that we need to provide a minimum l/s of 85 l/s on a m2 basis. If the units provide 12l/s that almost covers it. Is the calculation that simple? I've been looking at units like these: https://www.vent-axia.com/range/lo-carbon-solo-plus-selv (the HT version to ensure ventilation goes up when humidity does) I also believe Nuaire have similar units. Are these units suitable for continual extraction and will seven of them (for each wet room) be "good enough" to meet the demands of BC?

Ok, I'm just going to put this out there: https://www.secotherm.co.uk/secoflex-exterior-wall-coatings-brief/ Now, there a lot of things on this that trigger my spidey sense: - "Overly salesy" copy - Competing firms have some bad reputations - No real link to the underlying product used However, their quote for a full render repair and recoat with all enabling work is competitive (and would reduce project complexity) and the product (which I have sampled) does indeed appear to be very elastic. They offer a 10 year guarantee against any kind of cracking, although I'm guessing it's one of those guarantees that might be a bit difficult to actually enforce. There is discussion of a sister product, "SecoTHERM" on the MSE forums but that is more around the dubious claims it makes for insulation performance (I agree with the cynicism). But I'm not interested in the insulation performance, just the ability to withstand smallish cracks in our S&C render. Has anyone experience with coatings like this?

That looked like a wind tightness or weather proof membrane, not an AT one.

When they were fitting the insulation in the plywood boxes it looked a bit prone to user error. My wife spotted some gaps. Any reason you couldn't fully box them in and pump them with cellulose/EPS? Given plywood itself is very airtight, I guess the air tightness layer comes from a mechanical fixing between the boxes? I didn't see any AT membrane.