saveasteading

So KwH is a Kelvin weeny Henry. Good to know.

They would need rather a strong flow speed to ensure the expelled air is sent clear. It's simple hydraulics so presumably that's been factored in. I once discounted mvhr totally because none of the manufacturers had thought of this. In those says the heat exchangers were inefficient too. That mostly explains my resistance to mvhr... but 15 years or so is a long time for things to improve at the expense of early adopters.

The pir is horrible to squeeze in when 100 or thicker. Very much easier at 50mm.

The wonders of science. I despair that some people are not prepared to do that.

Me too. I don't like grey wood. I've done this loads of times. We used Sika stain on treated timber. That's 2 layers resisting wasps on the outside, and still 1 on the inner faces. The treatment had to be one of the 'not green or dark brown" ones: your BM will get it in if not their standard.. To keep it looking original we used the Sika 'light oak' colour which you can barely see when applying it. But the timber stays that colour, maybe becoming yellower, and is very long lasting. (Dark colours fade in sun over 10 years). Perhaps the next shade towards brownish is better for rural effect. We didn't try other brands. NB paint overlapping boards before fitting, to allow for movement. I've had wasp nests in the attic and hate to think where their harvest is from. They will also chew pir to form a cavity but that ends up as dust.

You'll get more understanding on BH, not necessarily all agreeing, than from the industry who just do what they do, and repeat what their suppliers have told them. The greatest ignorance and resistance I have found is re air to air. The plumbers, which is what they are, don't understand it in my experience, or simply their supplier doesn't do it. Screeders only screed. Neither understands structure or building geometry. It's a big decision and you might (should) redesign your building methods to suit.

That must be Kelvin weeny Hookes.

And if it doesn't quite? It should work well.

So keep looking. It's truet that the pir market is very competitive. But so should be bats. I got a better price fir PIR from the local than from online, incl from "seconds". And it meant I could order for no waste and get more if necessary. The trouble with pir is that your roof will not be standard cc. 600cc +/- 2? Deduct 45mm width +/- 1. Then allow for twists in the timber. Builders end up cutting small and putting squirty foam in. A pragmatic solution for 150mm fill is 50mm pir, with some gaps, then 100mm mineral wool bats, which push in tight.

If the bco isn't asking perhaps letc it run. An example: in our case the fire service asked for a 10m3 water tank. But bco ignored that. So don't overthink. I agreed btw as, although there is no mains, an appliance could drive adjacent ( and we have 3m3 drinking water). I don't know if the bco gave it that much thought. But bco did ask about fire doors and alarms. Best ask them.

A bad thing to do. Explained elsewhere many a time. The driver is not allowed to do that without your signature. So when it cracks it is not their liability. How flat and level do you want it? The standard test is that you don't see any 3mm gaps under as 3m straightedge whatever the position and direction, even pressing down one end. A slight slope might not matter to you. 30mm is a lot of screed.

That's my usp. I get that. My feet are at 36°C so even the recent heatwave has been lower. Cooled floor at what? 16? So it's a feel-good for the feet, if choosing to go barefoot, but it hardly cools the body. And it's the air temperature that we need cooler. Don't we want to be at 18°C max for deep sleep? It's a luxury to have cool feet and go barefooted ( I find that unpleasant on hard surfaces) and that's an individual choice.

Fwiw. In the steading it is ufh on the ground floor but rads upstairs because headroom did not allow ufh. Rads also happen to fit in the 1.5 storey setup. It works well. It can be done. Current project has huge ceiling heights so is ufh both storeys. Why not Rads? would have been enormous. Because there is no carpet intended. Because we can. I rather like the pragmatic suggestion of @joth. Tell the Architect you note their opinion, but to design for rads for the present and you will review after research. I'd add that I was fairly ignorant on ufh until recently. Had done it twice but in easy, large spaces, and if I learnt one thing, it was that the 'specialist' contractors didn't understand it and just did what they did. The same applies to most designers... the info comes from the trade. I'm dubious about cooling. Hot air is up at the ceiling, and i would suggest is not much affected by the floor or rads being cooler. But your feet won't be hot. The pros and cons inter-relate with construction method and layout. You will be the expert soon.

I wrote this many hours ago and forgot to send. I'd say it needs to be at least as big as the sink being emptied. It will force the equivalent water through to the other side and into the outlet very quickly. The inlet should be at mid height and horizontal* so as not to disturb the silt and floating stuff. The commercial traps tend to be much smaller and depend on their being a low flow, not a sink emptying quickly. * that may require bends from the high inlet down and back again. Remember that the outlet controls the level and the trap volume is all below that.

In my opinion it would be wrong for you take the role. They are professionals and experienced so should do it, and they probably prefer that to the alternative.

For general interest. When written risk assessments became a requirement, we put one together that was about 8 pages long, and attached to it a standard A4 form for each specific task. So there might only be one at the start of the job. HSE snap visits (maybe 10% of projects or one per year) asked to see it. They were able to read it in 5 minutes, and follow up with questions and a site tour. One inspector said he wished all manuals were like this, but that sadly it was changing. What they most want to know. Who is in charge? Everyone on site should know. Then asks that person what is happening today, and show me the relevant paperwork. Then a look at the work in progress and site in general. Often they'd give good advice When I retired, our file had expanded somewhat, as required, but was kept relevant and job specific, and was generally one lever arch, half full. On a major national contractor's site I saw they had 3 very full, big files. I happened to be in their cabin, being a subcontractor, when HSE turned up. The manager couldn't find the relevant bit. HSE not impressed. That file was designed to keep the hierarchy safe, not the site personnel. Mine he read and praised, looked at what we were doing and that was that. The bulk of the paperwork that is just waffle was (and is) of no interest. So do it. They don't expect a professional file for a self- build but would from any biggish contactor you are using. They have always been decent people in my experience. The best bit of advice I can give for safety is to think "what could go wrong" and note the measures in place or sort it. Practically it is often by not having too much going on at the same time. If I could find one of my blank forms I'd depersonalise it and publish it here...but I can't. Maybe someone else can. What you really, really don't want is HSE turning up to you after dealing with a nasty accident somewhere else and finding a shambles.

Let's put this in perspective. How many on here have had a formal visit or request to inspect the site or request to see the safety document? Unless you have an accident or complaint it's very unlikely.

You might have to do it with them and get them to sign. As long as it is logical and sensible they should be OK.

That's the trouble. Many are generic rubbish along the lines of safety being our priority. Also you need to see their insurance... the whole document. Eg I once had a roofer who was highly competent but on checking, his insurance excluded work above 3m. He knew it said that, and it was cheap or all he could get. but nobody had ever checked. I've met HSE inspectors several times. They asked for the paperwork but actually wanted to see competence and safe practices. Hey were genuinely interested and helpful... but tough.I'd hate their job... squashed people, missing digits... look and report. Meanwhile being disliked by the workforce. What they hate is to find nobody in control. On the occasions they told us or our contractors off, they were right. The safety people who like paperwork are safety consultants and company safety officers....

No. Just be safe, use experienced workers and reasonable care and attention. It is to keep people safe not make paperwork. A risk assessment is simple. What are we doing?how? What are the risks? How do we reduce or avoid these? Do it thus and brief those involved. Yes people make money from the paperwork from those who will pay. But HSE basically don't want to report on squashed people.

Eg timber, plasterboard and sundry other materials??

1. 1 length of skirting for the return to the left of the front door, 2.screws for skirting 3. mastic for skirting .. 99. What chance they say that's too much info? Other people have done this so I hope they can advise.

Do you know to what extent? it could be a long list. This is really useful info for lots of us. Thanks for it.

did I type that? sorry. btw that will be a litre of water or so over 25m2 of screed so it will dry in 1 or 2 days. It's one of these strange anomalies, that floorers want the screed to be ultra dry but will then happily paint it with a water based liquid, diluted up to 1:4. I think the instructions say 'allow it to dry'.

It's only fair to say that we don't know the relative skills or responsibilities of these consultants, and that the second one was not responsible for the main design, and may have had an equally acceptable proposal if they had been. There was not zero cost in stiffening the building with ply or osb, and a wind post might have been a good option IF incorporated from the outset.