Oz07

I wouldn't hold your breath. I'm sure it is coming eventually but surely we are talking decades rather than years

My last place was built to those u values with good airtightness (less than 1 I think on the normal test) and mvhr and I wouldn't of thought it was anywhere close to passiv. I remember doing at energy used per sqm thread on here years ago at the time.

I'm not sure about that. The u values above are surely not going to be anywhere close to passiv? I get what you are saying though the regs have come on a lot in the last 20 yrs. I think they are at about the right level now for mass market homes. Keeping in mind end users. There is nothing against individual builders going the extra mile if they want to, or if they think it will help increase value (doubtful)

Yes always gonna be more expensive for one offs. Then again I suppose there is the flip side where clever folk like yourself can work out all these interactions themselves. The AI was saying we do not have enough highly skilled trades to complete enough houses. Sloppy bricklayers with insulation, rough joiners or not enough engineers familiar with heat pumps. I can believe it.

Seems that institution is a trade body. Its basically propaganda that article. Interestingly the changes don't seem too extreme to me. U value targets are similar. Airtightness is ok don't think I've ever been over 3. It does appear to be more aggro so hopefully I can get planning and b regs sorted before March. Wonder how these changes will effect the housebuilding targets.

https://www.bbc.co.uk/news/articles/cg5l3z7p922o Just reading this article they claim building to passiv standard is 5% extra for houses (semi) and 2% (flats). I wonder why they don't include detached. 2 and 5% seem unbelievable to me. Perhaps detached is a lot higher? Don't forget all the boffin work that goes into designing these houses and understanding how all the different elements will interact. They talk of the new future homes standard next March. I will ask AI what the implications will be.

Tbf its always had fibres in for me. Little like fibreglass ones. I dont know if there are certain ones which are worse. Agilia horizontal is what I used to use but gone with another firm since and use their version of it

I might test it next time just for the craic. Are there videos on youtube

I'm just saying in my experience I've never seen it done. I'm not talking on 1 or 2 pours either. Maybe where I am its a more common product. Strange that availability is so variable depending where you are in the country. We do have quarries close. Also I have always had from reputable suppliers and so have other people's jobs I've been on.

I've never tested it tbf. But then again I've never had a problem with it.

I've found timber span tables you can get 63x220mm c24 to do the job on 400 centres. Expensive though. I'd be interested what works out cheaper c24 or engineered timber joists

Thats a good idea are they readily available? Is there span tables anywhere?

Do you have holcim round there? We have a local quite advanced batching plant. Local businessman set it up and they bought him out. They do it too. Even some of the volumetric boys are doing it round here now but I'd be a bit wary of them.

Did they take it back at their cost?

I'd be surprised if glulam is cheaper so I'd lean towards steel. I have a garage 5x5m with 45x 225 timber joists. Was looking at extending the width to 6m and I don't think you can make it work running the joists this way. I can either put a steel over garage door and run timbers 5m way, put rsj in where current 5m wall is, or you can get I beam/jji joists/posi joists to span the 6m. Would that be a solution for you?