Big Jimbo

Thats a building regs fail. Minimum 30mm into the insulation layer. Yes, big thermal bridge. It should also adversely affect your saps result. What sort of cill has been fitted, and how far outside the blockwork does it overhang ?

If you are having the walls plaster skimmed, then the plasterers will take up the 3mm, so not a huge problem. If you are going tape and fill, you will need to take the boxes out, and recess them further into the wall.

There is no need to each have your own surveyors. You can both agree to use the same surveyor who can draw up the PWA. If you go down the route of each having One, you have to pay for both of them. When they don't agree with each other, you will have to pay for a third to make a ruling. It will drag on forever, and cost you a fair amount of money. Try and get your neighbour to agree to use a single surveyor.

@ADLIan No i understand that it will be costly. It's just a shame, as previously there were various drawings available, that if you followed you would get some credit for. seems a great shame that they did away with them, and now there is basically nothing that has replaced it. I wouldn't expect manufacturers to have to produce the drawings that show there products in 20 different uses combined with other peoples products. I don't think it is unreasonable for someone like BRE to have a set of standardised drawings that can be followed. I have got 5 drawings for details of thermal bridging. I shall follow them anyway, but seems a shame that because they are not accredited junction details that will make a big difference to my thermal losses, they effectively are worthless. I am going to speak to BRE today to find out how much it will cost for me to have them looked at and accredited. I shall report back.

I think i will simply do what i need, to get the required pass. spend my money on sexing up the visuals. As i have 3phase, i might have a look at putting a quick electric charging point in (car charger is a condition) That might get an oooooooooh. 😂

@Dave Jones i will ring BRE in the morning. from my reading today, i'm not sure there details are still in use. The problem with some of the manufacturers published psi values are not full solutions for whole elements, but rather specific products. I will also speak to my saps bloke . One of my issues for instance is that due to my cladding on the top half, i can't get my windows 30mm into the insulation, due to the depth of cills available. Therefore, even though i have a method to counter this, unless i have my solution thermally modelled by somebody who will be accepted by saps assessors (prob BRE) Then i will get no sap calc benefit, and will have to put up with the default element. In view of @nod experience, i think i might just save my money, and spend it on a boiler water tap. I have spent most of today reading on a lot of forums about saps, some of them with contributions for sap assessors. The general thoughts are that even the new sap 10.2 are not fit for purpose.

I've seen work done on here for free by @etc , worth more than a grand. Frankly, the comments on here make you wonder why he bothers. If i had known about him before, and having seen what he has produced, on here, for people, for free, i would have gladly paid him a few bob, or given a donation to a charity of his choice. I have absolutely no doubt that he would have made my initial design that i got through planning, so much better. In the end, my structural engineer is also an architectural technician, and he did exactly that to the internal layout of both floors. Seriously, is it not 6 years to qualify as an architect ? There are always going to be shite professionals in all industries.

The Labc construction details are not to be used after 2021.It say that on the link @Dave Jones

Looks fantastic. Well done @Dave Jones

Thanks @ADLIan i will take a look later.

I'm no expert, but i have been around the building industry for 30 years. Interested in the process of building since i was about 10. I'd like to think i know, although not claiming to be an expert, about attention to detail, thermal bridging etc. The point i was trying to get across was that if you are not going to get any credit for "doing better" than why bother. I'm not talking about the self builder on this forum. Move the small or large developer, chucking up houses to sell to the poor general public. I believe @nod is currently marketing for sale One of his previous self builds. From memory the only thing people were interested in were the kitchen tap, and hob. Sad, after the effort he made to do "better". If the big boys are not going to get any credit for spending extra money on improving thermal junctions, they will opt for the cheapest things to get the best saps score, which might not be the fabric first approach

Find out if your planning officer is married. If he is, a hooker, some coke, and a photo. He will let you have whatever you want. Works every time.

So you want to build a new house. You would like to do slightly better than Wimpey Homes. Before the new 2022 part L came into force, you could get details of how to improve your many thermal bridges from sources such as BRE, Labc. Energy saving trust, planning portal. They had best practice, drawings and calculations that were accredited, and gave improved psi values that a saps assessor could use to bring up your saps score rather than using the default values for all your leaky areas, such as around your windows, floor to wall junction etc. Since the introduction of the new 2022 part L, these have been withdrawn. So if you now want to make improvements there are no accredited details to follow and you are expected to get thermal modelling done on these area. Even if you do that, they wont be accredited, so cant be used in your saps calcs. Today i spoke to 3 different saps assessors who all told me that until some new accredited details are approved and done that everybody is just going with cramming a load of solar on the roof. What happened to fabric first ? So like most on here, trying to do a bit better. Looking carefully at all your rubbish thermal junctions. It would appear to be a waste of time in relation to your saps score. Therefore, should i just build to crappy standards, and stick some extra solar on like the big boys seem to have started doing. I will get a better looking saps ticket. Are we starting to go backwards ?

Can i ask. Over what distance ?

Blinking heck, i'm still confused. (Not hard) So is it, big loss, or little loss ? When looking at everything, which you are when building a house, there is always a question of cost verses benefit. I was reading something last night about full fill cavity. It said that the blockwork outside should not be bucket handle pointed, but packed, and scraped off flush. according to the article, the bucket handle finish losses were considerable. I know we should all be looking at fabric first, but you can get tied in knots if you are that way inclined.

So the 3.4w is what. Loss per meter ? And what about block in wet , or dry zone ? would that make a difference ?

Sorry, slab on ground, the DPC would be above the marmox, and in the wet

In my head there also has to be a big difference when using either a floor slab on ground, or a block and beam floor. On a block and beam floor, the "marmox" block would be in a dry zone, ie: DPC under block and beam. However, slab on ground the DPC would be below DPC. So if you are going to use either lightweight block, or marmox, in One situation, the block is going to be in the wet, in the other it's not. Perhaps the super block has less need, or use, if doing block and beam ?

So which is it ? 3.4w for 50 meter perimeter, or 2kw ? These can't both be right unless the 2kw represents a house with a perimeter of a mile ?

That looks great. I tried it with 3 railway sleepers stapped together, dragged along by my mini digger. Didn't do anything like as good a job as yours. I wish i had tried an old 5 bar gate with some weights now.

I love the wall behind the stairs. Your own handy work ?

Now you are going to have to cover them up, to stop them getting damaged. Nobody is going to see them again for several years. 🤣

@Pocster You sexy futhermucker.

I have just used a structural engineer for my drawings and structural calculations. I will have to add some information to them to make them complete for Building regs submission, but not a great deal. The last time i used an architect, i got something that could not actually be built. IMO, an architect is good for initial ideas, but at the point you are happy with basic layout, i would hand it over to a structural engineer.

@Iceverge Thanks for doing that, and making it so easy to understand. It's funny how so many people state that if you don't do it a certain way, your bills are going to be through the roof, and the planet will explode. So with using number 4, and actually getting my wife to turn the odd light off, i would be doing just as well as all the Greens ? Obviously, they would still be doing better than me, because they would never leave a light on. Thanks again, great to see it actually worked out.