Gibdog

Thanks chaps, I'd read that heat loss paper a while back but good to be reminded @Nick Laslett If we were to have to insulate (for thermal reasons) the stacks - would it therefore just be the one that goes outside, rather than the ones with AAV's?

Thanks guys, that’s great to hear - was going to be a real headache trying to get it for Monday/Tuesday. Once the slab is in, he’s said we need an airtight collar to seal the SVP to the concrete and then the rest of the stack can be constructed and insulated. Does that sound right too?! Any tips on products/materials for that part?

Thanks @Russell griffiths yes, his concern is thermal bridging - he admitted it’s small but as there are a lot of them they add up (we have 7 x 110mm pipes).

Hello, We’re doing an MBC passivehouse (slab too). Our PH consultant has said we need to wrap the SVP’s within the slab in 25mm armaflex tuff coat - up to the slab seal. I.e. within the concrete. MBC and Groundworks team say they’ve never done this before. Have any of you guys?!

That would have been good! But already doing a passive raft foundation...

Ah thanks for jumping in on this everyone. We did more checks and the topo was wrong - they had marked a fixed point in the pavement incorrectly. I'm trying to get them to at least refund the cost of the survey given the extra costs we've now incurred to backfill it to the correct level. Pretty annoyed as I kept telling the GW team that it wasn't right and the guys on site agreed but the head guy assured me his engineer had tripled checked it all and our architects must have designed it to be lower. My first big lesson! Having to tell myself that BC might have asked us to dig that deep anyway to find the right ground.

Hi there Buildhubbers, Hoping someone might be able to offer some advice. We've excavated (for a raft slab) and are now backfilling but the engineer/groundworks team have marked FFL below the level of the surrounding area (triple checked with laser against fixed points on road and pavement). I attach a couple of pics looking east and west showing the FFL (blue line). Both neighbours' FFL would be higher and, to make ours 150mm above ground level, it will require reducing the surrounding ground which just doesn't sound right to me. I've attached our topo survey and a screenshot of the architect's section detail - FFL is set to 100.15. Can anyone help/comment...?! I feel like there must be a simple answer but I'm flummoxed!

Thank you so much @Nickfromwales - those little tidbits are so useful! Do you have any idea about Virgin connections? I've spoken to countless people there but no-one seems to have a clue what to say to me!

Thank you - that's a lot bigger than my list! I'll check again. May I ask what the solar conduit is? Are your panels not on the roof..? And your broadband - is that with Virgin by any chance? Are you using the same duct as electrical cable..? Many thanks.

Hi @Bancroft, I posted a similar (but much less through) Q just before Christmas and someone pointed me to this thread. Have you finalised the penetrations? Would you be up for sharing it? I'm at a similar stage and my list feels very small (9!). Many thanks, Gracie

Thank you all so much for your replies - I went offline over Christmas so apologies for not replying. I think this is how people tend to reply...!: Gotcha - didn't know that was a rule! Attached here (format OK?!) Ideally it would be on the garden (north) side - but the mains comes in at the front (south side) - would you then pipe it externally?! Ooo this is great thank you - 1) This is what I was hoping to do but did you not have an issue with BC here? I've read that you can't run services out there?! 2) Thank you. Really silly question - but hopefully this is a safe place(!) - when you say "duct" - are there different types you're meant to spec?! 3)Thanks - not sure I like the sound of drilling through! As above, perhaps I tee it off before it enters the house then pipe it external round the side... I don't suppose you'd be up for sharing your under slab plans would you? I'm a very visual person so seeing how it's done on other projects (especially an MBC one) would be really useful! Thank you too! Great idea to have something running to shed, even if we don't use it straight away. As above - I wonder if you'd be up for sharing the doc you sent to MBC with under slab details?

Hello BuildHubbers, First post for me after months of learning all I can from others on here We're an MBC passive house build in Stratford on Avon. We need to send the service layout for under the slab connections- can anyone help/comment on the below? Or can anyone share their layouts to give me some ideas?! 1. Do all external lights/blinds/Security systems have to be wired directly from inside to out i.e. go through the airtight layer etc, or can you run a duct back under the slab to allow for all external electrics (between TF and timber/brick cladding)? 2. Has anyone had virgin media fitted? Can this come in under the slab too? At what point do Virgin themselves get involved? 3. Water: the mains water will come in under the slab. If we want an external tap, do we need to allow for another under slab pipe back to the exterior? If there's a comprehensive thread on this subject, feel free to send me that way - feel like I've looked but can't find full answers. Many thanks.