Thorfun

amen brother! 🫡

Thats actually a thing……it’s called Passivhaus 😉

we didn't use any mechanical fixings to tie the insulation to the slab. tbh i don't know what will happen if/when the heave protection is gone but our SE (Tanners) never mentioned it to me and so i'm not worried at all. maybe it's different with piles?

and there is also a habit of humans not admitting they're wrong especially when there's been a large financial outlay or it might lose them face. so just because someone says "it's brilliant and works exactly as i hoped" or "i'm really happy with my purchase and wouldn't have done anything else" doesn't necessarily mean they're telling the truth as they don't want to look bad or admit they made a mistake. it takes a brave person to admit they were wrong

i understand this but one thing i've learnt (and there have been many!) during my journey is that not all 'accredited' professionals are created equal. nothing beats getting the opinions of others (even if they are complete strangers on the internet) as they generally do not have any sort of vested interest in the questions you're asking or solutions you're trying to find. and then you can compare the answers and make an informed decision. Also there are many ways to skin a cat. and just because someone says one way is best doesn't mean there isn't another way that is equally as good. just my 2 cents.

passivhaus is below 0.6ACH. i would hazard a guess that as a certified passive house designer your architect is concerns that a property of the size you're proposing just won't get passive house accreditation so hasn't gone down that route as has possibly chosen an ACH that's attainable for such a large property.

sounds a lot to me. but if that is the going price it makes the deal i made with my electrician to allow me to do the 2nd fix all the better when i think how much i've saved!

if i knew then what i know now things would be different! obviously, i didn't know that Putin would invade Ukraine or that material prices would keep rising which caused a massive issue for us. Also i didn't know how long things would actually take. when people say 'things take longer than you think' they're right! i can't comment on your BC plan and it might be best to get confirmation from a building control authority before you proceed with your plan. there's also the VAT to consider if you're doing it piecemeal as you only get one vat reclaim and doing it in stages could give cause for HMRC to reject your claim if you've been living there for many years before the next stage is done etc. all these things need considering. Also, if it takes the 10 years you're thinking then how will things change in 10 years. i hate to be callous but will those elderly relations still be with you in 10 years? i speak from experience as we planned an annexe to be built post build for my mum to live in but she didn't even survive long enough for us to start the build. live tends to get in the way of all your best laid plans. i do wish you all the best of luck. i can only explain the issues we had and our house is only around 420m2!

i'm fully aware of this trap and we fell in to it as well. now we're at the tail end of our build i advise you to reconsider. the stress of trying to find the money down the back of a sofa or having to do the work yourself to save money and watching the completion date move further and further in to the future is really hard. and then the extra costs involved in the mortgage payments as time slips and the money you try and save by doing stuff yourself just ends up getting eaten up in more mortgage payments is a bitter pill to swallow.

+1 to this. and has the added benefit of sound reduction over timber battens.

That’s a first!!

a bit worried if I tell you I'll find out I bought the wrong ones! 🤣 https://www.aliexpress.com/item/1005004133687443.html the ST8-5DA-N version

good point! I am well below that though. the highest current is the blinds and they're being switched from SSRs.

spoke to my electrician and he said you size the RCBO for the nominal/peak current and use a c-type RCBO to handle the inrush current. so just a 10A c-type RCBO for the PSUB. also, 1.5mm cable is rate to 18A (off the top of his head so don't quote him on it!) so should be good for all my internal cabinet requirements.

I have a magic spreadsheet that calculates all that for me. 😉 each RCBO for mains lighting is max 2A. the RCBO for UFH and towel radiators in the bathrooms has max 5A the RCBO for the external blinds has max 7A I'm using 1.5mm tri-rated. I'm sure that's fine for those max currents but will double check with the electrician. things get more complicated when I need to work out the total current for the 24V circuits as they're all coming from the PSUB. those 24V circuits are currently showing as 42A max if all were on full power. the total of the PSUB is 40A so I should be within that as there's no way all those 24V lights will be on all the time and I will be restricting the power on a number of the circuits anyway. looking at the PSUB data sheet I see this: so that to me sounds like a peak current of 7A but I need to work on 15A inrush current. so, a 16A RCBO for that one and, most likely, a 2.5mm cable but, again, will check with the electrician as (I'm sure you're aware!) my electrical knowledge is...............errr..............limited. 😉

thanks @Dan F. i've watched that video and it makes perfect sense. i will pick up some double ferrules and crack on with it!

i forgot such a thing existed! 🤦‍♂️ don't suppose you have a photo of this do you? although, i probably haven't got space for that as i have nearly 50 relays. lovely. thanks.

ok. that makes sense. only issue i can think of is that i'd have to fit 2 x bootlace ferrules into the Loxone relay ports as it loops through the extension. on the plus side it would dramatically reduce the number of cables i need to feed to the terminal blocks from the relays!

it's very possible but it's no problem at all! these things happen on a journey of discovery and mistakes will be made but as long as we learn from them then it's all good. so, let's look at a solution for my current predicament by working backwards. i want the RCBOs to be in the cabinet. i want a single cable from the CU to an isolator/MCB in the Loxone cabinet that feeds RCBOs that feed lighting circuits and the Power supply and Backup for 24V. can i do that with the Wago connectors i already have? if so how? i would rather not have to buy 70 odd new 3-way terminal blocks as that is quite expensive but if that's the only solution then so be it.

right. i get this. but where does the earth from the twin and earth cables go? at the moment i have the terminal blocks that have the earth connecting to the din rail on the outgoing side of the TB. https://www.wago.com/gb/rail-mount-terminal-blocks/multilevel-installation-terminal-block/p/2003-7646 but in your solution that 3rd row just for earthing doesn't exist? i believe you've previously said that you earth somewhere else.

I absolutely love the fact that you think I have a plan! I can promise you that it will be me that has misunderstood the whole concept of lighting and relays....................and electricity. 😆 I will attempt to draw something for you but I'm not going to have time this evening, sorry. I'll try and put something together tomorrow. thanks for offering to help and please stick with me. although after 16 pages on this thread you'd have hoped I would've learnt something by now.

have I simply run way too many blue cables? could I just jumper the neutrals on the lower side of the terminal block and run a single blue cable back to the RCBO? if so that would leave a lot more room in the cabinet as the number of blue cables would be drastically reduced! no, hang on. that can't be right as I have to take 2 cables from the Loxone relay outputs. so both of those have to go to the terminal blocks.

hey. so I could very easily have ****** up here! it is me after all. 🤣 here's a screenshot of my spreadsheet showing some of my din rain connections what isn't yet installed in the cabinet are the isolator and the RCBOs that will feed the terminal blocks. the isolator will be fed from the CU and will then feed the RCBOs. these will go on the bottom rail next to the Loxone power supply and backup. it was my (mis)-understanding that the live and neutral from an RCBO would go to a terminal block, e.g. terminal block number 1 above which will then be 'jumpered' across all the way to terminal block 17. and then on the top side of the terminal blocks 2 - 17 the actual T&E cable from each lighting circuit is terminated with the live at the top corresponding to the live, neutral and earth on the bottom which connects to the din rail. the reason I ran blue cable from the relays is they enter the second level of the terminal block which is where the neutral wire of the T&E will terminate. is that not correct?

the electrician is coming round tomorrow so I wanted to get my Loxone cabinet on the wall so he can run the feed from the CU. it's not fully wired yet but I've done all the mains voltage lighting so I can make a start on configuring Loxone to get some of the lights working, then I can work on the 24V lights after that. one step at a time!

this is also what the wife is thinking.