alfaTom

As saveasteading said - you'll have to ask BC. We can't inform you of that as councils will want to see at different stages BC are really friendly and helpful round here so may as well just ask them.

I'm not that mad 😁 when we moved in it was an old 7kW thing. New one is a fancier 10kW thing with a wee touchscreen, this was the finished article. Mrs had a requirement at least one room in the house wasn't a horrid old 70s maroon bathroom... Yes - that sits as part of the inlet control group block - one feed to UVC and one to soft cold manifold. I do need to add in drain cock and NRVs in still that I didn't mention.

Thanks all, some good points and looks like I've simplified compared to previous plans. I think 15mm runs are likely to be fine, even for the furthest distances. All the information on this site is a blessing and a curse as I wouldn't have known about half this stuff if I hadn't been reading up 😁 Thought the electric shower would get people asking. When we first started the work it involved taking the old oil boiler out so we had no hot water. Electric shower went in so we could still shower, and it's not worth the effort of removing now given how often it'll be in use going forward.

I wouldn't like to guess - I'm not an SE. If you do go digging out then it's always best to do it as quick (and safe) as possible to reinstate the floor. I would have thought 500-600mm would be ok for a short term bit of work. Soon as you're at depth in goes the hardcore so you star to build it back up. But then I'd also say that might not be worth the effort going deeper - heat loss via the ground is less than the roof or walls etc so I'd probably rather put the money into those.

Our foundations in the old part of the house were about 650mm from finished floor level. I remember the builder looking at them and saying you couldn't even build a conservatory on them nowadays let alone a house 😁 If you need to find out the depth of your foundations you could dig a borehole near the external wall for that room - you'll find the foundation jutting out if you dig right down against the brickwork. Then just dig down on the edge of the foundation until you find soil under it and that'll give you an idea on depth. We've had to cantilever pile the old section of house to underpin and the new foundations are ringbeams on piles now so the foundations have been beefed up to a degree which gave me some confidence we wouldn't seriously impact the foundations.

I made a previous post where I got way too far into the weeds on satellite manifolds. To try and clear things up and provide a bit more clarity (as well as help anyone else in a similar situation) I thought I'd post a new thread with the current plans for plumbing in our property. Earlier this year I relaid our water supply and put in a 32mm feed. It's probably OTT, but the cost difference between 32mm and 25mm was so close I decided to go for the larger bore. The house has had all old plumbing ripped out; it used to be on a copper branched system and was gravity fed. I'm going to replace this with a manifold system to each wet room, and the DHW will now be via ASHP & UVC rather than oil boiler and VC. The water feed rises in the plant room where the UVC will be sited (with ASHP on the other side of the wall to UVC) to try keep things together otherwise I'd have a few runs crisscrossing the plant room. Water feed to UVC/manifolds: Tee with 15mm feed to outdoor tap with separate stopcock Main 32mm stopcock with reducer to 28mm Tee with 15mm feed to downstairs toilet and sink (This is because they are the other side of the wall to the feed so easy to supply) 28mm continues to control group (3.5/6) Cold water from control group is then split into hard water and softened Hard water heads to manifold Other feed to water softener (yet to confirm brand; don't really care about single/dual cyl or mech/elec function, more about not losing that pressure.) Softened water will then be sent to each bathroom in 15mm Manifold supplies and their estimated distances: Cold (Hard) water manifold Name Pipe diameter Pipe distance Utility Sink 15mm 8m Kitchen Sink 15mm 3m Cold (Softened) water manifold Name Pipe diameter Pipe distance Downstairs shower 15mm 2m Kitchen Dishwasher 15mm 3m Utility Washing Machine 15mm 10m Family Bathroom (Bath/Shower, toilet, sink) 15mm 8m Guest Ensuite (Shower, toilet, sink) 15mm 9m Master Ensuite (Bath/Shower, toilet, sink x2) 15mm 12m Hot (Softened) water manifold Name Pipe diameter Pipe distance Downstairs shower 15mm 2m Kitchen Sink 15mm 3m Utility Sink 15mm 8m Family Bathroom (Bath/Shower) 15mm 8m Family Bathroom (Sink) 10mm 8m Guest Ensuite (Sink) 10mm 9m Master Ensuite (Bath/Shower) 15mm 12m Master Ensuite (Sink x2) 10mm 12m (Note: No Guest Ensuite hot for shower as it is electric) For the above I am mainly concerned on pipe distance for the hot feeds, with the master ensuite being the furthest away at about 12m of pipe. I've split the sinks into a separate 10mm feed to try get hot water there quicker for handwashing etc, but otherwise I think the rest is ok in 15mm. I've ditched any thoughts on HRC and decided to keep it simple. All pipework will be run in Hep2o where possible. I could reduce the manifold size further by grouping the utility sink & washing machine, and the kitchen sink and dishwasher feed into shared 15mm runs but it should be easy enough to run a second bit of pipe if needed. Most joists are new posijoists so easy to run the pipes, just a bit interesting to clip to. Have I made any obvious mistakes? There will be isolation valves in various parts to help with maintenance so haven't listed them (i.e. control groups, softener). Only other thing I can think of currently is if manifolds should be fed from both ends or not to help when more than one run is active. Thanks all!

CE are working from my sizing - heatpunk shows roughly 8kW heat loss for the property. Couldn't get any heatgeeks or other engineers to attend to review and they all quoted £14k+ to fit ASHP & UVC.

Thanks for the update @HughF. I'm currently in the process of arranging delivery of an ASHP & UVC from CoolEnergy via their MCS grant service. All the other installers wanted an extra £6k on top of the BUS, whereas CoolEnergy can supply the units and do the commissioning for the grant effectively "free" as long as I can arrange the install. I'm looking at the CE-IVT10-EVI which is billed as 4.89kW - 10.47kW @A-3/35. There is a newer model, the CE-ET10 but the capacity on this was slightly smaller at 3.89kW - 7.46kW @A-3/35). It's not on their website yet as far as I can tell. I've attached the spec sheet incase it helps anyone else. Once I've got hold of the kit I'll report back on ease of install & findings. CE-ET10 (QR).pdf

Another month and I am back. Water supply has been connected up by Anglian Water and I have a nice shiny 32mm supply pipe. Left the required inspection pits and details accessible for them as per instructions but they were happy to connect up and head off - so glad I dug those pits back out for them! Looks like I have about 3.5bar pressure off the outside tap. If my maths is right the 45metres of MDPE should be capable of supplying up to 92l/m which should be fine for everything I want to do. I've tried to contact a few local plumbers to discuss plans - basically pay for their time to just go through the plumbing strategy and get them to quote for UVC/HP install, unfortunately not many seem interested. As mentioned on this forum before by others, it seems like buildhubbers are still more familiar with PEX manifolds than most plumbers. If anybody knows of someone reliable in the South Lincolnshire area it'd be appreciated! I have been reading up on some other threads on here including a recent one by @Sunil237 (thank you!) I think I can finally answer the question I stated at the start of this thread: Satellite manifolds are indeed a crazy idea for my use case. I'll be running a central manifold in the plant room that has a dedicated feed to each bathroom and tee off from that. I'll be redoing my diagrams soon so there are some iterations of the progress. Cold feeds to each room will be in 22mm, hot feeds will be 15mm. I thought about running hot feeds in 22mm with an HRC setup but I think I might just be trying to solve a problem that doesn't exist - surely it'd be simpler to run a 10mm alongside the 15mm if I wanted a faster hot delivery to a basin 10metres away; that'd be 320ml of water drawoff based on my GCSE maths... Thanks all for your help (and patience) so far!

Sorry - I meant I had opted for that in my designs. It's not in place yet, so my designs are still tbc. It was going to be 22mm from plant room to manifold in bathroom, with 10mm HRC on PIR. Once I get actual pressure/flow rates I'll then know what I actually need (and what is acceptable for the Mrs) and if I was just horribly overcomplicating everything like @JohnMo said to fix an issue that didn't exist.

So since starting this thread back in November I've only just really looked at the plumbing again since our grant has been approved for ASHP/UVC. Reading back on everything I can see there are really only two things I care about: Near-instant hot water when opening taps High-flow of water On my quest for high flow, I opted for 22mm pipe, and then, to compensate for cold slugs and meet the hot water needs, I went for an HRC. It's possible I'm overcomplicating things here and might need to do some tests before I make a decision. Our old 15mm copper pipe is now gone, and I have a 32mm MDPE line in its place waiting to be connected. (Terrific job to do last weekend given the cold weather by the way) I realised I have no idea what my pressure or flow rate will be in the house. I'm so used to cheap, rubbish combi boilers or the aging gravity-fed system that was present beforehand that I might be trying to fix a non-existent problem. So, the next steps are to get the pressure tested when the new pipe is connected, and then I can do a flow test off the garden tap to give me somewhere to start. Soon as I know those details I should be able to use the pipe diameter and distance to work out time to deliver for hot water and plan from there. Thanks all for your help so far, will update once I find out the pressure & flow and replan my piping!

Some good replies here - thanks everyone! Sounds like a satellite/remote/sub manifold will work for my situation, just need to KISS. A classic buildhub problem being left with too much time. This sounds similar in principle to what I'd be doing though I think. Two manifolds to "branch" in the further rooms and everything else off one local one. My main concern had been trying to keep everything radial. I think 22mm to feed remote manifolds with the HRC on the manifold via PIR or timer so the larger volume of hot water in the 22mm pipe gets circulated to mitigate that issue. I already have PIRs in place to activate the LED "pee" lights so you don't get blinded at night time so that could work...

Our build is coming along nicely and I'm getting to the stage where I lie awake for hours thinking about pipes. I've read plenty of topics on here about radial manifolds to reduce amount of water that needs drawing off for hot supply, plus also hot return circuits. I kinda want both, purely because I want the water to be hot quickly and I don't want to put in one solution and find it's not enough later. My problem is I don't think I could get an HRC on each radial leg without going totally overboard, so I'm thinking about satellite manifolds instead. I can put them in fairly easy-access locations in bathrooms so joints/leaks are less of a concern, plus I can run the HRC off the end of the satellite manifold back to the UVC. Is a satellite setup with HRC a wise idea? I can't see why having one manifold fed by a 22mm supply vs a few manifolds off a 22mm supply would be any different but I am not a plumber, just a hep20 enthusiast😂 A UVC will supply DHW, and the mains is being replaced from 15mm copper to 32mm MDPE, which means I don't know the mains pressure yet. I do know the HPPE was replaced in recent history so I am hoping the communication pipe is at least 25mm. (Keeping 32mm as cost difference is tiny and would rather not dig it up again later if water pressure drops in the area over time...) Picture for attention: I'm aware I'm missing lots of parts but as a "map" of what we're after hopefully it helps. The run to the family bath section will probably be 7-8 metres, but a big steel to support the opening stops me running all the individual pipes through and I'm looking for a "less is more" approach. The run to the master ensuite may be closer to 12-14 metres so would benefit from an HRC I think. Kitchen and the W/C is about 2 metres from UVC, and the utility about 4 metres. Layout of house (X is hot water point downstairs, triangle is hot water point upstairs) Thoughts?

Unfortunately I don't have any photos but you could visibly see the difference in soil; much more clay-like at the front of the house and it went sandy towards the back. I also forgot to mention that the underpinning on the side of the house is also where the water main went, so I had to excavate that by hand in a few areas and then bring it up out the ground to get it out the way of the piling and beams. It's rubbish 15mm copper, unfortunately (?) not lead so will have to be replaced at my cost rather than the water supplier. Pipe is currently 15mm JG stuff running on outside wall of the house, should probably deal with that before proper winter... Just waiting on a response if I'm allowed a 32mm connection to the meter or not. Other than that plenty of random bottles, and a brick road under the old driveway which had to be cleared by hand otherwise the piles couldn't get through it. They say budget about £1k per pile & the ringbeam to the next pile. Gives you a rough idea on the cost without me having to type it out (Not sure I'm ready to admit that to myself yet😂 ). We then also had the additional depth charge to add on and additional charges for labour the unexpected complications around non-shrinking concrete and the different foundation heights.

Welcome. Can't see your photo - can you upload again? Any changing of roof timbers I'd ask that question to an SE and let them calculate the load.