Thorfun

that's great to know @JamesP as I've been looking at those F-line systems (as well as the Rain Sava systems). how is the F-line system? you've gone for the same sizing I'd be looking at in the F-line series. why did you choose the F-line over a.n.other system?

interesting. how long did the pump last?

cool, so yours is sized so that it will overflow occasionally?

ps. was told that the RWH tank needs to overflow occasionally to 'wash away' any pollen that could cause a sulphurous smell that has gotten through the filter.

I've been recommended a 4500 - 5000 litre tank when taking in our roof size and average rainfall. we will have 6 toilets in the house (obviously not all of them will be used at once!) with a regular occupancy of 4 humans (the dog and cats don't often drink from the toilets so that will save us some water). will also be used for washing the car, watering the veggies etc and thinking of potentially using it for the washing machine but will need to do more research on the potential pitfalls of that one. thanks for your opinion on not needing a header tank. I'm leaning that way, especially as it's about £500 extra for the gravity system and that's before the extra plumbing required. and for the money saved I could replace the pump later on down the line if required and still be quids in.

got another question about RWH and thought I'd keep it here rather than start a new thread. Direct vs Gravity? I can see pros and cons for both, here's a basic list that I can think of although I've probably missed some obvious ones. Direct fed Pros: 1. no header tank 2. cheaper 3. reduced risk of Legionalla 4. reduced plumbing complexity needing to run extra pipework to a tank in the loft Direct fed Cons: 1. pump runs every time a toilet is flushed 2. slow drip leak from a toilet will cause the pump to keep cycling to compensate for that small leak 3. a low RWH tank level will result in mains water filling the RWH tank rather than a header tank in a gravity system (at least I assume that's how it works) I guess the Gravity fed Pros and Cons are pretty much the opposite of the direct fed ones. Now, I know on here folk don't seem to think that RWH doesn't make sense financially but we really like the concept and reducing our reliability on the main utilities where possible. we also think that we can incorporate the cost into the total build budget. so with that in mind, would you go direct or gravity fed RWH and why?

well done! you managed to get her to buy you a shed. she sounds like a keeper. ? as long as she doesn't change the locks to the house while you're 'working' in the shed that is.

can't the wife be put outdoors instead?

I think our dog must be a bit spoilt as we're building a 'doggy shower' in the utility room for him.

Fair enough. Can’t help with the question about potential issues but I do thank you for the heads up about lack of frametherm 32!

if you haven't signed the contract with MBC yet have you thought about approaching another company? or changing to their blown cellulose twin-stud wall? are all other manufacturers struggling to get Frametherm 32? it's what I want to install in my open-panel timber frame so maybe I need to start sourcing that now!

thank you for the photo. they look really good. nice to see that it's not a uniform print on each tile.

thanks for this comment @Christine Walker. it's nice to get a positive opinion on them. don't suppose you'd be able to post of photo of them would you please?

thanks @ProDave. interesting information.

thanks. I'll do a search on here for other's experiences of them.

We were just looking at this very thing this evening. do you have first hand experience with them? Is it obviously a repeating printed pattern?

not ordered it yet, not even broken ground yet! but we got a good quote from https://shousugiban.co.uk and the samples looked really good. but, nearer the time of ordering I will get further quotes from other companies. we're having a combination of the charred larch and normal larch to get the brown/black contrast in places. hopefully it should look lovely. ?

our architect recommended this https://www.dupont.co.uk/products/tyvek-uv-facade.html as a breathable membrane below our shadow gap cladding. it doesn't have any logo or markings and comes with a 10yr warranty. might be worth a look? I've asked our TF company to use this instead of the shiny silver membrane as we don't want silver showing through our charred larch cladding shadow gap! I looked at the Protect version but that has 'Protect' in red on the outside and also states the 5000hrs only with no warranty. I think that the 5000hrs refers to the BS standard for accelerated testing of the membrane though. but don't quote me on that. so it's not to say that it won't last more than 5000hrs but has only been tested to 5000hrs. if that makes sense? I'm sure someone more knowledgable than me on all of this will be along soon to refute or confirm what I've said. ?

thanks @joth. this is great information. Enhabit are certainly top of my list at the moment for MVHR. I'm currently debating whether to get them to design the M&E or getting the relevant trades to do their individual bit, e.g. the plumber to design the heating system, solar pv company to design that, Wunda to design the UFH etc...

this is interesting. I was quoted £1100 +VAT for just the MVHR design from them and the Mechanical Service Design is £1500 + VAT! (PHPP modelling was also £1500 + VAT) your negotiating skills must be top notch (or mine are just s%*t ?‍♂️). but, in saying that, their quote for the hardware for the MVHR is very competitive and seem very helpful on the phone so they're still a consideration for me. I guess sometimes you have to pay to get good quality information and design as I can't do everything myself. at least not if I want to be in the house before I get so old I can't walk up the stairs!

that all looks very interesting and exciting! please keep us informed as to how you get on. I will be following with interest.

thanks @joth. I have no specific units in mind for anything yet! still on the research stage. I'm tempted to run pipework to multiple locations and just cap it off and then when I decide if/how to cool then I can pick the best place to do that based on the unused pipework in place. eg. I could put an AC unit (or fan coil I guess) in the loft and run a duct to the vaulted entrance hall like @Jeremy Harris suggests he'd have done it. or I could run a duct cooler with the MVHR in the plant room. so I might as well insulate the supply ducts and run a few copper pipes to a couple of locations....all just in case! still have loads of research to do on this and many other subjects! I look forward to reading about your exploits in this area.

if I may jump in on this thread and ask my own question? I have a friend who is about 3 months ahead of us with their self-build. they've had their MVHR installed and the ducts all run inside the insulated envelope, yet I noticed that the installers insulated all the supply ducts to the rooms. I assume that's because they have a 'cooling' element to their MVHR system? we are planning to plan for the possibility of using a fan coil/duct cooler fed from the ASHP to potentially add a cooling element to the MVHR if we require it a couple of years down the line. so I assume that I'd need to also insulate ALL the supply ducts to every room in case we do go down the cooling route? but if we don't need a cooling element with the MVHR then insulating supply ducts when inside the insulated envelope of the building is not necessary?

only assistance I'm able to give on this one is when I was researching internal sliding glass doors I found the ID systems ones that looked good. https://idsystems.co.uk/glass-partitions/ were pretty expensive though! I have no experience buying from them though so cannot give a recommendation for the doors or supplier but I believe that they have a pretty good reputation.

this is true! I am still toying with the idea of just using 50mm PIR (or somewhere in between, maybe 70mm) but the building control drawings are being done with 80mm PIR and the SAP calculations as well. so I'll probably just stick with that and deal with the screws as and when I get to it. I based the build up on the MBC wall as well as many other companies' designs...