TerryE

@readiescards Mine is 100mm with extra 200×200 bracers every 2m and a 300×300mm ringbeam and ditto 2 loadbearing cross-members so you have ½ the thermal capacity / sq m. how many sq m in your GFL, because your curves are going to be a bit steeper than mine?

This is what my Spakie said, but he also said that the regs didn't specify where between the CU and the meter this had to be positioned, so we have ours next to the meter on the same board. but he also ran SWA from the CU to the isolator. I had to put the ducting pipe through the TF at 45° or we wouldn't have been able to make the turn within the service cavity depth.

While I think on, IIRC they have a nominal maximum rating of 6 bar, but I run my UFH loops at 1 bar.

In the typical installation which is external heat for an indirect HW cylinder they are fitted vertically as the thermal gradient is the primary pumping action. In this case the thermal effect is trivial compared to the UFH pump so that can be fitted either way. You can see all of the ds18b20s in this figure, plus the PHE. The typical delta is -5°C out -> return at the manifold and 10°C return -> Willis top so the water flow is ~50:50 through the Willis and the PHE. The 5°C is at the medium pump flow setting. At high setting this drops to ~3°C. but I am happy with 5°C and very little pump noise. BTW, if you want to use the out/returns to measure the slab temperatures then you need to run the pump for 5 mins first. @readiescards, I am happy to talk through all of this stuff with you, but give it 3 days or so because I've had an absolutely shitty cold for 3 weeks and still can't speak easily. Also like Jeremy and others, I do offer an open invite to forum members to come and to see my build and to discuss any issues that they want. Lincolnshire to Northamptonshire isn't that far. If you want to do either, then just PM me, though can you give me your email addr because I prefer using email.

as @Dreadnaught says I have even described all this in my blog posts, so all you need to do is to read this, and ponder what I say. Make a point of reading the referenced posts which go into a lot of detail including my mathematical simulation of the system to determine its operating characteristics so that was I confident that the system would work this way before I implemented it (and the first commission tests validate the model). We have this as our sole source of UFH heating and at the moment we are at a comfortable 22°C with a ½°C ripple over the day using 17½kWh of heating at E7 for a large 4 bedroom passive class house. Hence my recent post: But to your specific Qs: Does it need an additional expansion vessel adding to the system? It add an extra ~1ltr of water in the UFH circuit, so No. If I install the device just before the UFH manifold, would extra valving be essential to prevent the UFH pump running the return water through the boiler circuit all the time? Again read my posts and have a look at the photos. I have my Wilis effectively on a 15mm bypass across the UFH loop with a PHE on the other branch. No valves, but the flow runs roughly 50:50% through the two branches. That's on the warm loop side in a boiler mix-down implementation. I don't have a boiler, so my TMV is just cranked open. It is entirely redundant and I've only got one because this was the cheapest Wunda config that suited my needs. If you read the physics of this then you will see that this isn't an issue. I have a BS1820 temp sensor buried in the slab, the control circuit seems simple ... Have I missed something? What a bizarre type of sensor. A lot of people do this and for the life of me I don't understand why. I've already got this remote sensor which integrates the slab temperature by UFH zone: the UFH flow loops. I have ds18b20s on the out and return of each loop. Simpler, easier and a simple way to balance the flow through the loops as well. OK, so I have lots of ds18b20s measuring just about everything, but at £1.50 each this is hardly breaking the bank. On your supplementary points: If the UFH pump failed the Willis unit dual thermostats will cut in and switch it off. Eh?? This isn't a failure point; it's an essential backup safety feature. If the slab temp sensor fails the floor could get too hot so an extra temp sensor on the manifold could verify the return UFH water remains within acceptable limits. Yes, which is why you should always monitor your flow and return temperatures and include cut-offs in your control system. If you are too mean to spend the extra ~£6 on doing this per loop, then by all means do it on the manifold out and return. I am not sure that you are using for your automation system but your inclusion of Javascript-like pseudo-code suggests that you are reasonably IT literate. My HA is based on a single RPi3 with SSD running Node Red. All of the IOs are done by two (soon to be one) ESP8266 modules USB-serially attached to the RPi (so the core DHW + CH system is independent of our Enet Hub + Wifi). I do use other WiFI-connected Wemos modules for nice-to-have remote sensing. I run the NodeMCU Lua subsystem on my ESPs and talk native json to Node Red, though I also run and use a MQTT broker on my RPI. The support that I get on the Lua system is excellent (but that's because I on one of the core developers on the project ). By far the most expensive bits in my system are the 4×Crydom SSRs, but that's so my sparkie could sign off the 240V side and keep my BCO happy. The rest cost < £100. Not a virtue; just no point in spending any more. Yes, it has involved a lot of personal time, but it's my hobby project, and my son-in-law is into all of this shit as well so he's my SPoF backup.

As opposed to an annoying southerner now living in Devon, or is it Cornwall?

In England, the Land Registration is what it is at point of registration and the boundaries are what they are unless varied by a court order or by agreement with both parties. In the case of our previous property, there was a path along one side. The first deeds of sale in 1913 specifically discussed it as part of our property, but when our neighbour's nephew sold her property in 1994 (by that time registration was compulsory) the registering solicitors submitted a site plan to the LRO which incorrectly claimed our path. We didn't know anything of this, because we weren't consulted, and none of the neighbours noticed this mistake because we maintained the path and fence and you could only get to it from the public highway or our property so it was obviously ours. When we discovered it in 2015, the LR refused to accept that the original registration was in error, and in the end we and our neighbour had to jointly submit a TP4 to transfer the path back to us. There are two methods of registering a boundary: Use of OS National Grid co-ords, but in this case you need a properly qualified person (e.g. a chartered surveyor) using OS approved survey equipment. Use of measurements from permanent features, and IMO this is the simplest and best way: nice straight lines between permanent boundary markers, such as short concrete spur posts concreted into the ground and photographed in location. In your case, I see nothing wrong with walking the new boundary with the seller and staking, marking and taking a 3-way selfie (you, the seller and the rebar in ground context) at the way points, and proceeding on that basis, maybe with the pre-agreement that you will replace them with by permanent markers with 6 months of the sale. You don't need tape between them so long as the boundary between markers is straight, as line of site will do fine. If you do a "roll-your-own" survey, then how will you ever prove that is was accurate if you need to? No, OS grid coords = paying for a CS, but you still need permanent markers, IMO

Ian, I half wish you wouldn't do this. The problem is that when I click on on of these links I end up watching the next 3 or 4 entranced -- and then the next time I log onto YouTube, half my recommends are videos about Fred or demolishing chimneys. Characters like him are gems and I still think of him fondly even though he's been in the ground for over a decade, but in return I will give you a monologue from another such character which I first read in a John Julius Norwich anthology from Blaster Bates: The Shower of Shit over Cheshire or the YouTube soundtrack version.

Good (relating to the scope of the development) purchased before the sign-off date for the purposes of completing the development clearly fall within VAT reclaim category. My pint is that we were very much cash constrained towards the end of our build, so we deferred any non-essential expenditure until we had sold the old house and moved into the new one. That being said, the deferred stuff was not trivial: glass doors on en-suites, fitted cupboard doors, all of the external landscaping works. Delaying BCO sign-off after this has save us maybe £4K so far.

Lizzie, there are two separate facets here: Between you and your BCO, and specifically when you've got the point were the BCO is willing to issue the completion certificate Between you and your HMRC inspector. AFAIK, you can't reclaim VAT on work executed after you have received the completion certificate. In our case the LPA insisted that we include planting plans, restoring road frontage, etc. in our conditions. At the time, I thought that this was a bureaucratic PITA, but I later realised that by bringing all of this stuff within the scope of the application, they were actually doing us a favour: this work comes within the scope of the development and is therefore reclaimable. Driveways, electric gates, landscaping ... can easily end up costing more than £20K, so delaying sign-off might well be worth while if you can avoid VAT on this.

Mike, I think that you are excusing corporate or systemic incompetence. Issues of trust and risk need to be tempered by an assessment of the consequences. You are getting hosed about 30 min fire risk in a single dwelling, one in which the self builder is proposing to live in and as nod says 12mm plasterboard + a skin will give more than that in most circumstances. Grenfell Tower had 120 flats. The 71 confirmed deaths and the total number TBD had a single exit route which had unprotected gas pipes running along it. I am not blaming the individual LA BCOs because I do think that they have a thankless job, but I am challenging the systemic environment and management policies which -- in my view at least -- mean that they can't put their focus where society needs them to and instead have to vent their frustrations on individual self-builders.

Mike, what I find crazy about this is that you get this 20/20 drill down into all sorts of fine detail about your build -- where I am absolutely sure that in reality you are conforming to the spirit of the BReg and far more on the letter than any typical major constructors dwelling build (you are after all putting your lives at stake in getting this right) -- yet we can refurbish tower block like Grenfell and have copper gas mains without any fire protect in safety corridors where the live of 100s of occupants depended on their integrity, where their claddings were death waiting to happen. Yet all unchecked. Where is the sense of proportionality?

I don't spend a lot of time in the shower washing my face, and I don't use bar soap.

I remember an old friend of mine -- who died 6 days before his big 90th birthday bash -- asking my what was the point of quantum mechanics. He'd read a number of introductions to it and just couldn't understand what it was all about. My answer to him was that it was less important that he understood it. The main point was did he use computers, mobile phones. the telephone, modern drugs, modern fabrics and materials, ... None of these would have been possible if the people developing them had been limited to classical physics; the relatively small numbers of scientists and engineers who are transforming our society and the quality of everyone's lives need to understand this stuff to do the magic that they do. I realise that Hawkins attempted to popularise what he is doing, but the important thing here is not that 10% of the population understands or remotely comprehends this, but that the tiny percentage of people who need to do understand. The domain where Hawkins worked is at the boundary where general relatively meets quantum mechanics --two theories that explain the physics of our universe to exquisite precision, yet are mutually inconsistent. Maybe we don't need to understand all this, but also perhaps the scientists and engineers that will build a workable fusion energy source that will transform the plight of humanity going into the 22nd century do.

Hawkins was an atheist who was publicly open about this, but for the large part only commented on this in a personal context. Of far more importance was that he was also a great scientist and thinker who achieved this greatness despite personal tragedy and disability that would crush the vast majority of us. He left the world a better place after his passing and caused no material harm to others in doing so. If I could achieve 10% of that, then I would die happy.

USB3, extra RAM and SATA would be good. The SBCs that have these are about the same price and are a far better for a SBC server.

Nick, google ESP8266 Tasmota or Sonoff Tasmota. Sonoff use the ESP8266 as their standard controller and this in an Open Source apps platform designed to run of the sonoff kit and RYO ESP boards. There are also anther couple of Open sources apps tiers based on MQTT. Just run an MQTT broker and NodeRED on your RPi and let MQTT do the connection magic. They support a range of OW, and I2C devices. Or use MicroPython or NodeMCU Lua if you aren't comfortable with the raw Arduino support. Lot's of options if you are willing to learn.

Members who have used a given company can talk in detail about that company. What I would like to see is more members who have used other companies explain the values and advantages of the alternatives. Someone has to generate that content. That's what this thread is about.

[ Edited in line with other edit above to remove dead quote. ] There is a view recently implied or expressed by some members that the forum is pro-MBC, to the exclusion of other TF alternatives. Yes, some of the active contributors including myself have been open about having MBC timber frames in their builds and have blogged and posted about our experiences. I just wish that members with other TFs would put their experiences and recommendations into print so that these can be mined by new members. I started this thread to encourage other members to present such a balanced set of alternatives to new members, but I can't create this content.

@IanR, any updates on how it is going and lessons leant? This would be a great addition to this thread.

Thanks @IanR. That's link is an extremely useful cross-link for other readers :-)

I am really just refreshing this topic to let members other than those who have had an MBC timberframe have an opportunity to recommend / give feedback on their supplier. The problem we have as the main contributors is having other members give constructive recommendations on other suppliers and whether they would recommend them etc. @IanR, @NSS and @RandAbuild, I know that you are both active on the forum. Any comments? Can any other members suggest who else might want to give input?

I would have been tempted just to bung the insulation block into the hole and foam it into place, and with some drizzle foam zig-zagged on the front to act as a keying surface. Then when dry, tossed in a snotty mix and tapped the front Durisol plate onto it and banged a few 6" nail through to keep it in place, whilst the snot went off. But liquid does tend to flow through holes unless you plug 'em.

Our planning department turned down the installation of PV in our pre-planning advice: PV on the principle elevation was "not in keeping with the preferred cottage style". The house is SE facing, so the principle elevation is the only one where it makes sense to install PV. So we use grid electricity for all energy (apart from a couple of back propane gas rings on our cooking hob, just in case of power cuts. Our village has a wind-farm and 3 largish PV installations within a 3 mile radius, so we it makes sense to buy our green electricity through the grid. We've learnt so much from Jeremy's experience, but he's reworks his system at least three times, each a stepwise improvement and he isn't living in his house full time yet! So our intent has always been to use the 1st year to complete the house inside and out and gain experience of living in it (including collecting hard performance data on the house as built) before doing any optimisation of the heating system etc..

@Dreadnaught, we live at NN7 so you are close enough for you to come over for a visit and walk around / talk some of the issues. Just PM me if you want to. I am sure that other members can do likewise. I know that I've made this point on other threads, but the devil is in the detail on ensuring that the house as-built achieves the as-designed goals. We are retired and our build was on an adjacent plot split off from our previous garden -- and so we could keep an extremely close eye on all of the quality issues. This isn't the case with people how have to hold down a job and don't live next to their build. Here you have to put a lot more trust in the trades teams. Doing a self-build is extremely stressful , IMO and having a bad builder or tradesmen cut corners is the last thing that you want to face, especially if you only find out when it is too late to fix the issue cheaply. So my view is that you make damn sure that you pick the right builder / supplier with an excellent track record. As to my "bath" point, I don't use the Willis for my potable hot water at all, just the slab. I have a pair of SunAmp PVs which I heat overnight. This is absolutely fine for normal use, but we have a big bath and a full one on top of normal daily use is enough to require use to top-up the SunAmps after this with peak rate top-up.