TerryE

BTW with an ASHP you have three different "grades" of water: potable; + inhibitor for the UFH loops; + antifreeze for the ASHP. You need to use PHEs between these; though I believe you can use a combined inhibitor / antifreeze mix for a combined UFH + ASHP flow, though no doubt JSH or NH will correct me if I am wrong.

Nick, I feel that you are missing a fundamental point here. The SunAmp uses PCM cells to get a lot of thermal capacity in a small form facts -- about 4½kWh in the standard box. The slab is a thermal store with well over 10x this thermal capacity at less than ½°C temp drop, and it is there anyway. IMO, there's little to be gained by using a SunAmp as a heat battery for the whole slab. Where is does make sense is possibly for a DHW preheat buffer, but really only when we have baths. I just tweak my version of the "Jeremy Spreadsheet" to increase the house temp to our actual average (21°C) and drop the Jan/Feb temps to actuals rather than forecast. So the prediction of this 3 year-old model was Feb average consumption of 47kWh / day. Our actuals this month vary between 42-55 kWh with an average 47.5 kWh /day , which I think is just amazing. It's bloody cold at the moment, the 24hr average temp is around 3°C so we are needing 21kWh @ low tariff + another 6kWh top-up late afternoon at peak tariff to maintain a warm house environment. This space heating element costs £1.51 (cheap) +0.83 (peak) (+5%VAT) at our current OVO tariff. Our slab could probably take more than 3kW, but I've only got the one 3kW heater. A big caveat for @Dreadnaught: for this sort of heating architecture to be viable you need to do the sums for your design and you then need to make damn sure that your house as built achieves the sort of passive class performance that you designed for. Acres of glass make a big difference to the figures; ditto bridging failures in the thermal envelope; ditto material airtightness failures. But get it right and you won't need upstairs heating at all, so no radiators cluttering walls, just a warn ground floor. This all being said, we'll be laying the insulated return pipe from the services room to the end of our garden shed (the probably place for ASHP should we decide to install one) this weekend as the paving guys are starting the drive and paving the following Monday. That way we won't have any digging to do if we do decide to install an ASHP.

We have got our completion cert yet, even though the house itself is done and we are living in it. We have some groundworks outside that are covered by the planning application and want to do this zero-rated -- which we can't if we've "completed" our build. I did ping my BCO, about a certificate of temporary habitation, but he didn't even bother replying, so we just moved in, and took out normal insurance.

Lizzie, quite a few of use have been caught by this: quite good initial terms but huge price hikes for extensions. As you say, it would have been a lot cheaper to buy the insurance upfront, but it's now too late to beat yourself up about it. The point is that a build insurance has to cover a lot of risks that you don't face in a completed house. We just transferred our standard house insurance to the new house when we moved in, because the build was finished by then. A year's standard insurance was about the same price as a 3-month extension to the self-build insurance. But don't do this before you've finished the building work or moved in because you might find that your insurer is unwilling to meet a claim in these circumstances. Have a trawl of the site. There's been lots of past threads on this.

Ian, first you turn the power off on that lighting circuit, then check it's off, then unscrew the switch from the pattras. Now you make sure that the surfaces are prepared according to your fillers instructions. Then do your filling. You will need at least two fill layers and maybe 3: a bulk fill, a top fill which you will level and sand when dry and maybe a touch up fill because you've notice a few hollows and you are a perfectionist. When it's dry to the touch, remove the crap from the pattras and refix the switch.

BTW Ian, there is always a hazard zone in the vertical and horizontal lines from any pattress. Like the others have said, a current detector is an excellent precaution, but drilling a hole in the wall directly above light switch is about as safe as sticking a screwdriver into an electrical socket?

I will expand this is Part III when I get time to post it including a fixed copy of that circuit @PeterW, but I am a bit busy at the mo. We've now been using the heating system for two months, including an interim NodeRED controller. I still have to put in an upper level of control, but at the moment all I am doing is having the Willis on 00:00-07:00 (our E7 slot) and a top-up of 2 hrs in the late afternoon. This leaves a residual ripple of around ½°C over the day (as @JSHarris has discussed previously), but other than that the house is amazingly stable. If the external temperature climbs to around 10°C then the house slowly warms up by about 0.1°C per day on the overall ripple, but for an overall average of 4°C or so, this small delta seems to wash out -- to the point that putting in any more advanced control algorithm just isn't a priority. As we get into lat Feb / Mar if it does steadily warm up then I might have to trim back the afternoon heating to 90 mins or an hour and by the end of March we should have stopped it entirely. But here is a typical day's usage: The two top hats are heating the slab. The other overnight spikes are the SunAmps, washing machine and dishwasher. The other base ripple is our general electricity usage for cooking, lighting etc. The main variation is the SunAmps -- you can tell if someone has had a bath because the spikes are fatter, and the type of cooking going on that day. So our total energy bill per day for our large 4 bedroom house is around £5, and this should fall to around £3.50 by end March and around £1.50 by May. You can see why the cost benefit case for adding an ASHP is marginal. One other point that we've realised: a "comfortable" temperature varies according to your activity level: maybe 19°C if you are working; 20°C if you are up and mobile; 22°C if you are sitting at a desk or watching the TV, etc.. Getting too hot is a real PITA because you need to start stripping off to avoid sweating; so we now keep the house at ~21°C dropping to 20½°C by the evenings, and there is just so much thermal inertia in the house that it's just easier to live with this so get the comfort by putting on a gilet in the evenings.

So am I, but I also have a not so little Jiminy Cricket who will let me know in no uncertain terms when I am moving in the Pandora direction so in this case my caution gets the upper hand.

Thanks guys. You are just juggling so many balls in the air during design and construction that you are bound to drop one or two. In this case we used 110mm pipe foulwater pipe as an access path from the service cupboard out beyond the slab. I mistake that I made was using a normal 87½° bend to bring it up into the service cupboard instead of a Drainage 87.5° Rest Bend, or even a 45° and cutting the stub off at an angle. The normal bend has a radius at centre of around 110mm and 160 at the outer curve. This was enough to get a 25mm MDPE DCW feed up the other access pipe. It's really touch and go as to whether installing an ASHP will be cost effective, and there's no urgency. I was going to wait until autumn when I've seen how the house performs during both winter and summer before making the call. The issue that we now face if that Jan is now in JFDI mode and wants to get all of the outside paving done by a local contractor including paving over the run where we'd need to bury the pipe. It's just not worth having to dig up a trench across the new paving, so I guess that the sensible thing to do now is to fork out the £500 or so for the proper insulated pipe and get our paving guy lay it under the paving whether we end up using it or not. Time get the 9" angle grinder out. I've got to clear the concrete perimeter up the pipe -- yes, I know that I should have left a length of ESP along the trench line and had the concrete about 25mm depth over it, but again -- a Tardis moment. PS. Concrete trenching all done and outside of access pipe exposed. A combination of a 9" Angle grinder with diamond disc and a decent SDS drill to put "stamp tear perforations" across the bit wanted to chop out made fairly easy work of it. As Jan pointed out, the reason for our JDFI (army acronym -- Just F***ing Do It) mode is that we want our VAT back as the paving plan was part of our landscaping and implementing is a planning condition so the work is zero VAT rated if we do it before sign-off.

Clive, just noticed this; you are a star, BTW. Ian, You shouldn't have cut the 3+E back to the same height above the rawlplug hole. Look through Clive's example again. You'll need to hack back further now. The joins need to be staggered so that no joins are at the same level. I guess this is a bit like asking Jan about her soldering skills, but you can use twisting the copper plus soldering as an alternative to crimping. You just need to strip back enough to slide the heat shrink beyond the hot bit otherwise it will shrink in the wrong place. And also wrap some wet cloth or kitchen towel around the heat shrink to keep it cool. However you achieve it, the end rest needs to be doubly insulated: once around each phase and once around the lot.

I did some research and there are four different model numbers but the only difference is on the reduction gears which determine how often the backflush is triggered.

We've also got a Harvey treating the entire potable supply. Works well. No more limescale; work surfaces, bathrooms, crockery, pans so much cleaner and easier to clean than without. The system uses a mechanical counter on used water volume to trigger the brine backflush, and there are four different gearings which sets the flush rate. My only slight quibble is that I suspect that the suppliers err on the salt heavy side in selecting the gearing. They certainly did in our case compared to the local Anglian hardness report. Higher frequency flush cycles mean less chance of complaints of residual hardness, and more sales of the salt bricks which aren't cheap.

Our had a low spot along one gable. It must have a whole 2-3mm lower that the rest of the slab -- enough to see the puddle when it rained in the 3 weeks before the frame went up. But on serious note, the guys made it look simple, but that because they were pros; they really knew what they were doing and were extremely particular. The tiler who slated the entire ground floor said that he'd never worked on a domestic new build like it. Fantastic thermal performance and really good VFM. I am extremely happy with my slab.

Ian, I hope that you have a stud/cable/pipe scanner. These should also pick up any pipe work near the surface.

@AndyT, at the moment I am running my house with the a Willis Heater for the UFH + 2 × SunAmp PV for the DHW. One option that we are considering is to use an ASHP for UFH heating / cooling and also for a §unAmp DHW preheat. The form factor of a conventional buffer tank might be an issue for us. If you did a micro stack -- that is a couple of PCM cells with a phase change of around 30-35°C and vacuum panel insulated in a form factor of the SunAmpPV. This wouldn't require any of the pumps, heaters, control logic of the SumAmp PVs , so should be a lower price item than the SunAmp PV and if so this might be something of interest to us. @JSHarris, what are your thoughts?

Most of us might have thought this, and isn't about time that someone invented the Tardis? You have to make decisions based on the best evidence at the time you make them. Others might make a different decision; you might do the same with 20/20 hindsight. We can't go back; only forward.

@Siochair, it's a good idea to search the forum before you post a Q on a topic. In this case, you will see that many members are early adopters and most of the points that you might raise have been covered in previous discussions. ?

I did a bit of project management in the IT world - enough to know the principles of good practice. We picked our major subs very carefully: a reputable TF company with good track record for the TF + slab, ditto for the windows and a good local outside ground works and stone skin. We also used some of his recommended tradesmen for trades such the electrician and plasterers. We used a local architect technician to help prepare the Planning Application, but other than that, I did all of the planning submission, the architecture and PM. Jan did a lot of the procurement online. I made damn sure that all of the interfaces between the subs were monitored and controlled, but in the first phase of the build we did as most have said: kept the site tidy, kept the troops happy, kept a fair watch on the quality of the work, but without getting in the tradesmen's way. If any tradesman has quoted a price then he or she has built in some contingency, if things run smoothly and they don't go past that contingency then the good ones will do a good job. What we also did was do pretty much all of the other internal 1st and second fix (less electrics, boarding out and plastering) ourselves. By this stage the house was secure and weather tight.This took a lot of our time and elapsed time, but we got exactly what we wanted to the quality we wanted and saved a stosh of money.

It's the arrogance and illogicality that really annoys me. Person A enters into agreement with company B to rent a car under which the payment is non refundable for a set of conditions detailed in X. Yet company B's position is that the eventual rental will by under a set of T&Cs Y, so if the company B decides to deny the service to A because of a failure of a condition in Y (which A hasn't yet agreed to), then B feels entirely entitled to keep the money. The second point is as Jack says. Avis/Budget have now gone paperless, so Jan was presented with an on-screen rendering of a PDF document that she was supposed to read (by doing repeated page down) and then sign at the bottom. "Don't worry we will email you a copy of the signed PDF", said the desk agent. In other words you either stand for 20 mins in line or alternatively only get an opportunity to read the contract once you have signed it. And by the previous logic, if you don't find the terms acceptable you lose the money anyway. The phrase "bunch of crooks" comes to mind.

This is really a bit of a rant and lessons learnt. First of all our 04 Volvo S50 Estate's clutch is going. Lovely car; bodywork and comfort excellent, but the engine has done 150K miles and is getting clapped out. So we needed a hire care at short notice and choose Budget, and paid online. An hour later the "Oh shit" moment: we'd sent our licences off to the DVLA to get the address changed when we moved in to the new house. They hadn't arrived back yet. So Jan decided to try a photocopy of her DL and passport as they often do an online check of the licence anyway. No good: a hour later she returns. A quick check of the "Booking Terms and Conditions: Please see the Booking Conditions for more details on cancelling your booking, the associated charges and how to claim any refund you may be entitled to" and also through the booking dialogue; this was the only T&Cs that had agreed to. This only states that the renter must hold a current DL, and doesn't state that she or he must present the original. A call the customer service number: Can we have a refund or part refund? No. Can you explain where in the agreement that entered into online that my wife had to present her original DL? No, it's in our General T&Cs. OK, you asked me to confirm the Booking Conditions, but can you tell me where on the website or booking process you make them available for inspection? No. You get them when you pick up the car. So you are using a document that you haven't given me and can refer me to as a reason to refuse a rental and them you are with-holding refund for reasons that lie outside the agreement that we entered into? You wont get you money back. This is a non-refundable booking. Will you please confirm this in writing? No OK if the DL arrives in the post later today or tomorrow say, can we at least have the car from the remainder of the term? Unlikely, but you need to check with the local office. If the customer doesn't pick up the car at the agreed time then it is normally reassign for hire. I managed to remain polite and rational through all this, but I was steaming by the time I put down the phone. 15 mins later the post arrives with Jan and my DLs. Another call this time to the hiring desk: We were refused pick of a car this morning because not having possession of an original valid licence. It's now turned up, will we still be able to pick up the car? (This is at 13:30 when the scheduled pick up was at 11:00) Yes; cars are normally held on the same day. But you say that you've just changed your address? Is your address on the DL the same as on the Electoral Register? No, we've only just moved in. In that case you will also need to bring two bank statements official letters proving that the driver resides at the address. Where does it say this? .... As it happened the lady at the desk didn't ask for the proofs that Jan took with her just in case. So we now have the car. Two lessons from this: Be aware of the pitfalls of changing address. Yes you need to do it, but stagger things like changing DLs, just in case you get stuck in a denial of service. If a company has preconditions for the sale of a service then it should be upfront and clear about these -- say as a simple checklist before you buy the service. Any company whose position is that they can sell a a non-refundable service under T&Cs that they don't make available to the buyer before or during the sale are dishonest and possibly acting illegally. IMO, Avis / Budget fall into the category, and I would never use them again.

Well we drove up to Manchester and stayed overnight then went to the English Sofa Company factory / showroom the following morning. Jan and I were far from impressed with styles and even more so with the (lack of) quality: the leather seaming was crude and untidy; leather on the display items was sometimes pulled / strained and the designs were uncomfortable to sit in. So after 30 mins in the showroom, we took our leave and headed south. On the way back I had a look on Google maps at where the sofa shops were in Birmingham and Coventry, but we decided that they were just too dispersed to make a "shotgun in the dark" stop-overs worthwhile. I then checked MK and discovered that all of the main sofa shops are in one mall square. So back to MK, and after a few tries we ended up in a shop in the square that isn't even listed on Google: Natuzzi: Italian and extremely high quality in terms of comfort, style and attention to detail in the finishing -- albeit expensive. However after the ESC and the other showrooms, both Jan and I felt that the Natuzzi stuff was just in a different league so we decided to bite the bullet and pay for the quality.

Yup, we'd never buy a bed or a sofa without making sure that we like the style and comfort "in the flesh". It's just that N'ton <-> Manchester is a bit of a shopping trip!

We are looking for some nice furniture for our new living room and are struggling to find suitable suppliers of comfortable and functional furniture. We've looked at the usual chain suppliers such as DFS and Furniture Village, and in my view their ranges (or at least the ones we looked at) just aren't to our taste. We like the sofas from the the English Sofa Company, but I am interested if anyone can recommend alternatives. We live near Northampton and the ESC is in Salford which is about a 6 hr round trip if we want to try any out.

I can't remember where I got mine from. Just Google magnifying headset with light. Theother thing that I would recommend is a temperature controlled iron. You can get a cheapy from Bangood or AliExpress for around £30-50 if I recall. They are size compatible with the Pro ones that cost ten times as much, which means that the cheap tips also fit them.The temperature is usually way off calibration, but you just work out the setting that works for you by trial and error. A lot better than any uncontrolled iron, and good enough for doing the odd through hole board. Big Clive did a review of one on YouTube, which is what made me buy one.