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Yes, an extractor to the outside. It's through a gravity flap which has a rubber seal on and is pretty airtight, certainly not entertaining any backflow. It will very rarely (depending on wind direction) flap open briefly on very heavy gusts and so I've considered going to a motorised damper, but it's just not bad enough to really worry about...

That rather depends on particular circumstances. Here solar is crap from the beginning of November to the middle of March. Dorset is pretty far south so will have better insolation than most of the country and individual location has a significant effect on energy availability. Over sizing is not really a solution; if there's low insolation levels you won't harvest much energy however large the array. Ours is over 14kW peak and still produces next to nothing in the winter. Yes, panels are cheap but most people have limited space to put them. We've used all the available roofs, and I'm going to ground mount an extra 3+kW, just because I can; it won't make a meaningful addition to the energy produced in winter.

But you can get some good days, although quite short. This year we did Christmas day on boxing day and our lunch was all cooked via solar. The yellow is solar generation, green consumption, and blue below the zero line is battery being charged. The red is import electricity. We get a texts - do you power? we answer yes, but the mains is down, similar the other days mains water was off, but we use a borehole.

Re: reusing the slab - you’ll want to allow for a bunch of insulation (anywhere between 100 &300mm) and check you have enough foundation strength there to support a house rather than a shed, so it may just be easier to re-make the slab. That also gives you more design flexibility if you need it. I vote also for a build schedule / financial arrangement that doesn’t leave the builder with the body of an 80 year old

Why... I'm just trying to help keep the forum quality high? Op has repeatedly been creating posts with the title as their username despite others already asking them not to. I figured I'd help them learn how to use it properly with a quick screenshot?

Not sure they recommend that

Sorry folks that number was pulled from memory - and was clearly wildly incorrect. The average window U-value is 0.9 (Rational Auraplus, Triple glazed, magic coatings etc.) The house is South facing, Coastal and Northern. Overheating has not been an issue while we have lived here. Salt deposits on the windows provide all the shading we need 🙂 Not sure how PHPP handles this.

With the EPH controls you don't need to change your valves as it's managed through the controller wiring. So the 2 normally closed valves stay in place. Not on its own it doesn't. It needs the option diverter kit which has the dhw cylinder sensor - this is what gives you 2 flow temps, but for boiler modulation you then need the Easy control or weather comp.

I’ve a couple of these machines and we use them on a weekly basis Mine are both aitechs But speedy to two different ones Get the larger Get it all marked out prior to hire and you will easily do 85m2 in a day Don’t forget to hire a 30 amp transformer and lead

Believe so

There is nothing wrong with recirculating cooker hoods. But if you can easily have an airtight, automatic cooker hood venting outside, why wouldn’t you? For me this is similar to the issue of MVHRs sucking in bonfire smoke. Not an issue for many, but not something you want to suffer if you don’t have to. Part of the joy of self building is that you can indulge certain preferences that may not pass a normal cost benefit analysis. Nearly all the reading I did on MVHRs pointed to recirculating cooker hoods as the solution for cooking vapours. But there are some interesting dissenting voices. https://www.treehugger.com/passive-house-institutes-look-kitchen-fans-less-exhaustive-4857372 Here is the Passive House guide on kitchen ventilation. https://passiv.de/downloads/05_extractor_hoods_guideline.pdf

We have PV GivEnergy all in one. If battery is full and I start to export this picked up by the PV diverter and that electric goes to the immersion. If I was to get an electric vehicle I would just get a GivEnergy charger, then you can control better how it all works together.

Nothing technical wrong - you gain a max of 5mm compared to PIR, but at the same time state to use a 45 to 50mm packer. Your money, your house, just trying to save you a few hundred pounds, on wasted materials.

Only if the beam contributed to the overall stability of the building, if it just supports the roof then no fire protection is required.

Historically a single 2+E has been run down to switches. The blue (Neutral) wire in this is sleeved brown and used to provide switched live back up to the light fitting. This means there is no Neutral wire at the switch. Most dimmers don't need a Neutral but I think some home automation devices may require one. I'd use 3+E. An extra wire is also needed where you have two way switching (two switches controlling the same lights). These switches need Live, two Switched Lives and possibly a Neutral. Total 4+E, normally done as Two 2+E ?

You have 10mm of aerogel, PIR with the same R value is between 13 and 15mm depending on its spec. And you are adding 40 to 50mm packer, the packer is providing 3x the thermal resistance of the Aerogel - so why bother with the aerogel, just use PIR, it cheaper, easier to work with.

The panel layout will be interesting and there will almost certainly be shading issues. So, microinverters on all the panels (Enphase obvs). That's going to be a bit more expensive to start with but more reliable and cheaper in the long run. Probably Victron to charge the battery and maybe Fogstar for the battery. Eddi for the immersion and I believe that can cascade onto the Zappi. Some thoughts to juggle with anyway.

I popped a email to WB, they inform that..... "The blocking code 2965 is generated when the heat exchanger temperature is greater than 88°C." So irrespective of TRV settings or whatever, once the heat demand is less than the boiler's minimum output then if the target flow temperature is set to 82C then it is almost inevitable that the temperature will reach 88C since all gas boilers don't trip the burner until the flow temperature reaches target temp+ (at least) 5C. This setting is far too close to the WB approved max flow temperature setting of 82C. I will now pose the question to them of whether there is a delay in clearing that alarm if still up on c/o to DHW.

Second reason is for multiple switching of banks of lights. You can have two rows of spots switched separately from one cable. Helps reduce the number of wires if youre looping in the switch! Just gives you options for an almost identical amount of work and cost

We have a vent axia kinetic something, and I ran a controller (linked above) to main bathroom, to enable me to fiddle settings without going into loft. The lack of back light is a piss take for the cost, but it does the job. I then installed rocker switches in each bathroom, and wired the cables back to MVHR itself. I ran 4 core as I had spare, but it only needs 2 core to make the connection. Means if guests/fam go to the loo and want to, they can manually enable boost!

The only reason you might want 3 core is if you plan to have a light fitting that needs a permanent live, perhaps it has a sensor for automatic operation? or perhaps you want a light and fan? If you are certain it will just be a light controlled from the switch on the wall then no need.

Plus one

The joy of City Plumbing is that it is free delivery. Bimble passes the total cost of delivery on m, which varies up to £210 for a full pallet.

I have this model of mvhr and was initially prepared to wire a wireless relay to boost it based off a humidity sensor in bathroom etc . The reality was ; as the run ( deliberately ! ) is very short to bathroom and ensuite it automatically boosts itself within 30 seconds of a shower / bath . So I would ‘allow’ for wiring to boost it but in practise may not be necessary.

success, looks like it can. Just need a switch or two.

My first array is at 45 degs and roof mounted - dreadful output in winter, not helped by trees and low sun. Our second array is ground mounted, but vertical, provides 200% the output of the first array in winter.

Well I suppose this thread has run it's course then. You know the issue, unwilling or unable to change your ways. The other option is to throw the consumer protection option of "it's not fit for purpose" flag and demand its fixed by the installer, he would then get the manufacturer involved formally. Sitting on your hands, saying I know the issue and procrastination doesn't fix anything. Running high temperatures with lots of trv's doesn't help either. I will now bow out of this thread.

Really would you waste your money on aerogel and the then support it with PIR. The PIR on its own is doing the job. 10mm Aerogel is really adding nothing to reducing the thermal bridge. Just use 60mm PIR or deeper.

Our unit uses volt free momentary switch and it starts a rundown timer. But once the house is dried out, you really don't need to boost. Something smelly in the kitchen we boost, and maybe when having the annual bath, don't bother after shower.

@Jenki I've followed some of your posts and on the back of your experiance I contacted Will at Polysteel. Their office is a 5 min drive from my current home, so i popped round last week and had a chat. I like the product but was a little concerned by the office/business and the lack of people. This to me would indicate a risk of lack of support ? I'll have to factor that in when making a decision on which system to go with.

Mine is a little different in that in has 4 selectable speeds, and I use one of the faster ones as boost, but the principle is the same. I use 2 of these, one upstairs, and one downstairs. https://www.tlc-direct.co.uk/Products/SMSTBT4.html They are meant for powering an immersion heater so have a 13A switched 230V output. In my case I use relays to switch my volt free contacts, but if you have an option module that accepts 230V switched live in, it should connect straight to that. One is in the kitchen to boost the mvhr when cooking, the other is on the landing to boost the mvhr when showering. I didn't want it on the lights, you don't want to boost it every time you go for a pee. For wiring, a 3 core & earth 1mm from mvhr to the boost switch is all you need.

No surprise that UK houses are generally poor compared to every other developed country. It does mean a good self-build is light years ahead of just about anything else that gets built.

I use www.archive.ph to get past paywalls. Copy the link of the restricted article and paste into the search bar in archive.ph. If archive.ph is taking time to open try turning off your wifi and use mobile data only (assuming you're using your phone).

Happy to explain these issues to you. Its long winded and if's and buts involved. Feel free to call me (phone number removed) (admin - remove if unacceptable)

Plant the stones and in a few years you can be harvesting your own crop (I have a few planted in pots and may plant them properly one day).

Or eat too much Avocado! I had some elderly relatives lived in one of the Wandsworth pre-fabs and they said they loved it and he was a construction professional - structural engineer. I stayed there for a short while when I was about 8 and had a great week - some of the kids in the street still lived in bomb damaged houses just along from it.

Bog-standard (but powerful) extractor, and MVHR extract point over the sink but near the cooker. Normal steamy cooking is dealt with just fine by the MVHR, but on the occasions that I want to fry or stirfry I whack on the big fan. Ensures the oils aren't heading into the ducts, and I really don't care if flow is unbalanced for half an hour every now and then...

Because of the designs used, they were perceived as temporary caravans/beach huts. I have an American mate who worked in an architects office for many years (did the model making/photography) and when she moved to the UK she heard the term "put all your money into bricks and mortar" for the first time. She still finds it an funny saying and often says it when conversation about our class system crops up (which is quite often when an American is in the room). We seem to have designed a housing system and sell it as a privilege to be a home owner, if you cannot get on the housing ladder it is because of personal failings i.e. you own a phone, have a coffee in a cafe.

Yes Berkely Homes has also closed its very hi-tech factory in Dartford because it cannot make it pay, and they are volume house builders so industrialisation should be a natural progression. How come we managed to make this work in the 1940's but seem unable to make it work today with all the advanced technologies that could be applied.

At least one has you, at least, owning the materials before delivery. That’s some protection although how well it works in practice I can’t say. There have been several threads here on BH which covered escrow. I think we should all demand it for these purchases. I’ve shown the calcs before, not crazy expensive.

We have a recirculating hob with grease and carbon filters with a nearby MVHR extract. I’ve set the hob to manual operation of the extractor though rather than it automatically coming on with the hob.

On a related point, even passing meter tails through separate holes in a steel cabinet can cause issues. If you have to do that, put a hacksaw cut between the 2 holes.

Recirculating cooker hood with carbon filters and MVHR extract vent nearby but not directly coupled. Boost the MVHR rate while cooking if you want to.

It's possible in the UK too, but you need to locate the machine outside the electrical safety zones, which often isn't easy in a small UK bathroom. Europe now follow a similar system too though. Though, at least in the case of France, it's mandatory to put electrical sockets in a bathroom >3m²; in the UK it isn't.

Hmmm, I'm still not sure why the discussion is still going down the route of dumping heat to the central heating system and boiler short cycling as a result of this. The intermittent behaviour being shown at the boiler is similar to the symptoms of a blocked dhw plate heat exchanger. The boiler shouldn't be programmed to use the CH to dump excess heat when calling for DHW heating as that's the best place to dump the excess heat. Another similar process is when testing some makes and models of combis in service mode maximum output. Whilst the diverter valve switches to CH for this test, you also need to run the hot water taps to reduce instances of cycling during those tests as that provides additional cooling. The fact that WB are trying to blame a CH system design error on a system that is working to within the operating parameter of the MIs is just total nonsense. If that were really the case then said knowledgeable heating engineer should be able to reproduce and demonstrate the issue to the customer. The WB engineer has kind of already admitted the problem. Now, redesigning, the heating system to be able to handle some excess heat on the occasion it's required may be a way to remedy the boiler design problem, but I would not be confident this would really be the solution simply because the error appears to happen on switching over to DHW, so any excess heat within the hex is an internal boiler issue and wouldn't have a pathway to CH under these circumstances anyway. If the problem was indeed caused by the CH side, we wouldn't be seeing it occur on such an occassional basis given the system is running at max temps anyway. Remember the symptom is no hot water provision at all. So the solution I think is for the OP to go back to WB to fix the problem properly, or sort a replacement because it's simply not fit for purpose. If the boiler has been supplied and fitted by the heating company, there is a fair claim to them to get the problem sorted out rather than the OP. They will probably be better placed to talk to their rep and technical support to resolve the problem. Personally I'd be asking for a different make of boiler built by a manufacturer that approaches boiler control and modulation more sensibly.

I’ve found a solution: I will buy a rifle and some bullets. Lots of bullets. I will buy some <s>bait</s> chickens. (The law allows shooting of foxes to protect livestock, so long as I notify the police within 48 hours as per the Animals Act 1971.)

Jeez @Ferdinand sorry to hear of all your problems. You are very good value on here, so don't you be planning on going anywhere soon, ya hear.

Did you glow when it was cold.

To make sure the roof leaks in future I imagine. 😮‍💨