Leaderboard

There's the core problem. They couldn't give a stuff, because they aren't paying. Change the heater to one that has half the heating capacity, and hard-wire a timer 0700 to 1800

If they are on a price it does not make much difference if they take lots of breaks. Different on day work and if that is the case I would be concerned. Mention the electric bill and ban the heater to the boss. I don't see the need for a heater just to keep warm. If they are cold they should put more clothes on or work harder.

Buy a timer? Get the electrician to hard wire it in

Aside from any weed membrane you want a damp proof membrane on top of your blocks, then your pallet shed. We anchored a 4x2 wall plate around our slab perimeter then screwed the pallets to that when we did my nephew's pallet shed: His slab had a DPM under it. The wall plate then sat on a DPC abovevthr slab edge. The DPM got folded downward and clad over. You'll then of course need a "floor" atop the DPM or it'll be a bit slippery! Paving slabs are an option or even pallet wood. You could lay some insulation under it too. Ideally any timber wants to be 6" above ground level. He was going to grade/lower the dirt around the shed but hadn't gotten around to it last time I was there.

It matters not two hoots how you use the system. All that matters is if it is capable of exporting more that the 16A per phase. So either redesign so it can't, or apply for G99 before you start.

That will be very expensive to run, and quite crude. If you do an insulated raft and install UFH you can heat the place for pennies, long-term. The cost of running crude IR panels will soon add up. Electric UTH and towel rads in bathrooms is fine, but space heating from IR panels is the last thing I'd ever recommend for any of my clients. Zero sustain, no medium to load-shift, and they heat what they hit, literally, so you'd need multiples of smaller units to spread out heat. The surface temps are also very occupant-unfriendly, and not good for children.

Plenty on here with no heating upstairs as @ProDave says I used electric towel rads in the bathrooms with wet UFH, if doing it again I would consider electric UFH under tiles in bathroom on a timer. Especially if it was not single storey. Not sure why UFH should be expensive. If well insulated 200mm centres should be fine (I'm on 300mm), one thermostat, no actuators, no buffer, run on weather compensation or fixed temp with a 0.1 hysterisis thermostat such as Computherm, job done. Not even convinced you need a mixer, if on a single zone with no rads, could use a pipe stat to protect against over temperature. But even so, a manifold and mixer from Ivar are good quality and change from £450. 1km of pipe £1000 with clips and euro cones.

I have a couple of thoughts, and I hope they come over the right way. First, undertaking any project like this is hard so do cut yourself some slack. It’s a long slog and will be a lot easier with a trusted contractor, but mistakes happen on all sides. It sounds like he’s well intentioned, and that is worth a lot. Second thought is that you can’t be on site every day, so you need him to care about the details as if it were his own house. Getting to good airtightness takes a lot of attention, minimising thermal bridges does not happen by accident and if he’s not checking the subbies and there every day, how can he be confident you will get the results you need? The electric bill seems to be a small symptom of a bigger oversight question?

You need to ‘grow a pair’ I’m afraid. It’s your house after all. I suggest you have at least weekly meetings with them and agree what work is going to be completed that week. There’s also no reason why you can’t point out the electricity bill to them. Whether they’ve done it because they don’t care or just didn’t think is up you to decide. I suspect the latter. My build is a mixture trades and suppliers some of which I have a contract with and some it’s just a list of what they are going to do and how much or how long and a day rate. I don’t have a contract with the groundswork team for example but I do have a fixed price. I’ve been on-site every morning and he walks me through the plan for that day and we make any decisions that need to be made. I then go down at the end of the day and photograph everything that’s been done and note anything to raise the following day.

Fair point. If the oversight isn’t enough things will get missed that are more significant and in a Passive construction that’s not going to be a good thing. Would a “disappointed not angry” approach work? The suggestion to add a timer might work? …or if they really don’t care they will override it somehow?

…to add, I think this is the key point. A good working relationship with someone you trust is worth an awful lot more than some electricity?

I would expect them to be reasonable and not leave the heater on when they are not in the site office. I don’t think there’s anything wrong with pointing out that it’s a lot of money, or possibly that it’s a waste of resources and the environmental cost is poor. Ultimately I think it’s your cost though. I had similar irritations, but I do not begrudge the team having a place to warm up and dry off. The winds and rain in Devon and Cornwall are more than a bit persistent after all. I do get a bit irritated when the doors of the house are wide open and there’s a fan heater blasting out, but usually just swallow it. We were running at around £200 a month for electricity over the winter for contractor use. It will drop substantially when the weather gets warmer, which hopefully is soon. Perhaps just swallow the costs until spring?

There should also be a programme of work showing what works have been completed by a certain date.

How are these workmen employed? Do you employ them directly or have you employed a single contractor? Day rates are a big mistake in my view - there’s no incentive to complete the works. By the way do you have a contracted complete date and are there liquidated damages stated? (Do they still call them this?)

It’s a bit ambiguous - are you responsible for the site or have you handed it over to a main contractor? If you have handed the site over to a main contractor he/she will be responsible for everything on the site and that should include all plant and materials including water and electricity. If however you are managing the site and you are responsible for the site security, materials stored and plant then I would suggest that the bill is yours unless you have a clause in the contract to suggest otherwise. Get those brass balls out and bat that bill right over to the contractor. Being liable to provide a service does not necessarily mean you are liable for the cost. Can you post your contract or post what type it is.

The issue is that they are leaving it on 24/7. Had they only switched it on when they were using the facilities it’d be a third of that cost. Therefore I’d raise it with their boss. You might need to swallow this bill but not 100% of the next one if they just leave it on.

I think you’ll have to swallow it, but let the builder and the trades people know about the bill. You can do this in a way that makes it clear you’d rather not be faced with such a bill, but don’t get angry. Try and get them onside that this is something you’d appreciate their help in trying to improve, and ask them for suggestions how to do that. Then when you’re on site and the heater is not running, be sure to thank them - give them positive reinforcement for the behaviour you want. We provided a caravan as a site office and rest room. We stocked it with tea, coffee, chocolate biscuits but never thought about smoking until the first day when I noticed the builder smoking. We didn’t want the caravan smelling of smoke. At the first opportunity that he was smoking, not in the caravan, I went up to him and said I really appreciated he wasn’t smoking in the caravan. Problem was solved by positive reinforcement. Neither he nor any of the trades have smoked in the van.

Looks like you are on the hook for it, ouch.

You either accept the cost and the same for the next quarter, or speak to the contractor to resolve or agree how or who will foot the bill. What in your contract?

Sadly I think you will have to pay it. You could point out the high cost and buy a cheap diesel heater. Trouble is, once the fuel runs out they fill just plug in the fan heater. Trouble down here is that half the builders are related to each other, and you don't know which half that is, so complaining can cost you.

slide a couple scaff planks under the b and b to sit the acro's on. will be fine.

But even at as low as 15p per unit, the divert to immersion is already close to parity with using gas to heat the water at 11p per unit (plus a bit for calorific conversion inneficiency) But Octopus's new Flux tarrifs are paying up to 36.5 p/kWh for export at peak demand time (9.4 p/kWh, 22 p/kWh, 36.5 p/kWh for the cheap medium and high rates respectively). I know it's horrible but the market is constantly evolving, while self installing locks you out of potential game changers in the future without an MCS cert.

G100 is in addition to G99 so you apply for G99 and if you or your DNO want to limit export you have a G100 application as a supplement to the G99. That's the way that our DNO does things which I beleive is the same across the UK. Certainly for us, G100 means you must use a professional installer who can set up the limitation with factory/engineer passwords to prevent the user altering the settings. It also means your DNO will want to witness the limitation at a cost of several hundred pounds. Not really DIYable with G100. If you want to add AC coupled batteries best speaking to your DNO to see if theyll accept 2 x 3.68kw. If not maybe replace your existing inverter with the hybrid unit so the inverter limits total export from batteties and PV to 3.68kw If your SWA is the right size/spec you can move the the inverter to wherever the batteries are and bring the DC from the PV through the SWA.

Yes, that was the total heating supply for the house. We used to keep the whole house at 23C.

A G98 size PV array with an immersion diverter, there is next to nothing to export, so no feed in tariff adds up to value for money for the extra costs involved with MCS registration. If you have a big array and battery and you can selectively export at peak times and consume electric at off peak, that may be a different story. But not check to install. We have a smart meter, but are 4 miles from town and the smart meter can't find anything to communicate with, so is dumb. We couldn't play if we were MCS registered, as all the schemes require a working smart meter.

https://www.screwfix.com/p/mcalpine-push-fit-drain-blanking-cap-black-110mm/4331v Weird they dont fit for you, push a short length of 110 pipe into the socket then stop that.

https://www.planningportal.co.uk/permission/common-projects/outbuildings/planning-permission "No more than half the area of land around the "original house"* would be covered by additions or other buildings."

The Thermino is a Sunamp, rebranded, eg the same device from the same people. I'm not a fan of the Mixergy tanks, too much complication / faff / additional components / additional heat loss from the PHE / cost of running and replacing the pump and so on. For DHW, simply follow the KISS rule. Adding a second low slung immersion in a well-insulated UVC is all you'll ever need, and you wont ever convince me otherwise. Just an unnecessary over-complicated re-invention of an already time-proven wheel.

The upper edge of a standard UK basin rim is 820-830mm from FFL. A kitchen worktop surface is around 900-915mm off FFL. A counter-top for a 150mm deep sit-on basin "bowl" should be no more than 700mm from FFL afaic?

The guys have taken full advantage of the good weather. Foundations dug, poured, and initial blockwork up. Will be finished tomorrow. Garage foundation will be dug out tomorrow and all the trenches for the ductwork. The cold weather might put the brakes on the slab pour until next week. We have a retaining wall to dig out. We don’t really need to do it as we can grade the ground but it’s not huge and we think it will look better. Plan is to build it in block then clad it to match the house.

I designed and built our last house which was a PH. It was heated with three electric towel rails in the bathrooms and three square meters of electric UFH in the kitchen. A Genvex Combi 185LS supplied DHW heated with a built in EASHP. When required the EASHP also supplied warm air heating through the MVHR ducting.

That's perfectly fine! Since when can't grown-ups have fun.

Been there, done the sums. Passive House with just electric rad heating and 300L direct UVC on immersion here. 100% of DHW on cheap night rate (14c/kWh) and about 40% of space heating on day rate (48c/kWh) For space heating a single A2A unit in central area for the bulk of space heating/cooling with electric resistive in the bathrooms to boost them is cheapest over a lifetime. UFH with a Willis heater using the slab as a storage heater for cheap night rate electricity isn't much more expensive like @TerryE. ASHP on UFH has very low running costs but is offset by the cost of installing first day and care is needed to get good COPs. Direct electric is expensive even with our modest heat demand of about 3MWh/annum. Planning on an a2a soon. ASHP not really worth it for DHW as the COP really drops off above 40deg and you need to have tremendous amounts of storage to heat only on night rate. PV with divert is the cheapest here I reckon. With 2 adults and 2 small kids we use 10kWh per day. A 300l cylinder at 70deg suffices easily for the full day as it stores about 14kWh. If you went for a 500l or left space for a 300l X 2 you would be well covered.

Mixergy cylinders are quite good. Give them a call and speak to them and they will explain them in detail. Having the ability to heat the cylinder at cheap electric times and also to be able to heat what you need is a great feature. We have come across quite a few people that have them now and everyone we have spoken to seems happy with them. Better than a conventional direct unvented cylinder and cheaper than the Thermino although I don't know much about the Sunamp heat batteries so I can't express much of an opinion on them.

Not entirely true, even heating a low immersion the heat will settle after a soon period at the top of the cylinder. Just get a custom built uvc specify 2 or 3 immersions, to give lots of flexibility but also include a 3m2 coil just in case you want an ASHP later. Then just use relays or similar so you PV diverter heats top middle and bottom immersion in that order. But why not look at cylinder with an heat pump in it, CoP of 3, better use of solar when it's available. Beaten to it by @ProDave

To balance in favour of the low tech UVC, with direct heating you can have multiple immersion heaters at different levels and heat the top part of the cylinder first then switch to the next heating element down the tank.

Do not mix UFH and radiators, it just complicates things with different warm up times so you really need different controls so radiators and UFH turn on and off at different times, which seems to fry the brains of most "heating engineers" used to all on and off at the same time. If you are really building to close to passive house insulation and air tightness you probably won't need upstairs heating. I followed the well trodden path on here of not really trusting that, so I put electric points for a panel heater in each bedroom. Like most that have done this, those heater points have never been used and we have no heating in the bedrooms, and this is in the east Highlands, probably the coldest place in the UK in winter. I can never understand why some people get quoted high prices for UFH. I did all mine myself and the materials are not expensive, and it is not even difficult, just time consuming. If you want to fit it yourself there will be plenty of help here, and there is no reason wy UFH upstairs should be much different than downstairs, though you might need to make some decisions very early on in the design of the building.

I am in a similar boat, New build SIPS house hopefully starting soon. The quotes for UFH upstairs are even more eye watering than for downstairs. I am content that the need for any heating upsatirs will be minimal at most. In fact the TF company ( Potton homes) believe you dont need any heating upsatirs at all, except perhaps heated towel radiators in the bathrooms ' that'll be plenty' they say. However, i understand building regs say that there must be heating upstiars. So, we are going with radiators in the bedrooms but very small. A token jesture almost.

Yes, but not as much as trying to find a website that gives the correct advice. Seems every site has a different opinion about how to spot a fake. I just buy them, then calibrate them to see if the readings are sensible.

+1 I wired up my own. Cable cost way more than the actual NTC. Encapsulated 10k NTC with short cables are five for £7.50 on Amazon. Google found these but I've never purchased from these companies... Various lengths Inc 10m for £15.. https://www.ebay.co.uk/itm/183331715037?chn=ps&mkevt=1&mkcid=28&var=690639609095 10m for £21.. https://www.justradiators.co.uk/thermosphere-floor-sensor-probe?ps=MjQ5PTE1MzUx&gclid=Cj0KCQiA9YugBhCZARIsAACXxeLok7yVFEa2erOpxJCsXUTmaseUfl25MJ21u-PweOzb6tuTduS6CBAaAmCbEALw_wcB#249=15351&utm_term=&utm_campaign=Shoptimised+|+Incremental+|+Performance+Max&utm_source=adwords&utm_medium=ppc&hsa_acc=5690114029&hsa_cam=19604440538&hsa_grp=&hsa_ad=&hsa_src=x&hsa_tgt=&hsa_kw=&hsa_mt=&hsa_net=adwords&hsa_ver=3

No clue but sounds surprising they won't pull out the old floor first? Bottom line, amtico only works if the floor is sooperdooper flat

NTC sensor + 8m of cable = profit. / in other words, just extend the cable...

It's a minefield for sure. How to spot a fake DS18B20

I bought a remote probe, thought it was a good idea at the time. Found in a box the other day - full of other good ideas at the time. Where I was going to install I removed the thermostat, didn't need it. Do you need them - no, unless you embed as a high temp cut off to protect a delicate floor covering.

Put a wire brush attachment in you drill Get all the yellow stuff off then paint with SBR mixed 3-1 Your good to go

This is what i did and didn't have a screed above the insulation, just UFH and laminate, its not too springy. I did it this way as in future the outbuilding may be used as a garage. in relation to the roof to save floor to ceiling height, have a look at a hybrid roof. This would be a big no no if it was a permanently occupied and in a cold area, due to the risks of interstitial condensation, but as its an outbuilding then it may be possible. We have done it, and will see how it performs. Have a look what Oakwood Garden rooms say on the matter, though there is some debate. https://www.youtube.com/watch?v=EZFcHcxbFbE https://www.youtube.com/watch?v=P_dBayq3_FA

Here's my go at an over-engineered insulated raft, for a Garden Office. As per @Iceverge, ground should be around 150mm below the finished floor level. No separation layer needed for EPS. To do the chamfer detail on the upstand you'd need to make up a hot wire cutter. If not then a thinner upstand (25mm) will do. Upstand can be stuck and screwed to the base layer. You could, almost definitely, do it all in EPS100, rather the the EPS200 I've shown under the ring beam, as you won't be having a heavy roof finish on that 5° pitch.

The norm is to keep any sole plate at least 150mm above the ground to prevent any splashback damage. The OSB will be a structural component of the building too and longterm fairs even worse than timber when exposed to wet. I wouldn't have them that close to the ground. For the roof you could do a 100mm insulated panel at 5⁰ slope. Even with a 150mm floor that would give you 2m head height at the low side. To drop the floor any further I would have a very robust perimeter drain and a blockwork cavity outside the timber.

You may be able to have the isolator switches for the boiler and washing machine in the room on the left and outlets in the shower room. You could even have a hole in the wall and socket in the other room if you don't want to take the plug off the washing machine.

Get a gardener to come in to keep on top of the worst of it.