Omnibuswoman

We were offered fixed price, but at 10-15% more than the estimate so that he wouldn't lose out in the event of unexpected costs etc. It was a difficult decision, but with our finite resources, the cost of things spiralling, and the fall in the value of the investments that we were cashing in to fund the build, we just couldn't afford to find the extra money. We don't distrust Dan and his intentions - he put a great deal of work into the estimate, and his office manager/finance person is tracking it carefully - we just worry that his guys on site are a bit lazy, and spending too much time wandering around smoking/visiting the workshop. Unfortunately, for complicated reasons that I won't get into, we have had to call an end to the work once the outside is complete. So they only have renderboard, windows and doors, and rendering left to go before the work stops. So the rest of the build will be direct subcontracting, when funds allow, with me on site supervising. This will bring its own set of challenges, mostly with me having to learn enough to be able to effectively oversee/quality control that work. There's also the whole gender thing to contend with - some men not liking having a woman question them or oversee their work - which brings its own set of complications.

I find it quite efficient, and absolutely love driving it. We've the van version so enormous open space in the back for stuff. Around town we only use battery. We get approximately 30 miles on one charge, which costs us about £2.30 when charging on the street via one of our local lamp post sockets (24p per kWh). Plus we get the bonus of being exempt from ULEZ charges. On the motorway it's very efficient for a 2 tonne vehicle - It uses around 2/3 of a tank to get down to our plot, but the tank is quite small and only costs between £40 and £50 to fill it up at current prices. And that is with the back full of crap usually. I definitely would recommend. On the panel issue, I will have another chat with our solar guy as we haven't discussed optimisers. I wasn't anticipating much problem with shading, but will revisit that...

We're not on fixed rates - it is a daily rate. But we have a very detailed quote from Dan which breaks down every task by the estimated cost of labour and materials, and we monitor that against the actual charges that are invoiced. So we are able to see if something has come in over or under the estimate, and then can see whether it was materials cost or labour cost that caused that. It's as close as we will get to a fixed price contract. If labour causes an overspend, then we can have that conversation with Dan about idleness.

I've enjoyed reading the various reactions, and understand the range of views. We've called a meeting with Dan, and his office manager/finance person, for later this week to discuss exactly how the costs incurred on this stage compare to the very detailed quote he gave us - the costs are being tracked against the original quote, which was the 'target price' set out in the contract - so that we can see if labour costs are coming in higher than expected. HWMBO said that if the costs being incurred are in line with the quote, then he doesn't favour kicking off about idling about on site. I agree that after having examined the original quote very thoroughly indeed, line by line, we did feel that it was representative of an acceptable pace of work and therefore if they are on track with that we should accept that there isn't a significant degree of piss taking going on. However, the heater is now off, and staying off. When they returned to site this morning, I heard one of them comment that the workshop was colder inside than the outside temperature. Perhaps that will encourage them to hang out in there less. They are battening the outside of the house at the moment, ready for the renderboard to go up. I wonder if anyone has a view on how long it should take three men to batten the outside of a house that is 230m2? It's a simple rectangle - 11m by 8.7m. They've been at it for 5 whole days now, and I'm still wondering if they should have finished by now... The electricity bill is the subject of a separate email in which we very strongly made the point about how shocking and upsetting it was to see use of electricity at 58kWh per day (for the 70 working days on site that the bill covered), and that this demonstrated a failure to exercise proper stewardship of our resources. We have asked him to pay towards the bill, and will see what he comes back with about that. @Jilly we also made the point that this represented almost 100% of our anticipated annual electricity use for our entire house, AND that given that this is meant to be an environmentally conscious build of a low energy house, it is especially galling to see such shocking energy waste. I suspect he will offer us something, as this is an important project for him. Very much appreciate all of your kind and thoughful replies. Here is a picture of our house, for your enjoyment, with Milo the whippet for scale M

You're right, I need to get a grip and just concentrate on being more effective. To be fair to me, I'm not feeling great today and have just tested positive for covid, so I shall use that to explain/apologise for being so annoyed this morning and will speak to him properly and fairly tomorrow. It's important to keep the two things separate - the irritation about the bill, and my concerns about his lack of site/employee management.

We didn't take any advice on this - we pushed him to give us a contract, so he went online and got this one. I don't think he was trying to pull a fast one on us or anything. I went through it with a fine-toothed comb and was satisfied that it set out the various responsibilities clearly, and had an arbitration/mediation element in case we fell out. If we had wanted a fixed cost project his quote would have been 10-15% higher, so we accepted the target price model. We receive an updated spreadsheet fortnightly showing the breakdown of the latest invoiced costs against the predicted budget/quote. I think what bothers me most is that he is rarely on site, and the builders who are (whilst clearly skilled builders) are disrespectful about him. He evidently has no authority or control over them, and no clear expectations as to what they ought to be achieving in what timescale. When asked, he couldn't articulate what he expected, beyond saying that he trusted them. I suspect that trusting them is his preferred alternative to managing them, which may be beyond his skills. And yet this is what I believe we are paying him for.

@Kelvin We took the path of entrusting this responsibility to Dan, the building company owner/main contractor, and are paying him for that role. Our site is 240 miles from here, and I simply cannot be there, and do my day job, hence going with a main contractor. I now somewhat regret that I have not been holding Dan to account more stringently and more often - although doing so without any real knowledge of what I might reasonably expect is challenging. This is an area where he knows more than I do, and to some degree we have had to take it on trust that he is directing the work properly. I'm still not in a position to go and make myself present on site, but I do think we need to meet with Dan to find out the timescales for the remaining external works (battening, cement boarding, rendering, fitting windows and doors) so that we can at least hold his feet to the fire a bit more. He is excellent at building houses, but rubbish (it seems) at managing his employees.

I would say a qualified yes to that - trusting the team is the issue here. The bill, which is not a small amount given the various constraints on our finances well set out by others considering building in the current climate, is a red flag for me as to whether they can be trusted. As ToughButtercup says, they don't give a crap because they're not footing the bill. I don't behave like that at work, and I don't expect others to either.

@ETC copy of the contract attached. The site is the responsibility of the contractor, but we are responsible for providing water, electricity and wifi. copy of contract in word.docx

They're on a day rate unfortunately, and I profoundly lack confidence in the boss's oversight - the last time we had an issue, after I had spent two days on site and found very little seeming to be happening, I asked Dan about his expectations around work for that particular week. He just didn't have an answer for us - he said that he didn't really know because 'it depends on what happens' and that he 'trusts' the guys to be working hard enough. I think he has no governance over their work, and they don't respect either him or us. I've asked him not to return them to site until we have met to discuss. As Steamy Tea says, it's very risky to be seen to question their work ethic in a place like this. We're the grockles from up country, and I suspect there is some degree of feeling that we deserve, or at least can afford, to pay them to do as little as they wish. We don't want to fall out with Dan - he is knowledgeable about Passive House building and really cares about his work - but he is just not supervising his team, and this is probably just a sort of final straw for me around lack of stewardship of our precious resources.

It just says that we will ensure that there is water and electricity on site for the build.

Having found that Octopus can install a SMETS2 3 phase meter for us, in mid Feb we gave British Gas notice along with a meter reading. Imagine the shock when we received a bill for £1,500 (for electricity use since 3rd November when the work started). The builders have been running an electric heater in the workshop/facilities area pretty much 24/7 since early on in the build. Initially this was to dry their wet work clothes overnight (and as this is Cornwall there was quite some rain in Nov and Dec). However it seems that they have just enjoyed having a cosy little place to sit and have utterly disregarded any thought of the cost to us of this. I am really annoyed and upset at this shocking consumption (just over 4020 kwh in 14 weeks), minus weekends and about three weeks of time off site. I'm not sure what to ask our builder to do to put things right. Should we be asking him to foot a portion of the bill? Or should we just stump up for the bill and let it slide, whilst carrying the resentment? I think for me this fits into a wider concern about the workmen's work ethic - the fact that they appear (on our security cameras) to be in and out of the workshop all of the time (probably because it's so flipping warm and comfortable). I regret not having been present on site more, and that the company owner, Dan, has basically left them to their own devices. I lack confidence as to whether we have achieved value for money from their work, and these feelings are all playing into my anger and unhapiness about the electricity bill. Any advice about what to do would be very welcome...

Thanks Wil. Yes I asked our builder to negotiate the company down a bit, and he then mentioned that his 10% has been included in the quote, which is in our contract. My irritation is that it seems that the original company is charging their full rate plus our builder’s 10%, even though they have an existing relationship with each other, and he is not getting the usual trade discount that would absorb his cut. I’ve also asked him to seek other quotes so we will see if they come back any differently.

Yes the scaffolding is still up as they are doing the roof now. Hopefully I can get this sorted swiftly so that the top layer of scaffolding can come down before long.

@SteamyTea in that case the cost looks quite reasonable. 8kWp for £10,500. Still, I will get some quotes for comparison.

As the roof is under construction, the panels will replace slates, so I’m not too worried about area as there is a cost offset there. My main concern is that the project is priced in the right sort of ballpark, as I know that PV costs have fallen a lot lately and finding information on the web is more challenging than I expected.

My experience with Western Power was that they initially quoted me almost £15k for something that, when challenged, may not have been justified. I spent a lot of time gathering information about local loads on the line as I was convinced they were wanting me to fund a local infrastructure upgrade that was already badly needed. After asking them for detailed figures on this, as permitted under the relevant regulations, they dropped the cost to £950. It’s worth taking a close look at what they are quoting for and it’s necessity for your project.

The interesting question has to be, if vector sum metering means that any electricity exported is offset against any electricity imported, how is a battery economically viable? Are we not just as well allowing anything that we don't use ourselves to go to the grid as an offset against what we have used? Or am I fundamentally misunderstanding how this works, and wronly assuming that any electricity exported in any given 24 hour period is offset against anything imported?? @Dan F @Nickfromwales

Just watched the video - a perfect idiot's guide to how this works. So in effect, it matters not how we set up the house demand across the three phases as long as we have a vector sum meter totting up total in and total out.

Thanks for your replies all. Bit of context: This is a new build, so the panels are going up (integrated into the roof) fairly soon. The array is 8kw spread across an E/W roof - roughly 1/3 on the E and 2/3 on the W. @SimC I had a look at PVGIS, but I couldn't figure out how to change the roof direction from South facing to East or West. Is that the figure in the box labelled Azmuth? I don't know how to express the direction in degrees, so any wisdom you can share on this would be great, thanks! Thanks for the comments about the phases and net metering. The 3 phase supply was installed last year by Western Power - their preferred choice for all new properties apparently. We have a digital meter on the outside of our workshop, adjacent to the house. I have gone back to the supplier of the quote to ask more questions about the inverter and phases - i.e. what his thinking is around this, and have cast the net to some other local suppliers for quotes to see what they propose. We don't yet have a smart meter - in order to get the supply connected we just went with the first company that could give us a reasonably short date for this - British Gas - many others were unable at that time to even commit to a date at all in late 2021. We plan to move our supplier to Octopus or Ovo, although we're a bit concerned that it might take quite some time to get a smart meter installed, judging by others' experiences here. For reasons of budget, we are not going to go with the batteries at this point, but will design the system to take batteries so that we can install them further along the line. The electrician we have chosen to do the electrics in the new house has no experience with solar panels, so we think we will have to find someone with this expertise to help to design the system, then to have our electrician fit it. I'll have a look at the posts that DanF referred to, and will do some more googling. I previously joined a forum for electrical and electronic engineers (in order to be able to negotiate with Western Power over the cost of the connection), so I may pose the question about phases and metering on there to see what pops up. Any knowledge I gain, I will bring back over here. Cheers, Omnibuswoman

I have reached the point of having obtained a quote for our PV system, attached, from a local company via my builder. Happy to hear any feedback on it - I thought it seemed competitive for an 8KW system with REC 365w twinpeak black panels. We won't be going with the batteries at this point for reasons of limited budget, but plan to add those in at a later stage. The total cost without batteries is £10,500. Before I seek further quotes, I really need to better understand how solar systems work for houses, and in particular with a 3-phase supply. I'm not certain that the quote provided is suitable for a 3-phase supply. My knowledge of electrical and electronics is really poor, and I need to have a look at an idiot's guide. Can anybody point me to the most basic of basic explanations of what each bit does, and where it goes in the system? Thanks!

Yes spot on. I tried modelling the shading effect but gave up as it was too tricky. Instead decided we should site the panels on the northern end of the East facing roof, away from the dormer.

Thanks @S2D2 Those are good points. I need to do some more learning about how PV and household demands work in real world scenarios - so far this is very much an academic exercise based on a set of figures for average household use. We may well be below that, although we do plan in the future to get a fully electric car and will use PV to charge that at home. I’m not sure what PVGIS is so I will look that up. Are you able to point me to an idiots guide to domestic solar PV?

@SteamyTea We've decided not to go for a heat pump just now on the grounds of cost v benefit. Whilst it would save us some money, the low level of heating needed, the use of PV for hot water for 2/3 of the year, and the use of WWHR means that it wouldn’t be likely to pay us back the outlay in its lifetime at current prices. We will leave the infrastructure in place so that when/if they drop in cost, and/or electricity prices rise further, we will revisit the idea.

no, I’m not wholly sure. Currently our heating and hot water are from condensing gas boiler. Our electric use is plug-in stuff only plus oven, so the new house being all electric will increase our use as our hot water will be from an immersion heater and our heating will be from low temp rads from same tank.