MikeSharp01

That does not look good - relying on a couple of screws and not the top string and / or a hanger feels very wrong, send these images to the joist manufacturers and see if they are cool with it - I doubt they will be although the runs are relatively short and the steel frame is doing the vast majority of the work assuming the roof load is appropriately transferred to it and I am not sure it is here. If things are as wrong as I suspect you will need to work up a strategy to tackle your contractors on Monday. Others with much more experience will be along to help with that I suspect.

Great word - assume it means busted?

+1 doing this here.

Ah yes but will you also be showering and cooking at the same time? Anyway as you say just dump the electric showers and all will be well. Back to sizing the ASHP - you have all the data you need so looks to me like you need a 5kW unit. The one we are looking at is 6kW the modulates down to 1.8kW - according to the blurb, we have a heating load of of 1.2kW at -1oC (We are in Kent so not the -10oC of @JohnMo and @ProDave )

You cannot operate that much unless you have very large plant - in which case you should be on 3ph, on your own, assuming 1kW extraction plant and perhaps 1.2kW motor on the machine you are running your need is actually only 2.2kW so that's an example of the diversity that @ProDave was talking about. Only the background load of the place will run 24/7 so needs slicing off the top everything else will only run occasionally and rarely together. There must be a standard way of working out the diversity, somebody on here must have discussed it, or at least estimating it, e.g assume 75% of the 'equipment' running worst case doe that get you under the 100A?

And there was me trying to simplify it down to 2 choices. One thing Buildhub is very good at is offering a range of tried and tested schemes none of which ae quite perfect even for the people who advocate them. The challenge is to make your choice from that lot or synthesise your own solution as a combination of several. Perhaps what we need to do on BH is develop a definitive guide to this fundamental decision that has longevity at the start of any build. Otherwise you start off in one direction and end up swithering all over the place. We are past first fix now and have just decided - yesterday to install a fan coil coil unit in each of the bedrooms - the location of which will be sub optimal because we didn't factor it in at the start. We did think of cooling and designed in a passive stack system which has proved very useful over the past few weeks but still has the other half worried the bedrooms will be too warm. Same has gone for our change from gas boiler to ASHP but that, at least, was a choice we made way back but not until after we had moved the gas meter and installed the gas pipe in the slab!

Yes - would agree cycling is a better term.

Looks like the JS Harris spreadsheet to me.

Calculation is a good plan but won't account for absolute capabilities of the ASHP itself so your outcome will inevitably be a compromise between the absolute theoretical demand worst case (which you already have for heating @ 2kW) the rate at which you want to reheat your domestic hot water (DHW) and any additional strategies you may want to put in place e.g. direct electric heating of the DHW to support fast re-heat and your overall control strategy - see below. You will need to decide what operational strategy you are going for as this also impacts the final system - will you just run the system as a single open loop with weather compensation or have a number of zones all controlled separately by their own thermostats or some other combination. In the end you will arrive at a simple set of high level options all of which will have details that define the physical system and its components: Small ASHP say 3kW able to modulate down to 1.5kW which will run your heating, with some short cycling (ON/OFF) because only on the coldest days does the ASHP match the load perfectly on all others it has more output than you need and a slow heating of DHW, if you want faster then the immersion heater is available. A larger ASHP say 6kW that might modulate down to about 2kW which will run your heating but with more short cycling because it is oversized but your DHW reheat will be much quicker and so direct heating is less likely to be needed. Do not forget that ASHPs have a standby power drain, keeping the crankcase warm etc, that may be factor for you and you may want to factor in cooling as a possibility which will ask more questions of ASHP particularly the smaller ones.

Sorry yes ours is aluclad timber. Yes have a buffer with a locking stop on wide open and are looking at a damper to stop it moving too quickly.

Most of the big 3G companies have them, ours is from Norrsken.

6.8kW peak, Inverter limits export to 6kW as per our UKPN GXX certificate

Just ran our system through the PVGIS system. Previously I just used the PHPP calculator to work out how much we should be getting, as this is the final arbiter of whether or not we get Passive house status. Interesting that the PVGIS finds our total generation should be 7,829.84 kWh while the PHPP package using the same data gives 5,723 kWh. The PVGIS has no settings for shading but even if I remove the shading from the PHPP sheet it only gets to 6,500 kWh. So with shading the PVGIS should be a little lower I think. Interestingly though the reality gives another angle - see below. PVGIS PHPP Actual production this year (Exceptional I know) yet to be established but for export alone we have for the first two full data months: May @ 993.262 kWh June @ 1,052.983 kWh The predictions are not in agreement and actuality seems to favour the PVGIS prediction (May @ 1026 kWh and June @ 1061kWh) if anything but only given we have had an exceptional May / June and these are EXPORT amounts not generation. Both May and June were a fraction out, by hey who is counting, - everyone of course.

Is this your house in Kent, as was, very tidy piece of work although there seems like a lot of isolation valves!

https://alertelectrical.com/beadmaster-square-74-for-single-socket-or-light-switch-bm-square.html?variant=51288796561754&country=GB&currency=GBP&gad_campaignid=208985893

I am a great fan of dungarees when working on the site, to get them to stay on the shoulders I have to cross the shoulder straps behind my back (see image one). Yesterday the latest copy of 'Narrow Gauge Times, I appreciate it's not for everyone and not much to do with self building, dropped into the letter box and so I spent a happy hour thumbing through. I came across this photo of a world war one derailment of a stretcher wagon and the team working away to get it back on the rails and the stretcher case back to blighty. (see image 2 - attributed to the Imperial War museum) One thing I noticed immediately was the way the guy on the ground pushing the wagon back onto the track was wearing dungarees with the shoulder straps crossed and it struck me that the problem of the shoulder straps falling off has not been solved in over 100 years, wonder why? Image 1 Image 2.

Tomorrow I need to install three pattresses - exactly the same so easy to make and fit. I already did the one we have planned for the snug but I think it sensible to install these three for future users, just plaster over the back boxes with those little covers and put an accurate drawing of their locations in the house file. I will run cables to the local power and AV connections and leave them covered up in the back boxes. I know it seems like a lot of work but at least one of these spots will probably get a TV in our time but we are trying no to sully this 10m x 3m wall with anything but Art at the outset - pretentious I know! Anyway deciding to put them is not the problem here. I am wondering, give the future proofing thinking what layout of pattress and service back boxes to use. Only one rule really - The other half of our relationship hates seeing wires so all the services MUST be behind the TV. It comes down, I think to one of two - see below. For the various possible bracket options really. LEFT (Flat to the wall) or RIGHT (floating bracket.) is either of these approximately future proof. I have used a 55" TV but my research tells me the same bracket area could go up to a 70". Any thoughts anyone?

Yes they have extra strong plasterboard on the ceiling below so all will be well - until it isn't

Yes, as I understand the simple export system. The 30 minutes readings however are critical if on the 'agile' tariff as this needs to be absolutely clear how much went in and went out in each of the 30 minute periods as a gap could be much more difficult. As I said the back end tool ( https://www.octopriceuk.app/missingData) as @Rob99 points out above can see our missing data, as I show just below rob99s post, so I assume octopus must use that to do the 30 minute calcs for Agile working out. It would be good if I could get a local reading of the smart meter but I am not sure this is possible although I hear tell of wifi smart meters - anybody know if a local reading is possible?

Yes we did and two things came out if it. Firstly the data was in the Octopus back end all the time as I could see it via the detail tool, it just was not copied across to the main viewing system. Secondly the way billing works on the simple Octopus export, not agile, is that they use the last meter reading of the month and so errors from intermediary readings don't matter a jot BUT if that one reading is wrong then the bill will be wrong! So I have added a line to my logger to record the total exported by the inverter at 10 seconds to midnight on billing day, and every other day actually, so I can check the bill readings.

Wow that is some battery! Not a massively difficult task and you may be entitled to grant for £7.5K to help you get it done. PS I see this is your first post so welcome to THE forum for people like us.

Not us yet we are going through the process - we have prepared all the ground including UFH, manifold, In and Out 28mm pipework, control cabling, power supplies. We are just waiting for the chosen ASHP to get its MCS certificate.

In my day, young man, we worked such things out with a slide rule!

Sounds like fun and welcome to THE forum for people like us.

Where do you get a tariff like that we are on 25.97p import!