JohnMo

Not yet. Watching it all tonight when wife goes out

Tradesmen with hammers and nails and manual screwdrivers. Not sure many now would cope with that. Compared to the insulation standards many follow now, the insulation added to walls etc is pretty thin. Build is very quick, many lessons from that build still not implemented. Part way through second episode

Our walls are Durisol, now Ecobrix. Perimeter is 70m and average height 3m, so 210m², back in 2021, it cost us £27k all in all allowing for cost of a labourer and me to build, all concrete infill, concrete pumping lorry (X2 visits). With service cavity a u value of 0.14. So £128 per m² finished. No additional costs for props etc required. Parge coat or membrane inside prior to service battens or wet plaster for airtightness.

In addition to what @jack says, some UFH controllers are configured to manage cooling, automatically or manually. A normal thermostat set to 21 degs, if below 21 it call for the heat source to start, above 21 it tells it to stop. Cooling needs the opposite.

So do you have a buffer or volumiser? If so where are they located in the system with respect the diverter valve (for heating or DHW)? UFH heating pump and mixer? Thermostats?

Yes but you are then spending needless money etc. getting screed done. Just bring concrete up to FFL - done. Make sure UFH don't go under where internal walls are, take all pipes through doorways. Then you won't get any nasty surprises. Architect will take lots of rubbish about heat up times when buried in deep floors, reaction time, which is only relevant when running against a thermostat I suspect.

One - why are they touching your guttering? What were they trying to fix?

Sounds like you need to find the leak as well.

Download the manual if you don't have it. Normally need volt free contacts making or breaking. If you don't have fan coils or UFH, it will not help and it's not suitable for radiators.

Just use Hep2O.

Why? Flexis are a consumables item, expect a failure. So need to be replaceable. Assume you want an airtight house, not sure how you would make the duct sealed?

The Flexi is just there to break any carried over vibration that could be transmitted through solid pipe. Why would you need multiples. Various lengths here https://www.bes.co.uk/heating-ventilation/renewable/air-source/hose-fittings/?gad_campaignid=21010157190&gad_source=1&gbraid=0AAAAAD9gc2nUit89wBNyhSlbWINtellFp&gclid=CjwKCAjw6s7CBhACEiwAuHQcko06ksxFJVc4OnBQtzTzjmFROda-qjnPCdSxWj2tc56-A6t3EU11fBoCwTYQAvD_BwE

Both the raft and slab support the low and slow heating and they can do batch charge or storage heater mode well. Response will be slow due to the number tonnes of concrete. I see zero advantage to adding a thin layer of insulation then adding screed on top. For me the thin screed will allow heat to leach into the concrete below and it would never get back to the house. With a little care a strip foundation can be made thermal bridge free also. It's also easier (certainly where I am) to get a contractor for strip foundations, but you do have to watch over them.

Progress today - photo a bit squint, not the decking. All diagonal braces fitted. Two stringers to hold PV panels, reduced in height by 30mm to match PV panels. Flashing tape installed on top of PV mount stringers. That was all the wood ordered. So additional 6x2 ordered to split the front and rear bays in to half for roof slats and for additional support for PV stringers - square edge 95 x 12mm wood ordered to make slats for roof. Lots of 45 Deg spacers to make tomorrow for roof slats. Lots of wood to use from other projects for that.

How thick is the reinforced concrete and how thick is the proposed screed?

From the looks of the drawing the cylinder has a low loss headers (a small capacity buffer) which takes the flow from boiler and heat pump. So both heat pump, boiler and heating circuits are hydraulically separated. So a good start, but like a buffer you will take an efficiency hit and you have multiple pumps. The "but", I have experimented with my ASHP, using the inbuilt hybrid mode, the way the logic works it's looking for a target flow temperature within a given tiime. If that conditions is not met, the second heat source is activated. This is where you may need to speak to manufacturer. From what I've seen, when you start your generator the ASHP will see power, so will assume it has enough power to do what it does and it will try to start, because everything is fit and healthy, as far as its concerned. It will trip a small generator on overload. If you go outside and manually isolate the outdoor unit, obviously when you start your generator the ASHP cannot start, but the FTC6 unit on the cylinder has some hefty loads as well, it also has a 24v signal from the outdoor unit (which is switched off). So will you have a permissive for anything to start? I have no clue, this where you need input from manufacturer. Are you looking to get a grant for the ASHP, anything seen as hybrid, is excluded from the grant scheme

So back to topic - topic says hybrid, but the reality isn't that, it's a secondary heat source, which is very different. So in a power cut, you need the heat pump off, or it will try to start up. A hybrid system uses the ASHP primary circulation pump. That will not be available. The secondary heat source needs to have full autonomy to heat without ASHP being powered and using it's circulation pump. In hybrid mode, no ASHP power, no heating. So you need hydraulic separation for ASHP and boiler. And either needs to provide heating circulation and DHW heating. It starts to grow arms and legs complexity wise if you are not careful. Or you install a buffer and take an efficiency hit every day. But that doesn't address DHW in a power cut. @newbuild upnorth you to write down step be step what you really need to achieve. What resources you will have available. Then work through how to achieve it. Hybrid running will not provide heating in a power cut with a small generator.

It's on wheels, pull out of shed, use proper extension to plug into house (external socket), flick the change over relay, full house has power. £700 for geny, £50 for changeover switch, lots cheaper than an oil boiler, tank etc. Log stove?

That sounds huge for a rain water soakaway, thought the size was for a treatment plant soakaway. Our roof area is about 300m² This what our drawings show, with the calculation

Is that by the lorry load or by the 1 tonne sack. Direct from quarry is about half the cost of a building merchant.

The datasheet says 26kg each, but they are also 150mm shorter than the datasheet, so suspect near to 25kg each. Have used bifacial so they are black both sides. Will be using a Ecoflow Stream Ultra battery inverter, each 500W panel goes back to the battery and you can hook up 4 panels individually via 4x MPPT in the unit. Comes with a 2kWh battery also. Apart from panels the rest will be open with timber strips angled at 45 degs every 50 to 75mm (yet to be determined), a bit like this

So day 1 working on my own, will finish corner bracing tomorrow and look at PV mounting. Posts are 100mm square. Side rails are 6x2. Rear vertical posts are screwed to existing decking posts which go up to the height of the rear wall. Used 3x 200mm structural screws on each post.

No it doesn't for a new build house, a 7.9kW geny isn't big. It will allow heat pump to start stop and run while the hob is on cooking the tea. Any Watts excess can go into the battery. I would really just install a room sealed log stove for belts and braces secondary heating. No power needed at all and house heating sorted. And have a back up generator, to run heat pump and house if you want.

I've just started mine, 2x 500W panels in the centre and the 45 Deg slat roof either side. Mine is 100mm posts and 6x2 perimeter framing. Are your panels really huge, your structure sounds huge. Zero chances of it being falling over even if your house fell on it.

Or even easier and cheaper a close coupled tee. So on the ASHP pipe, take suction tee to boiler and return to a tee very close to the first. This would give complete hydraulic separation and let you boiler pump run as it needs. But ideally you would match ASHP flow and boiler flow to be pretty close to each other. It would look similar to the attached, but the pump would not be needed. Assuming the oil boiler has one. Question can you get an oil boiler that does weather compensation and will run priority demand hot water? If you can't this may get messy. An oil boiler may demand mixers on the UFH. Or you do a 2 port buffer, they are more efficient than the normal 4 port but the whole control scheme changes. 2 port buffer temp is the only thing that starts and stops the heat source, house temperature. So ASHP or boiler would fire to manage the buffer temperature. You do a simple electrical change over switch or control on outside temperature to switch over or a combination of the two fire power outages. The central heating side just activates the secondary circuit circulation pump. To do this you are better to use a small hysterisis room thermostat in say the hall, run a fixed temperature on heat pump, say 35 degrees and similar on the oil boiler. Then you need to think of DHW heating - ASHP will priority demand so run two flow temps one for heating and one for DHW. Your boiler? You need to start reading mitsubishi manual to see what it shows and understand what it does first. New build well insulated on MVHR heat demand is very low, an oil boiler doesn't modulate well, if at all. So you will need the smallest boiler you can get. Or a huge buffer.