JohnMo

Hello and welcome. Always a bit suspicious when they we don't need heating and the house is huge. So from the link the heat load is 11 W/m2, the floor area is 550m2, so on a cold design day that's 6kW. Where is that heat coming from, a couple of hours of sun in mid winter may heat a couple of rooms, but a few overcast days it's going to get cool, so I doubt the fire will be cosmetic for long. Small house 100m2, that heat demand is 1.1kW, small panel heater would do it on the coldest days. A2A heat pump, for heating and cooling? Cheapish to install, cheap to run. UFH, or fan coil units, small heat pump and UVC for hot water. Needn't be that expensive.

The other thing could a bird have nested in the flue, the nest dropped down and then caused a flue fire.

Couple of things to think about. The flue is a low pressure region, the natural way for thing to occur is not for the smoke to leak out, but room air to leak in to the flue. Has you MVHR been commissioned yet? Could you be extracting more air than you are supplying causing your room to be depressurised. On the same theme, combustion air coming from the room in a relatively air tight house, will also depressurise the room, causing smoke to leak in to the room. Two things to check, does your stoves primary and secondary air come from outside air supply (assuming you have one installed). Not all stoves do, some will take air from the room also. Is your outside air duct correctly installed and not blocked?

Our french doors also open outwards. Front door inwards.

The practicality really depends on your rooms heat loss do you know this?

Our boiler to ensuite is around 18m with a combi, a little waiting for the hot to arrive, but by the time you have you clothes off, towel where you want it etc, the hot water is there. Not much of an issue. Hot water cylinder would be quicker though. Would not bother with an electric shower. ASHP, can do cooling if you need it, gas boiler cannot. Heat pump economics £2+3k will get an ASHP, if you shop around. UFH is same for gas boiler or ASHP. The other parts with radiators, good chance they will need to increase in size, if micro-bore, this will need to be replaced, so this is a cost adder, a cylinder is required for DHW, with a heat pump coil. You can get a grant, but there is a good chance you can do it way cheaper without it, if your hands on. Energy wise, a well set up system will have CoP of 3 to 4, (1 unit of electric in 3 to 4 units of heat out). A gas boiler will have a CoP of 0.8, 1 unit of gas in 0.8 units out. You just need to look at the cost of gas/ electric. There are plenty of poorly implemented heat pumps. Insulation is your friend, so is airtightness and good ventilation with heat recovery.

Mine came with same oversized steels. I wanted more insulation in the ceiling than the depth of the posi joist/rafter, so counter battened out with 2x 50x50mm battens. That way I had about 70mm of insulation under the steel to reduce any cold bridge.

I've been fiddling with my system, was on straight WC with a buffer in the system, seemed to work great at very low demands, but as demand went up the boiler started using a way higher rate of gas than it should. So went for a thermostat on the buffer cylinder and used a relay to control the logic of when the boiler fires up. So if the UFH has a heat demand, it sends 230v through the buffer thermostat. If the thermostat is also calling for heat, the relay closes and gives a demand signal to the boiler. The boiler only fires when both the cylinder thermostat and the UFH require heat, if only one requires heat the boiler does not fire up. Set the buffer to 30 degrees and the thermostat has a hysteresis set to 2. Have found that the buffer temp overshoots by a couple degrees, so the hysteresis is closer to 4 in reality. Also I have installed a heat meter on the UFH, so this records kWh consumed, but what is really good, shows in real time the kW consumed by the floor, changing every second. Slight changes in flow temp, show a change in kW being put in the floor. You can make changes to set the ideal flow temp, based on heat loss calcs for the average monthly temp. UFH heating is controlled by a simple thermostat, with a hysteresis of 0.25, but would be better if it was 0.1.

We had an old house and when we converted, our doors needed to be FD30, building control said and approved a incemesant paint and smoke seals around the door/door frame and self closure mechanism. The paint had to be applied by certified person, they would not accept me doing it.

Very much the illusion, hense the tidying, when anyone comes to visit, family or otherwise.

Do you have a wife? I'm in the same boat @jack is sailing in.

If you search on here someone tested cooling on a radiator, it was unsuccessful, as it cooled the bottom few mm only

This isn't where I found the advise to install the extracts above the showers, but says the same thing. And also from Scottish building regs, support guidance for ventilation Sect 8.8, d, states the extract should be above shower head or bath. 2030716736_Buildingstandardsdomesticventilationguidance2CNovember2017.pdf

That looks an expensive night or possibly two nights of heat, didn't realise that stuff was so expensive.

You want the flow resistance to be as low as possible, that way the fan can run at its lowest speed. Sorry can't help myself, some comments on your planned layout. You seem to have supply and extracts in the same room. Your study and lounge, should just have a supply only, not extracts. You don't require supply or extract in cupboards, as they are not habitable spaces. You really don't need the supply in the hall either. The kitchen should really only have a extract. I would have the pantry as extract not supply. Bathroom extracts ideally need to over the source of steam, ie shower or bath. In the bedroom or any room, you want the supply air to sweep across the room, so it needs to as far from the extract as possible, in the centre of the room is not ideal.

Not sure it matters too much where you locate the boiler, as long as the flue is installed correctly. If it's legal or not? But looks a bodge, it's not even straight.

Simple 2 zone controller, one zone heating the other hot water and a thermostat, in its simplest form. £100 or so plus fitting. Then other smart stuff, for more money. Loads of options https://www.screwfix.com/c/heating-plumbing/central-heating-controls/cat831042 Really depends on what you need to control and how.

Just had a quick look at the inverter and noticed its G98 approved, which would suggest that once the grid connection is removed, so is the functionality of the inverter. So its/could be an expensive paperweight in a power cut. Looking at the cost of circa 4-5k with battery, you need to get it right. Hope I'm wrong - but please double, triple check you are getting what you want/need from this, or one p*ssed off wife may be the outcome.

You should also have a switch similar to a generator/mains switch. So when mains power is off, and battery is on you cannot electrocute anyone working on the mains cables down the street.

Dt7 is for a flow temperature over 30 degs, then dt4 below that. Would make the job of balancing easy.

Grundfos Unilift submersible pump? Grundfos seem to make a decent pump. Not tried myself.

PV inverters switch off when the mains supply goes off. A generator does not enable the inverter. So unless the battery will run in island mode and not export a live load when the mains is off, you may be being sold a pup. Well worth checking before you hand over the cash.

Certainly not what heat geek states. And their calculations show. But each to their own.

Mine is controlled from a thermostat if there is a requirement to heat the pump runs. The thermostat is set slightly higher than required room temperature, I just located it the hall. With a heat pump, there is a slight disadvantage running rooms with heating off and others on, the internal heat loss between rooms, means a higher flow temp is required for the heated room, so you CoP goes down. It actually becomes as cheap to heat the whole house.

500m2 is a small hotel. Will be full of rooms you never use, bathrooms you never use but have to clean. Hope you are getting a full time cleaner. You should start with a reality check on what you need and what you want - very different. You can quite easily sink £50k into lightning, the same into smart stuff that will be old news by the times it's built.