JohnMo

We have electric only 400W towel rails in all bathrooms in addition to UFH. Great for drying out towels when heating is off.

Floor 0.09 Walls 0.14 Roof 0.13. Glazing 0.6 to 1. Rooms at 19 to 20, bedrooms at 17 to 18. Our house is approx 3 to 4 degs cooler than the last one (single glazed 1830s house) and more comfortable, there are no drafts, triple glazing doesn't suck the heat from your body like single glazing did, the warm floor is always radiating heat at you. So room air temp can be misleading.

Forgot to mention, with free loopcad I couldn't get the insulation down far enough so the heat losses are slightly higher on the drawing are slightly higher than reality. I also operate on a 4 deg delta T so flow temps are lower and floor temps are more even.

Longest reach loop would be master bedroom, but there will not be that much pipe in the floor, you are allowed about 100m run, so that should be ok. Dressing room and ensuite do as another loop, both want to be warmer than the bedroom. So you can increase compared to master bedroom to more heat out of the floor at same flow temp and or run at closer spacing for UFH pipes. Kitchen living will have possibly 3 loops, then possibly another 4 loops for the other side of the house. So a single 9 or 10 loop manifold. The rest of the house will just borrow the heat from the heated areas as it's fairly open. Here is my UFH plan. Only change I made, was to meander the kitchen loop around the hall a little near the doorway into the house. My bathroom and kitchen are on the same loop. Works fine. The store is actually an office now, it is fine without UFH as the door stays open and it gets its heat from the hall, which itself is not directly heated. Things I would change are Closer spacing on ensuite and dressing room loops, say 200mm instead of 300mm.

Our house is a little smaller than your a similar W/m2. Your floor buildup makes a big difference to how your floor performs, ours has a 100mm concrete screed and 300mm pipe centres, we have under 600m of pipe in nearly 200m2 area and a thermostat in each room was just a waste of money, as the reaction time is around 12 to 14 hrs. Thermostat are still on the wall, but have no actuators installed now. We now just use a single thermostat in the hall and have balanced flows to get the room temps we need. Well insulated houses are very different from the normal housing. Flow temps for UFH are very low, ours at -9 was 35 degrees and at around 8-10 degrees is 25. Floor surface temp is circa 21 to 22, so if you get solar gain, the floor no longer gives out heat as the room becomes warmer than the floor. Your utility and halls does not need any loops, they will all get heated by the loops passing through them, just spread the pipes out. I would do a single manifold, download a copy of loopcad, and use it to design a balanced system. Go to a company they will get you to install several miles of pipe and about 10 to 12 zones. Which is a real waste of time and money in my opinion. If you are doing zones do them by function, so bedrooms as one zone and living day space as another.

Yes, the fatter the wood the more effort, especially if there is a bit of warpage. Taking the blocks apart a day after is not the easiest. They are all taper joints. We had 60mph winds the other night, without the storm bolts/studs in place. No issues. Our storm braces are 2.5m long studs, going between top and bottom blocks one at each corner.

Our window fixing details were by our structural engineer, and as such part of our structural design certificate - but we are on a windy exposed site with larger than a normal house windows. Window installer details were slightly different, but they went back to our structural engineer to get their details approved prior to starting work.

Did you watch them being installed, if so did the seal the gaps around the window frame and wall with anything. If they didn't you may have a big thermal bridge, basically cold outside air one side and warm inside air the other side of the silicone. If you don't have MVHR you need trickle vents. Did the ones removed have them?

Walls are woodcrete ICF, so don't burn easily. Everything else effectively self insured. Someone stole a wheel barrow, that was all, so I was lucky.

Basically the opening is way bigger that the window frame. The window and doors have flange pieces either side and floats in the opening. Nothing is attached to the logs. Not the best for airtightness but... You can't have everything.

"COMPUTHERM Q7RF." Available from Amazon for about £50

Load of tosh from the builder, you just balance the flows so the rooms don't overheat. Your idea sounds good. If you have a thick screed, the response time is super slow anyway. Then the thermostat is useless, unless you specify 0.1 hysterisis ones.

I had none, told all trades to take their tools home at night. All companies should have have their own liability insurance etc.

I think I would simplify the insulation shape, so you eliminate the void below the gutter. It's just going to fill with debris, however hard you try to stop it. The small triangle make more square so it sits just under the gutter, the piece under that also becomes more simple. Where your membrane mets the composite roof panel, you need something with a long life and remains sticky otherwise you will end up with is leaks. How about butyl tape? But better just eliminate the membrane idea and do the whole lot in butyl flashing. Or do it properly with lead, so it will last a life time.

No make sure every pipe is insulated ideally with at least 25mm thick insulation. I would also look to box the lot in an insulated box, so any heat leaking out of the cylinder and or piping is contained and forms a warm space for it to live in. Then who cars about the the rest of the room space.

If you install a screen, do angled (say 45 deg) vertical slats to turn the flow down the passageway, or horizontally to throw the air upwards.

I have two units a big and small one, the big one was £320 and the small £250. Both from eBay, retail price circa £4k for both from Titon.

Day 2 progress. Stripped walls down to board level 3 (removing about 7 layers) as one of the logs was twisted and caused a big run off at one corner. Built the walls back up and now at roof level. Used the twisted logs at the higher levels, bit of a faff but all good.

In Scotland it actually says "Centralised, balanced supply and extract with / without heat recovery recovery" So MVHR is not mandated, as such, but sure there is much on the market that could provide centralised and balanced other than MVHR.

Just had a look at building regs in Scotland and to have passive stack ventilation your house has to leak more than 5m3/m2. So not really airtight by any stretch of the imagination. Believe you would also need trickle vents in windows or walls as well. On the plus side the room outlets have to be moisture triggered, so it only vents when needed.

Other than what has already been said above. You need to actually go though the plan, line by line and make sure you know the cost of what has been specified. If there is a make and model on the drawing, make sure you are happy paying that cost. The builder will assume you are and will not deviate to save cost etc. UFH needs lots of insulation or you will pay to heat the ground. £17k for ASHP and cylinder is taking you for a fool. If you stay with gas go X plan, so UFH can fire the boiler at a lower temp than cylinder heating. Specify a heat pump cylinder sized (with 3m2+ coil) for a heat pump with storage temp below 50 deg. Boiler efficiency will be over 100%. Get another quote.

The boards at the base are there for ever. That is the base frame the cabin sits on and will be filled with insulation inside and form the floor. The bits at the front will never be seen as there will be a cantilevered small deck with a step hiding it.

No, your the second to ask that today. It's from gardenhouse24.

They seem to have additional nourishment all through the winter and plenty of neeps. The field is about 200m x 250m could be bigger. They have another bigger field they get rotations in also.

There about 40 sheep in the field next to me (if that helps), but most are lambs so not much use for shearing yet. Farmer has to pay to have them sheared and then also has to pay to get rid of the fleeces.