ProDave

What software are you modeling your heat loss with? There is a simple heat loss spread sheet on this forum written by a well respected former member. I used this to predict the heat loss of my new house, and it's prediction of a worst case heat loss of just under 2.5kW turned out the be absolutely spot on. As built air tightness is all down to attention to detail, all build methods can achieve good air tightness if you detail things properly. There is no such thing as a design air tightness. You don't deliberately design to have poor air tightness, except in rare cases where for some strange reason you don't want to fit an mvhr unit so you deliberately make sure your house is full of leaks so building control don't insist on you installing mvhr. In short you are approaching this wrong. Plan to build an air tight house, plan to detail all aspects well to achieve this, and plan to install mvhr.

Another post i will disagree with. Our plan had a large "plant room" but the realities when actually doung the work, was it made no sense. All that is in our "plant room" is the mvhr, a few electrical boxes related to the ASHP, a circulating pump and an expansion vessel. There really is not much indoor stuff for the average ASHP. Consumer unit was far better on the wall in the utility room. And hot water made much more sense in an airing cupboard formed from the corner of the spare bedroom putting the tank central to hot water points of use for quick hot water delivery. I summary our services are distributed each being where makes best sense.

Interesting. We love our balcony, a lovely place to sit on a nice day and look down on the burn and listen to the wildlife. But out balcony is 2 metres deep, I think it was mentioned in another thread, it has to be big enough to use, not just a narrow space barely wide enough to stand on.

So what I am saying is measure the ridge height on the approved drawings and work out from the scale how high it is. Then see how that compares to the non approved drawing you have with dimensions. I am guessing if no ridge height specified in planning they are not that bothered.

Similar to above, I wish I had moved the house about 3 metres to the east. Initially we positioned the house to leave enough land to the side to accommodate an on site drainage field. During building warrant that became impossible and we eventually got permission for discharge to the burn instead. At that point we did not need such a large side garden so I would have loved to move the house over which would have given more parking on the other side, but that would have meant going back and re submitting planning and starting building warrant again which would have been delay and extra cost, so we left it as it was.

Do the drawings have a scale? Yes I know everyone says do not measure from a drawing but it might be the only way.

It is often a complete unknown what you will find when you dig a hole, until you start digging. We came across a multicore probably telecoms cable, but nobody's phone stopped working so it remains a mystery what it was. Was your pipe "live" i.e. did your hole start to fill up with probably smelly water?

For no nonsense simplicity you can't beat these available almost everywhere for about £20. Ugly as an ugly thing but basic 3 power levels and a thermostat. I have several used for heating the static caravan when we were in it and not used since. * Almost everything else seems to have over complicated electronic controls to comply with LOT20 an EU directive that for some strange reason we seem to think we still have to abide by (but lets not discuss that) * not entirely true. One is still in use controlled by my PV diverter to turn the heater on (set to it's lowest 700W power) on the rare occasions when surplus PV exceeds the 2.8kW of the immersion heater.

I love the parallel universe they live in. Our twin wall duct through the bedroom above gets barely warm to the touch with the stove going full tilt. You could sit a box of matches on it and they would not ignite (please don't try that). The need to keep anything flammable more than 50mm from the twin wall duct is exceedingly cautions.

Is that a new requirement? My twin wall is visible passing through the bedroom above and BC who signed it off were happy with that.

Did the same person dot and dab the PB AND then skim it, or are 2 people involved?

You can get door hinges that do that, called parliament hinges They are basically a standard hinge, but longer, so the pivot point is past the door frame so it can hinge round. you need to get a metal worker to fabricate a heavier version of that for your pedestrian gate so the actual hinge point is beyond the corner of the pillar to allow it to open all the way round. As you have a slope on the drive, if you also incorporated the principle of a rising butt hinge, that would help as well.

The exact wording is crucial. Why can't your solicitor advice how much might be due and what circumstances would trigger it?

All hard wired. There are a lot of different control signals in and out of the outside unit so I ran a 10 core cable in addition to power to connect these and leave some spares.

The thermostat input is I think a 240V switched contact. My older one really is simple, heat demand or not demand that is it. It does in theory have weather compensation. I tried that once with the result it switched to cooling mode. Clearly I had something wrong but couldn't figure out what so I abandoned that idea and have not tried again. What mine does and how seems a long way from what and how the newer ones operate.

Is this space heating or hot water?

If you are talking of burying in in the ground then NO

That is vastly different to a "normal" PV diverter. Your example appears to be turning on the immersion with a relay and leaving it on for a time and re evaluating. A "normal" PV diverter measures PV generation and house consumption (in my case every half second) and adjusts the power being sent to the immersion by burst firing the immersion using a solid state relay. I guess in your case you are using the immersion as a "excess power dump load" so it only needs to be a coarse on or off, with the battery controller soaking up the rest and doing the detailed work.

I previously built a big side extension onto a pebbledashed 1930's house. The pebbledashed side wall became an internal wall in the extension and the plasterer just plastered over it first with bonding then a finish coat. It all worked fine.

That is the controller I have. I very early on worked out you had to get into the mindset of whoever programmed it and there are many things I don't understand about it. I regard it as somewhere to set up the parameters and somewhere to check on it's status. I don't use it for control. Instead mine is set up to use a "room thermostat" to control the heating. That is a jumper option on the control board. Then I have a conventional boiler time clock and room thermostats for the UFH that between them generate the "room thermostat" signal for the heat pump. I chose this method because everybody understands a boiler time clock. It gives you the normal timed options, 1 hour or 2 hour boost, program advance etc.

That reminds me of when I just started work. You could never find an oscilloscope in the winter as they had all been borrowed and were sitting on the floor somewhere to keep someones office warm (Tek 500 series valve scope's)

If you mean products like Multipanel, I and many others have used them and entirely happy with them.

I can't be of much help. Clearly newer versions of the LG heat pumps are very different to my old one that started the thread. Mine cannot adjust the flow rate in the software and cannot even read what it actually is, and if the flow rate is not sufficient (simple flow switch) it trips with the CH14 error requiring a power cycle to reset it.

And I don't think it has been mentioned in this thread yet, that with a well insulated air tight house with mvhr, you will not need heating upstairs even up here in the cold north.

I often wonder why "true hifi" amps get so hot (and waste so much power) You will probably cringe when I describe my "poor mans" surround sound system. It's a Sony DVD player with built in surround sound. The DVD player never gets used, I don't even know if it still works but it takes Audio in from the tv and decodes the surround sound and drives the 5.1 speakers while running as cool as a cool thing thus not wasting much power. We actually have 2 such systems, the one in the other room is Panasonic, that too runs very cool. Both seem to produce good sound.