ProDave

At the dark end of the year, having more panels will let you eek out more from the limited daylight. In summer it will get to full output earlier and maintain full output later. The inverter will slice the top off the output graph. the only reason for doing that is if the DNO refuse a higher power connection or say there will be a big upgrade charge to allow it.

My 4kW with a LOT of shading generates way more than that, so you must have done something wrong for 7kW

Do that "only one radiator turned on" test and the answers might start revealing themselves.

Battery storage may be worth it. Anything over 4kW PV and you will struggle to self use all of it in the summer even dumping surplus into water heating. And remember there is no FIT so at best if you jump through all the hoops you might get 5p perkWh that you export. So in my book anything above 4kW needs costing to see if the extra you can self use is worth it or if some battery storage will be worth it. We self use virtually all we generate but that is largely by using the big appliances in the daytime and about 1/3 of the generation ends up in the immersion heater. Even of you are out is is worth putting them on timers to run close to mid day. And don't forget for more than 4kW you need permission form the DNO so get that permission before you place an order.

Ha ha, cunningly made to look a bit like a chain brake, but not have any function. I agree with @PeterW description of an amputation saw. I suppose it is a silly question to ask where you put the chain oil?

At keast the one that @Onoff hs ordered has something looking just a little bit like a chain brake.

Yes you would need to see his plot to work out what would work. I was just saying why it would not have worked for me,.

A heat pump will never get down to the cost of mains gas but in ideal conditions it will get close. By hoping they will you are missing the point. I bet a replacement gas boiler would still result in what I would consider expensive heating, even if it was lower than the present cost of the heat pump. For most of us a heat pump made sense for a low energy well insulated house, where mains gas is not available, and a heat pump gives probably the cheapest heating available for this particular house. And there is the small matter of greenhouse gasses that should be less with a heat pump and improving all the time as more f the grid electricity comes from renewables.

It would not have worked for me. It would have resulted in the floor level of the house a metre below the road. I would have had to dig a trench to get down into the house or have a half level entrance. And then there was a garage you wanted level with the road, that would have had to had a staircase up to get to it. and then there was the burn and wanting to be well above it from a flooding risk. FAR easier to have the front of the huse at the higher level and the back corner over 1 metre above ground with steps down.

Well done. this is what I have often said, that the key to getting it right is attention to detail, something that is not always easy.

The UFH design should be the same regardless of the heat source. That should be based on how much heat the building needs. UFH should be fed with a manifold that incorporates a temperature blending valve so you can set the UFH temperature independent of the temperature of the water delivered from the boiler. That will let you separately set the boiler temperature for maximum efficiency. You might want a buffer tank between the boiler and the UFH.

That is what is know as an insulated slab foundation. Well respected and used by many. But I am not sure it is right for you, you have a sloping site and want to end up with the finished floor half way between the lower and upper level of the existing site. That means by the time you have stripped the top spoil off the lower part of the site you will be building it up a long way in layers of compacted hardcore to support the insulated slab. I discounted this type of foundation for my site for the same reason, and ended up with traditional strip foundations and an insulated suspended timber floor.

My recent experiences, I would NOT trust PayPal's customer protection.

I would avoid. At least one of the cracks has been patched up and cracked again so it is ongoing movement.

You are assuming that it is the PSU generating the heat, not the complicated CPU chip.

That's very neat. It seems to me the REAL fault is the lack of side vents in the original thermostat casing. Not a lot of point in putting slots in the bottom with none anywhere else to let the air flow through. Sometimes I do seriously despair of people that "design" some stuff. I bet someone omitted them because it spoiled the look, sod the performance.

I would add supply air to dining room (2 supply 2 extract downstairs) Bed 1, supply air to bottom left corner (as far from door as possible) en-suite extract above WC Study supply air over to left, further from door. Loft bathroom extract anywhere but directly from shower cubicle.

I think you have good grounds for appeal there if it is rejected. Make it clear to your planners that is the route you will take but first give them an opportunity to suggest just what would make it acceptable to them.

Thst's an "industry standard" backplate. 1 is neutral and 2 is Live

Regards plumbing and certification the only things we have been asked for from BC in Scotland is the gas safe certificate for the supply to the gas hob, and the unvented cylinder sign off. I installed the gas pipe and just got the gas safe engineer to connect and certify, and I installed theUVC and the plumber just tested and certified it. It does help having trades people you work with from time to time and who know you and trust your abilities.

If the existing sockets are in the right place or nearly the right place I don't think you have to worry about replacing the cable. If it's condition was in any doubt the electrician would not have done the CU change. The thing about the loft, was say you want a new circuit right in the opposite corner of the flat to the CU, it would probably be easier going up from the CU, across the loft, then down the wall to the new circuit. Loft wiring can be left until you convert that. Assuming the CU is in a cupboard that goes all the way up to the ceiling, it really is easy to add new circuits up into the loft at any time.

How have you sealed between the warm house and the cold roof? how have you sealed the loft hatch? I am a huge fan, you could say a convert, to the concept of a warm roof where this problem goes away completely.

This non heating power usage. The lowest I have ever seen is 40kWh per week or 5.7kWh per day. That is when we have been away on holiday with everything turned off, not just left on standby. All that was on, was MVHR, treatment plant pump, Fridge / Freezer and a sky box to record some stuff (and that is on a timer so only powered from 4PM until midnight) And the solar PV will have been generating supplying most if not all the daytime usage (it was summer) so without the PV the background usage would be even higher. How anyone gets to 2kWh in a day living in a house beats me, I suspect (I will measure it one day) a huge amount of that is the FF. I have made some progress in getting our usage down, the total we use now including heating and DHW is about the same as we used to use in the old house where heating and DHW was done with oil.

Flats are especially awkward as you can't just go taking up floorboards without thought and you can't nip up into the loft (unless you happen to be a top floor flat but you don't always even then have access to the loft) So I would be advising work with what you have, replace all switches and sockets for new, and add new sockets to the original circuits where you need them. The fact someone thought it good enough to fit a new CU and certify it should be adequate demonstration that the existing wiring s still in good condition. If you are removing the panel heaters, a handy tip is the cable feeding them can be re purposed as a radial double socket, so that might help with getting extra sockets where you want them, and usually anywhere you have single sockets should be able to be changed for double.