SteamyTea

Another advantage is one could try out the heating system for a year, just using immersion heaters. Then when you know how your house performs, buy the correct size ASHP. Does require 100 quid of data logging kit, but we should all be doing that anyway.

Hammer and nails, then lots of foam.

Yes, but that is generally a height issue, not a floor area one. All ASHPs should have a buffer fitted.

How many hours a year will you need the full capacity of the HP. Then, how many hours a year will you need more power. Then do the sums, allowing for the drop in CoP and the cost of running extra heating, probably a resistance heater. Don't forget your DHW will take a chunk of time out of the day.

You are the wrong side, china clay tea cups is what can mine.

On a more serous note, you were keeping a spreadsheet of your costs. I know I teased you years ago about the upfront costs before building started, but I am genuinely interested in this barrier to entry for self builder. Especially as the governments pretend to promote self building as a potential cure for the housing crisis. So how is it getting on, any numbers worth looking at? And

A unit of energy is the joule [J]. A watt [W] is a joule per second [J/s or Js-1]. The joule is often changed into the more confusing unit the Wh, or kWh. There are 3,600,000 J in a kWh. This is because k [kilo] is 1000 and there are 3600 s [seconds] in an hour. Just to make it really hard, the joule is a derived SI unit, so is made up from the base units of the kilogram, the metre and time. kg.m2.s-2. This allows it to me used for all forms of energy. J = kg.m2/s2 = N.m = Ps.m3 = W.s = C.V = Ω.A2.s To put it into simpler terms, if a 2 kg mass is moving at 1 m/s, the kinetic energy is 1 J. So about 4.4 lb moving at 2.2 MPH (you can see why we use SI units). 1 J = 0.0009478171 BTU (how horrible is that) To convert joule to Wh, multiply by 0.0002777778 which is just 1/3600 Just for a laugh, and I cannot be bothered to get up out the chair this morning, the letters used in SI units are important. J is used for joule, which is named after the man Joule, only use Joule when referring to the man, or at the beginning of a sentence, the same is true for W, watt, named after Watt, though it should really be named after Trevithick, but we use T for temperature, t for time, which is usually s for seconds. 3600 seconds is an hour, h and k is 1000, K is kelvin, named after Kelvin, and is a temperature scale, with 0 K being the point where motion stops. So if you see KWH that is actually a temperature times a watt times an inductance KelvinWattHenry. Which I think is a totally nonsense unit.

And your trousers up from minor ones. Now this jogger, does she jiggle.

True, unless it has near infinite Henrys.

Not quite, there used to be a way, by using an inductor after the meter, that stopped it recording correctly. Think it messed up the power factor correction. Don't think it works on the newer digital meters. https://www.physicsforums.com/threads/using-inductors-to-reduce-electric-bill.69264/

Yes, we are about to reopen all the fish mines. And all the girls in Ilogan are as horny as Demelza, even allowing for her hip displacement

Is that really right, or is it £0.05, 5p/kWh? https://www.solarpanelprices.co.uk/articles/solar-panels/best-smart-export-guarantee-tariffs/ Will your DNO (that is the people that own the grid) allow you to install 8 kWp without an expensive upgrade?

Seems the closet to Bristol one gets, the more of the ground floor gets covered. If I dig down more than a metre it would be called a tin mine.

Really don't know. There is nothing inherently wrong with using ply, as long as it is the correct sort. Sheets are usually marked up somewhere, so you should be able to find out what it is. https://www.trada.co.uk/publications/info-from-other-organisations/the-builders-guide-to-plywood/

Looks like shuttering ply.

Not my installation. I would just dust off my old RE Science books, the laws of thermodynamics have not changed.

You can pick your own hallucinogenic mushrooms for free. There may be some near a turbines base.

That is why buffer tanks must always be fitted.

I think your Mum is calling you to go outside and get some fresh air.

Really simple enough to make your own. Just some lists and basic functions. If I made you a spreadsheet, it may not show the information you want to display in the format you want.

If it is the correct grade, then yes.

Trouble with that is that there is not a huge knowledge base in the plumbing trade. Many installers are the same people that jumped on the PV installation a decade ago. The big difference between a thermal boiler and a HP is that efficiency is best when the HP is running below its maximum performance. This us why they are oversized. This us not the same as fitting a more powerful combi boiler. They are sized for DHW needs.

It is only recently I have heard any mention of waterbars. Have the regs changed?

Yes. The thing to remember is that you need to stop cold, outside air, blowing across/through the insulation. If air flows across/through insulation, it is the same as having a greater wall area to loose energy through.

That can hide a lot of sins, and holes. You need to make sure that the exterior, OSB I am assuming, is airtight. That is where the losses happen. And, as @ProDave said, at the top and bottom of the walls. Especially true if the roof is a cold one. Between floors, that space between a ceiling and floorboards, where it meets the walls is the tricky bit. I hope that not too much insulation has been fitted before you can check.