ProDave

Then "health and safety" has over stepped it's intended function. I await the description of how passing through the intermediate bedroom is a risk to your health and safety.

You have a very different household to me. At times our 300L tank is barely enough. Our showers can run in excess of 10L per minute so you are expecting a woman with long hair to shower, wash, rinse and condition their hair in 8 minutes. You have not met my wife and daughter. Double that time and water consumption and my 300L tank barely does 2 lady showers, certainly not if it has done 1 much shorter man shower first. Tell them to turn it down to a trickle and they don't see why they have to put up with sub standard. And nearly 2 hours to re heat it "sorry dear you have to wait 2 hours if you want a shower as well" lands you in the dog house. Oh and most ASHP's (probably all) stop heating the house when they heat the hot water. Ours likes to only do DHW in half hour chunks. You can fiddle with parameters to make it do DHW for longer before reverting to space heating.

Joke of the year award. While having to pass through one bedroom to get to another is not something I want because the occupants of the intermediate bedroom lack any privacy, it is most certainly NOT a "health and safety issue"

I would not go lower than 5kW otherwise I think the DHW reheat times would be too slow. They are already much slower than a gas or oil boiler.

It is a marketing tool, to try and convince the customer they will save money and encourage them to get a smart meter to enable it. I would love to see the statistics for domestic usage in the pesky early evening peak. We are constantly being told that is when demand is higher. So a lot of households must use a substantial part of their daily usage in that peak time? For us it is really just the oven that bothers me and not something I want to have to time shift. But if we all scrap gas, there are going to be a LOT more electric ovens..........

Assuming the chain is what pulls the door up, using it on the small sprocket the door will lift slower. So being forced to use the large sprocket (because the small one is no longer there) would lift the door further for each rotation, thus to my simple mind the torque on the shaft would be more and therefore forces on the teeth would be more. So I would say the small sprocket is what you want. Will you be around in 25 years to replace it again?

It's that pesky 4pm to 8pm silly high peak that I don't want.

And another advantage of a sloping site can be no much away charges. Just use all the excavated soil to build up the lower part of the site to make it a bit less of a slope.

Hi and welcome @R2021 Sounds a good project. I will open the conversation with what air tightness and insulation levels are you aiming for. As you are having MVHR one assumes good? I am a happy user of Rationel 3G aluminium clad doors and windows.

At the other end of the spectrum, you know when your air tightness is good, when on a windy day you can open ONE door or window and not feel a draught entering or leaving the building through it. Every house I have know before, if you open a door on a very windy day, somewhere in the house an internal door will blow shut or blow open due to the gale blowing through the house.

So it sounds like it was tripping on insufficient water flow. Perhaps there is a filter of some sort that is partly blocked and increasing the pump speed has get the flow back to acceptable limits. This is one area heat pump manufacturers could improve. My unit tripped with a low flow error (at least it had the grace to tell you why it had tripped) when I first installed it. Water flow was measured with a flow switch. Now the stupid bit, the installation manual did not even state what the minimum flow was. It took a call to the manufacturer to find that out. I then had to buy a flow meter to find out how far short I was, and the answer was not a lot. I added a second pump to boost the flow.

I was having a discussion with a joiner friend of mine today, and he is saying one of the merchants is telling him that Multipanel are currently not supplying their normal panels with a marine ply backing but instead only supplying them with an MDF backing. Anyone else able to confirm or deny this rumour?

It was a cheap inhibitor / antifreeze that screweys sold a few years ago, intended for central heating systems and mixed at 25:1 would give frost protection to -10

Take the cover off the ASHP, instruct it to start, then go and listen / observe, can you even hear the compressor starting or trying to start?

If there is only 1 CU and there is enough of a loop on the supply cable it might fit inside the CU.

What really really annoys me about this, is the law (or however you want to describe it) says self builders are entitled to reclaim the VAT on a self build. But then the department tasked with implementing the refund scheme seem to operate in a way designed to see how many people they can exclude from claiming the refund. This has been known to be happening for years. Why has the body that set the "law" not given the refund people a good kick up the aris to make sure they implement the scheme properly without actively trying to deny claimants? the only logical conclusion from the fact they have not, is the people that set the "law" want it to be so that people can be excluded for silly trivial reasons. I think Covid helped us, because it stopped the valuation officer making his monthly snooping visits to our site.

That is a "mat well" for the purpose of allowing a doormat to sit flush with the floor. The reason you have several is it will have been designed for a thick coir door mat, and instead you have several thin ones. My guess is the concrete sub floor you are seeing in the mat well extends under all the floor in the hall. Without knowing any more about the house, age, etc one can only guess if it has any insulation under it. You can certainly improve the detail by sealing under the door threshold properly. Does the engineered floor sit directly (with an underlay) on the concrete or is it raised on battens?

I was going to say you don't want to build that with white render in an exposed location as it won't stay crisp and white and clean for very long. This photo demonstrates that and I don't think this one is in an exposed location.

Jeremy created the spreadsheet for modelling his own build and then shared it with the forum. Quite a lot of people have used it since. I built my house as well as I could, but only got an official air test right at the end. I was disappointed with the result of 1.4 yet the tester was excited as it was the best he has ever tested. You might think 1.4 would make my heat loss high? Well in practice the heat i put into the house closely matches the results from the spreadsheet. You will only get the "leakage" air loss when it is blowing a gale, and in any event the air is likely to take the easy route, through the fan assisted mvhr unit and that is certainly how it appears to be. If you built the house with just trickle vents or other leaks, you can never say for certain what the air change rate is as it will depend a lot on where the leaks are, and how strong and even which way the wind is blowing. The lesson is do the best you can for air tightness. Just one of many aspects to detail properly.

I found Jeremy's spreadsheet very accurate, far more so that the SAP calculations (with the same input figures) arrived at. I thought the idea was just play with the air change rate. A totally sealed house without mvhr would be 0. Then add the air change rate of the MVHR to see how much is lost through that. Any further refinement beyond that is unlikely to tell you much. At the end of the day, you build it as well and as air tight as you can and if you meet the figures given by the estimate then you can be pretty sure you have not made any mistakes. But all very interesting from an academic point of view.

To just do trial pits is a very cost inefficient job. You need to get a digger to site, so that is on and off delivery charges, driver hire for probably half a day all coordinated with when the builder or structural engineer is able to visit. Mine cost nothing as I had already bought myself a small digger, so on the appointed day, the structural engineer arrived, i dug holes where he said as deep as he said, pausing for him to peer down them and look at the spoil coming out. Then I filled them in again. If you are faced with a £6K estimate, that would pay for a cheap old digger to do it yourself? then you have it for the duration of the build, then sell it. It will probably save you money when you get the Archealogical survey done.

What was your spec for the house? What was the EPC rating? and air tightnes of you had a test done? What communication happened between you, the builder and the electrician? Who specified the lights? Most of us on here, if asked first would have told you not to fit recessed spotlights in that roof structure, it is virtually impossible to make them airtight, especially if you want swivel ones. We would either have advised changing the roof structure, or fitting some other form of lighting?

Four horses and a reindeer Too much laughing water.

Hand them to who? Not the new owners to move in I hope? Agrees all trades are busy in the run up to Christmas, then in January you think your phone is broken because it never rings

We have some big caverns up here, man made dug out of sold rock, previously used for oil storage https://en.wikipedia.org/wiki/Inchindown_oil_tanks