ProDave

For me, definitely warm roof. But as you are having room in roof (attic trusses) I would go one further, don't use attic trusses but use a cut roof suspended from a ridge beam. That is so much easier to detail air tightness ans means any eaves storage space or service space is inside the insulated and air tight envelope of the building. I still maintain that was our best design choice.

And here is my house, just out of shot in the previous clip.

Why did you get 3 phase? Expecting a big load or have some 3 phase equipment? If you have a single phase inverter, then you want to put as much as you can in the way of other loads on that phase to maximise the chance of self using all that you generate. You only really need a 3 phase inverter if having a large array, 3 times the max power before you need to seek prior approval from your DNO.

As they have UFH downstairs this will have been a major renovation (as well as the extension) adding a lot of insulation. Shame there is no mention of this, or what they have (or have not) done to the walls of the original house. It confirms my belief that an ASHP can only be applied to old properties like this as part of a major upgrade. The major upgrade is the bit being quietly missed out of the "replace your boiler with a heat pump" mantra.

You will need a switch fuse to connect to the caravan, you need one with a metal enclosure to take the gland of the SWA cable. Terminate the SWA at the supply end but at the caravan end, insulate and do not connect the SWA (use a large plastic stuffing gland) and connect the caravan to a TT earth. Get a door on that cubicle, the meter and it's connections are not waterproof and it would not surprise me if BG refuse to connect a meter without a door on the cubicle.

The "plug" next to the tap is not blocking the pipe, it's the thing you would unscrew if you (or the water company) was fitting a water meter. Turn the blue handle 90 degrees from it's present position and water should flow. If not it is not a live connection yet.

The issue with the ac side is volt RISE. Because the inverter is feeding in to the house loads, the voltage at the garage CU will RISE as generation increases. If it gets as high as 253V most inverters will shut off. It all depends what your mains voltage is normally. It will probably be okay but you won't know until you try it.

Which is why most people that bother about making a house air tight, also fit MVHR to give controlled air in and out with heat recovery. In fact if the air test is under a certain number, building control here insist on mvhr.

Re "sticky tape" Where I could, e,g, where the tape was just joining adjacent strips or air tight membrane, I screwed ripped strips of OSB over the taped joint, to mechanically hold it together in the vain hope of preventing the taped joints opening over time. Also I use the Barriar air tight membrane which comes with a tape built in which is supposed to seal overlaps, but because I did not board straight away, I fortunately found the built in tape was useless and started to open up so I gave it a layer of Tescon tape as well. Had I fitted the Barriar using it's own tape and boarded straight away I would not have know the tape was failing until the air tight test and then it would be a bit late. I am surprised the air tight test blew the water out of a shower trap. It is only supposed to pump up to 50Pa which is only a few mm, way lower than even the shallowest shower trap. But that is a well known problem when doing a drain pressure test, I could not get above 75mm before it just blew bubbles though the traps. I did however have to make some temporary wedges to keep the lift out buckets in the 2 shower trays down in place for the drain pressure test.

They will look shite straight, they need to be staggered to look correct.

Don't you normally fit a cooker hood without the glass, and the very last thing you do is lift the glass into place?

We have folding glass screens to keep most of the water in the shower area. They don't need to be full height and don't need to go all the way to and seal to the floor, so we bought off the shelf folding screens intended to go on a bath, and set them about 100mm above the floor. Very little water escapes past them. In our case it was to keep a wooden unit where the towels are stored from getting wet.

The decrement delay of our house is over 13 hours and it provides a very stable internal temperature, it does not heat up or cool down quickly. To some extent, our layout is modelled on the traditional highland "croft house" being quite wide but not very deep front door in the middle, stairs in the middle and rooms either side of the stairs on both floors. It suited the site, wide but not very deep, and was in character with it's surroundings. None of the rooms have massive windows, again in keeping with the style, except for our sun room that is the glass box.

The Highlands is a good choice of location, it is also a very large area so plenty to choose from. And it has the advantage over other parts of the UK that building plots are usually for sale and at sensible prices. As to choosing the layout, that is often led by the plot, i.e. shape, orientation, views, neighbours, etc etc so I would not get too far down the line of designing a house before the plot, but it is certainly worth getting some ideas. Do lots of reading on here, thicken up your skin (you will need it) and get working on your sense of humour.

It is usually a function of the ASHP that it sets the temperature of hot water or heating separately. Unlike a system boiler, they usually only heat one at a time. The detail of exactly how they work varies from one make to another. But mine for instance you set the on and off times of heating and hot water and the water temperature for each. The heat pump decides what to do when both are demanding heat at the same time, in my case I have it set for hot water priority, so when the tank needs some heat, it stops heating the house. In a well insulated house you won't notice that pause in space heating while it heats the hot water tank. Don't over think it. Buy an ASHP and read the manual or if you have specific requirements we can help you choose, i am pretty sure just about every make of heat pump is in use by someone on the forum.

That bit got my eye. WHY would you put the DHW tank so far away? You are going to have stupidly long hot water runs, you will need a hot water circulating system which will have heat losses or it will be unworkable. You want the HW tank in the house as close to the points of use as possible. Distance to HP is not as bad but you will still have losses in the pipes. Is the system actually working properly? Are you thinking of a buffer because someone on the internet says you need one? Or to solve an issue you are having?

The top coat comes pre mixed in tubs. you just give it a mix up and spread it on. On the original application, the quantity was bought based on advised coverage by the manufacturer, and I think we had 1 tub left over, so pretty close to the mark.

Might be worth getting a plumber to pressure test the drains to find problems like that. I wonder how many houses actually get a proper drain pressure test?

The upright timbers forming the dwarf wall are non structural. All the other angled timbers are part of the roof trusses and must not be touched. You could make drawers that slide into each section between the trusses without disturbing those. BUT before you embark upon this, you are talking of incorporating what is presently a cold area, into the room. So you must first move your insulated envelope outwards to ensure the new storage space is now part of the insulated room space.

So it is not working. Call your installer to come and fix it.

Thanks for posting that. The old saying "every day is a school day" is so true, I had not seen that fitting before and it seems to have solved your issue, so duly filed away in memory for future use. (no guarantee I will be able to recall the memory when I need to though)

Turn the thermal mixing valve (on the right below the pump) down, until the thermometer reads the temperature you want. The thermometer is much more accurate than the dial on the mixing valve.

Yes I am becoming resigned to at some point having to re think the cladding, but that is going to be a painful and expensive decision. And just what is different with a thin coat render system applied to a render board? How will that be totally waterproof so rain cannot get in and freeze and blow it? If such a render applied to a render board can be resilient to wind driven rain and freezing, why can't a render applied to wood fibre be so as well? Just one little more to this trying to understand it. My opening post showed how the front wall after being lashed with a lot of wind driven rain followed by freezing temperatures appeared to bulge in a few places suggesting water had got in, frozen and expanded. Well following that it thawed, we had a few mild and dry days and now we are into the second day of sub zero temperatures, it's not been above 0 today, the wall is covered in a nice layer of frost but there are no sign of bulges. So further speculation: Water got in with the wind driven rain and when it froze it expanded. A few mild days has dried it out and there is no longer significant moisture there to expand when frozen. If, and again it is if my speculation is true, then it would tend to favour rain ingress as the problem rather than moisture from within?

Yes that's the whole point, the BBA certificate described this particular render applied directly to wood fibre EWI. I believe this was the only render product approved for this so it's not as though we could try K rend as an alternative.

Well done, always nice to leave the 'van behind.