ProDave

Check the tundish to see if there is any discharge. It sounds like one of the relief valves opening or closing. The megaflow tanks have an internal "bubble" for expansion and there is a procedure to regenerate the expansion bubble which would be my first thing to try.

As above. I would not have even mentioned previous animal waste. I would just have mentioned previous rainwater drainage that has proved satisfactory.

Are you suggesting to lay MOT in the trench, then pour concrete then build the wall? That is not normal. Normal is concrete in the trench blocks straight onto that. It would be cheaper to buy a few more wheelbarrows and get some mates or paid labourers to barrow it round. Preparation of the rout is important to avoid steps or other obstructions.

Oh dear. Why on earth would they cut continuous long beams? As others have said. Halt any more work and any more payments and get BCO and if necessary a SE to look at what has been done. In an ideal world it would all be re done, but now it has been built up on top of those joists the easiest solution is likely to be to get a SE to specify exactly what to do to make the present work safe and stable, and then watch them like a hawk to ensure they do that exactly, even things like using the screws or nails that the SE specifies, not what happens to be in the back of the van. P.S our joists also have more sections of I beam at mid span acting as noggins as well as those in my photograph above the bearing points.

I would be very surprised if the tanks are plastic. Most likely brick or concrete. Lift the lids and see.

This is how ours were done Short sections of I beam came with the kit to go in between the main ibeams where they rested on a supporting wall. They did not fill in the web, but that might be because our beams came made up as 11 metre long beams to span the entire length of the house resting on supporting walls on the way, so no joint between separate ibeams as you have in your case.

I did the same with our airing cupboard for a similar reason, but it was a pair of sliding doors so a sliding door closing up onto a wall with no door frame. It looks fine. If you are not happy with the look, an alternative is make that side of the door liner separate to the rest and retained with just a few screws so you could easily remove that side door liner.

Check the planning history. You might find the existing shed has PP

So basically they have not fitted the door and door liner?

There is something more fundamentally wrong here. That does NOT look like a load bearing wall, there should be a double header. Anyone else care to confirm that or tell me it is okay?

What does your building control inspector say? If (s)he says it is wrong, the builder might stand up and take notice.

What a static caravan brings to the party is a way to get over the permitted development eaves and ridge height limit. They have a different limit of internal ceiling no more than 3M high. And they are exempt from building regs where some large outbuildings might require that. They can also be very cheap in terms of £ per square metre. So there is merit in buying one and improving it.

Ditto for me. Except it was me with my rods that found the water main, not where it was mapped as being, when the Scottish Water subcontractors were about to give up and go home because they could not find it. someone that can do divining (that might even be you, go on try it) could follow the water pipe out of the garage to the well.

It's an optimistic name for the master bedroom.

This site is worthy of a look not necessarily to buy from them, but because they show a lot of different options. https://www.continal.co.uk/systems/suspended-floor We used the pug mix system, very cheap and easy, but make sure the joist are rated for the extra dead load.

You can have a static caravan as a garden outbuilding without planning permission. If you connect it to a drainage system that part will need a building warrant but still not planning permission. Expect to get someone from the council snooping. If you are just using it as a general purpose garden building as for instance storage and a work place, or a summerhouse then you will be fine. What the council wants to check is you are not using it for self contained habitation. That is where you will need planning permission. So if they suspect you are using it for that, they have a right to come and check.

It will be interesting to see how much difference it makes, but it is like permanently having a very large loft hatch left open. It is also disappointing that the surveyor did not mention it might be a good idea to close off that gaping great hole and insulate above it.

I would frame and board over that hatch. Then insulate that new ceiling from the eaves loft access. At the moment warm air from the house can get up that great big hole, meet the cold air in the loft and it is no surprise condensation can drip down the old chimneys. In the short term stuff some rockwool down the old chimneys from above and lay a sheet of it over the top of them. You will find your house warmer and heating bills lower when you do that.

If you can get into the eaves space you should be able to see the top of these old chimneys. Start by insulating the eaves space with normal rockwool type insulation making sure the tops of the old chimneys are covered. for good measure stuff some down from above. Once all nicely insulated replace the plasterboard with foil backed which is more resilient to moisture.

Those look like the remains of 2 chimneys, hence the black, that is years of soot. It looks like the chimney stack above has been taken down and roofed over? (more external pictures might confirm) and the lower internal chimney breast removed.

It all became "worth it" in 2 stages, first when we moved in to the unfinished house (from the static caravan) and then 4 years later when the old house sold. Short version of story, we started in 2013 put our old house on the market in 2014 and it did not sell. 3 years it was on the market with no buyers, several other properties around us were the same, simply no buyers. That was the low point. Shell not even wind and water tight, no money to continue. Plan B was an offer to rent the old house with the intention to buy it later so we moved into the caravan and did that. We than had a slow "build as you earn" and completed nearly 2 years ago, and the old house finally sold to the tenant at the end of last year. Lessons from this be flexible with your build and financing plans. If you can't be flexible, don't even start until you have funds secured to at least get the house habitable. I cannot describe how demoralising it was to have an unsalable house and no funds to continue the build of the new one.

The usual configuration is a desk under the bed so you don't need full standing headroom.

I assume you have very high ceilings? Otherwise a standard 8ft ceiling height and 6ft under the bed, allowing just 6" for a mattress will give you only 18" between the bed and the ceiling. It will be like sleeping in the quarter berth on a boat. Don't try sitting up in bed.

That works out at pretty much £10K per bicycle space created. I sometimes wish I was fortunate enough to get such a contract at such a silly inflated price.

The whole flat felt roof looks very poor. I really dislike totally flat roofs. That looks in poor condition, witness patch repairs and staining where it looks like it puddles. There is an upstand along most of the edge of the gap, and that ends near the sloping roof as if it is designed to allow the water to run off at that specific point into the gap, but with no proper means to deal with that run off. If it were mine, I would re roof that flat bit totally. You have enough of a step between the flat roof and the sloping roof, to put a bit of fall on the "flat" roof so it drains to the right of the picture, and an upstand ALL the way along the edge of the gap to stop water draining down into the gap. And re roof with something better than mineral felt.