saveasteading

My logic is that other things go wrong. Eg one toilet in my house sometimes doesn't clear. It needs a shove and all is well again until another time. I suspect it is over use of TP and not a scientific thing. On one job a long drain blocked when the occupier moved in. The drain had never been used officially. It turned out to be a sanitary product in mid run. It had run out of speed. Then it affects subsequent use. ie low use can cause issues too. A neighbour had 'stuff' appearing in a downstairs wc from the one above. Was all according to regs. Ie other things go wrong and I'd rather it was outside and simple. But do it to regs and it will mostly work and always be roddable.

I prefer to get the pipes out by the shortest runs , and with minimum complexity. That makes more pipework outside in your case, but reduces risk. It often results in the outside drains starting higher so the outside trenching isn't so deep. So your utility drain would go straight out, perhaps combined with the bath , and your wc another line by the direct route. I see a note for a wc next to the bath, but don't see what it is for.

It's just that I did a search and that came up, showing it is common. I'm pretty sure we sourced ours through a paint merchant, and it was not a mass market make.

Leaves me wondering why the 10th and 11th are of no interest. Something very simple perhaps.

And also you are there for any questions arising. Usually they have a suggestion and usually it's sensible., but you will be part of the process. And you can nip to the BM to get what will sort it. Btw I'm relating a fraction of what goes wrong / causes other issues.

That will be so annoying but I agree with the above advice. Also consider that there will be furniture and other distractions. Anyone else walking in there now won't notice and perhaps wouldn't anyway, and when it's furnished, even less so. But overall, you either micromanage totally or you don't. You've done all you can and it would have been more extreme without. Mostly, remember it's just you and me who are bothered by this. Otherwise the manufacturers would be using bigger patterns and fewer features. Do something elsewhere today.

I'm only saying what I did. This was a new commercial car garage with hoist. It worked nicely and our client saved many thousands. I'm guessing, but 12 cars a day? In other garages we used v expensive resins and they worked too, with a downside of being thick and difficult to seal at edges.....and expensive.

I don't agree with that. we need legislation and control of it. Yes there are also specialists who write themselves in to planning control. The archaeologist or naturalist who says that it may be a sensitive site and that they themselves should be paid to research further. (I'm not mentioning these at random, and it bothered me a lot at the time) But a good planning agent or designer can cut through some of that. Also these costs come off the land not from the builder. An acre of farm land in SE England is worth £10,000. Get planning permission and that becomes 800k to £1M or even much more. £50k may go to the community. Someone's garden worth £30k to the house value sells for £200k with permission for a house. I'd be interested to hear the equivalents around the country. These windfalls are where the money goes. Another discussion might be on why the big sites sell for so much money when years before they were worth next to nothing... is there a value below which they will not stoop? and is there a value above which the developers wont increase. None of them.

I had a summer job scraping manure out of the internal joints in an old rural stone building. Guessing it had been there 100 or more years. It was very effective material. Ahh not that kind of muck?. But everything we use is made of treated ground or dead trees. Even the modern materials are oil based, so dead algae remains and packed out with some sand. It's all we've got!

@JKaines It looks to be well considered. Unfortunately I can't see a commercial value other than the philanthropic one of letting the world have it free. If a business was to copy it then so be it.. I'd be interested to look at it critically (any suggestions would be foc of course) if you care to send the files, and maybe build my own garden building to test it. I especially like the idea of zero waste. what lengths are the timbers?

That was 50 years ago. I still have mine but it is a museum piece. No, you just need a water level. £15 at screwfix. I haven't looked elsewhere.

add to that their own preferences, prejudices, and making it interesting for themselves more than for you.

Get them to sketch it or describe it enough for you to draw up. To scale ad with dims. I'm afraid for you if you don't have drawings. It can work but there's a lot of risk.

Before they start check they have the drawing. Ask them if there are any issues arising. That is their moment to explain that they disagree or agree to build it as designed. Then you have an agreement and they work to it, or you don't and you have to manage the situation. You'll often find that they haven't got the drawing, or that your workers are not the one you agreed the job with.

Your plumber may be limited in choices if they use a single merchant, as many do. Best discuss with plumber ASAP. Try talking to Trade Underfloor Supplies or similar. They supply the whole kit and I'm sure many plumbers get it done this way. But check you get the grant benefit.