Kelvin

You’ve not really explained why you think vented is preferable other than your familiarity with it. The requirement for an ASHP has likely made the decision for you however. On the wet UFH upstairs comment. Many of us on here haven’t bothered taking the wet heating upstairs. Some folk pipe for it a lot don’t bother and just have sockets in the right places for panel heaters or such like in case they are needed on very cold days. Electric UFH in small bathrooms is an easy and straightforward install that minimises the depth of floor build up albeit there’s still quite a bit of extra depth (insulated board, UFH mat, screed, adhesive, tile) You shouldn’t really need to heat the room with it, it’s more to make it comfortable. More importantly you want to isolate this from your wet heating system anyway as your likely to want to heat the bathroom outside of the general heating season. We took the wet UFH into the downstairs bathroom and this was a mistake in hindsight. We should have just used electric UFH in here.

Welcome. Spend a bit of time reading the forum. Invaluable. If you look at the forum topics it will lead you through the various stages in terms of information and questions folk ask. If you’re employing a PM won’t they have a project plan? I just used a simple spreadsheet and an action log but about half way in i stopped updating it rigorously as there’s not enough time in the day to stay on top of everything. I did kinda document a fair bit on here for three reasons. Firstly it helped get advice on how to address issues. Secondly it helped me think it through by writing it out and thirdly it was cathartic. The encouragement from the other forum members was good too.

I can’t emphasise enough how flexible any manifold based water distribution system is. As @JohnMo says the ability to commission everything one tap at a time really helped us.

It’s the Emiter one I have. The compression seal on the door is crap and it fell off quickly after installing it. It didn’t leak with this missing but I’ve since replaced it. I also sealed it both inside and out around the base as water was getting in. Even for single phase I’d recommend the taller one especially if you are going to use it as a temporary supply so will have a CU and some sockets in it.

It’s very easy to use as much water showering as you do in a bath.

The pipes and they way the joints are made are more robust than the other systems I looked at, you don’t need to worry about scratching the outside of the pipe when pulling through the building albeit I was still careful, the manifolds are very neat and I had limited space in the plant room. The pipe is less flexible than the Hep stuff so you need to be careful with how you route it as pushing it around other stuff isn’t easy so I put it in first.

I used the Rehau smart manifold system. It wasn’t cheap and requires a couple of special tools to form the joints which the supplier hires out. Very happy with it. It’s very neat, the joints are good, the pipes are very robust. It’s very quick to install. Took a day to pull all the pipe through the house and connect to the manifold. I made one mistake and cut the pipes too short in the utility room so was unable to form them through the wall so I ended up having to make two joints in the wall.

It’s the exactly the same one I fitted for single phase. It’s massively increased in price though as I paid £495.

You said you can fit the AAV so that it’s >=200mm therefore why not just do that removing any future concerns. I had the same situation although my AAV is inside the coomb. To meet the right height I brought the wall out another 100mm which then gave me the height I needed. I could have done what you’re proposing but decided just to follow the guidelines.

There’s a lot more in a house that those elements. I’ve built a house I know how much it all costs down to the screws and nails. Good luck.

I don’t see how a house that will be worth £1million will only cost £170k in materials.

I kept some off cuts to have a practice on.

I used diamond dust core bits. Start at an angle. You won’t break the tiles unless they are thin and cheap.

Apart from the windows the rest of it is easily fixable so you know you can significantly improve it. My first test result was pretty reasonable and was able to significantly improve upon that for the final test. (0.98 to 0.4) so was money well spent. Doing the air tightness was the bit of my build I enjoyed the most.

Our Lindab metal guttering was dearer than the zinc quote. Neither was that dear. This was driven by energy prices apparently as zinc takes less energy to make. What the supplier told me anyway.

SIP builds are essentially timber kits with PIR. Loads of them in Scotland many of which are timber clad. You don’t need to worry about the strength of them. On the acoustics. I have a SIP metal garage where the insulation is 80mm thick. Now you can’t compare that directly with a house but whatever noise is happening outside is almost as loud inside. Noise attenuation doesn’t rely on a single material anyway and making that material thicker doesn’t necessarily help either. You need multiple materials and for it to be well sealed. SIP houses I’ve been in haven’t been as quiet as ours though.

A few friends and I regularly drove each other’s cars on various race tracks around Europe and the general principle was you crash you buy it.

You need something that works and is worry free and gutters seems the easiest solution. On the ‘what gets installed first’. I had exactly the same debate. The consensus between the metal roofers, the membrane installers and some other advice was the membrane gets fitted first. The problem this creates is maintenance down the years as you can’t get to it.

Our retaining wall is just built with concrete blocks and no facings or cladding. I quite like it. Looks rustic (ok unfinished) but it’s not the eyesore I thought it might be. We were going to clad it to match the house but have changed our mind. If we do finish it, it will be in facing stone. I’ll probably do that myself though.

They don’t really work in heavy rainfall. Wife’s uncle has them on his Huf Haus. Nice looking things but slightly impractical.

Exactly. In fact the compromises have forced us to make decisions that have resulted in a better outcome. Necessity being the mother of invention.

Standard trench using insulated foundation blocks with insulation on outside and inside upstand and concrete slab.

Ours are formed from Jakoboard. It was hard trying to find formed alcoves to fit the space. They are taped, tanked, sealed then tiled and sealed again.

Think in terms of whole tiles and plan it back from there. These are ours. Are you tiling it yourself? If not my tiler didn’t want me to make the alcoves all he asked was for enough space be left behind roughly where it was going to allow him to dwang it and give him some leeway when making it. Remember it needs a fall to drain any water. Our tiles were all 600x600