Mr Punter

Can you have a mini pump station near the WC and pipe to the drain in 63mm MDPE? They are almost silent in operation and will probably only operate a couple of times a week. You would need to form a sump for it but ANYTHING is better than a Saniflo.

There are special pavers that are shaped to leave a 3mm gap between. The system requires special fines free sub base and pointing with a kind of grit. All very expensive. If your BC accepts normal kiln dried jointing sand then that will be good, although not permeable / SUDS compliant. https://www.marshalls.co.uk/commercial/permeable-paving-and-suds

If you get the insulation and airtightness right this should be fine. Electric towel rads in bathrooms should be enough. Cables for electric panel heaters is a good plan for when you sell.

He has closed the cavity with plasterboard. Probably much better than the usual EPS and plastic cavity closer.

When our neighbour got locked out of the house, the only way to gain entry was to smash a triple glazed window at the back of the house. It took a fair few smacks to break through.

The QS or contract administrator should be able to advise. Sometimes contracts need to be "determined" rather than "terminated". Any goods supplied and fixed on site cannot be recovered.

Good luck with the planning application. As others have commented, perhaps do not make PH certification a condition of your consent as it may not be possible or practical to achieve. It can be very time consuming to attempt to alter a planning condition, especially if the PH has become on of the main considerations in the para (whatever number it is now) approval.

Frame fixings https://www.screwfix.com/c/screws-nails-fixings/frame-hammer-fixings/cat840010#category=cat840068&productdiameter=10_mm&page_size=100

If there has been no subsidence I would not bother with insurance. The underpinning could just be viewed as improvements to foundations. Can you reverse the bucket on the digger?

I have never come across this. Is it available in large sheets and varying thicknesses?

There is a big water trap on a WC so you won't normally get any smells from it. More likely from the sink, where flushing the WC could be pulling the trap. Run a small amount of water in the sink and see if the smell disappears.

If you have MVHR they sometimes like a 10mm bottom gap.

On the screed is simple to do. You can always trim later if you need / want to. Make sure you set them so you have the head at the right height for your door and your floor finish.

Well that all sounds good. It is far better to check and know for sure, rather than worrying later when you have committed yourself. The path should really be 150mm lower than the DPC but if it has not caused any issues it will be fine.

Clean the materials and stick down with https://www.screwfix.com/p/sika-sikaflex-ebt-all-weather-sealant-grey-300ml/79250

Under the stairs then? Or with the shoes / coats?

I have found that even a well insulated cylinder can generate a fair bit of heat. Why not locate it in the deep cupboard next to the stairs?

On their front page they were quoting density in kg/m2. They also had no information on insulation performance. Avoid.

Hello William and welcome. Whereabouts are you building?

Use a telescopic vent with the air brick being just under the plinth brick. The vertical bit is only about 50mm wide so you can just cut the floor block to suit. Obviously you need to place between the beams. It does very slightly reduce the bearing for Marmox but it looks like the soleplate spans onto the edge of the plinth brick anyway. Make sure your ground level is 150mm below the sole plate / DPC.

+1 Insulation and airtightness need to be the priority. Spend most of your budget on this. If the oil boiler works OK, stick with it for now. If it does not heat the water, use the immersion. Forget the Sunamp and the log burner. Close up the fireplace.

I agree with (1) above. External humidity is high now and temperatures are warm. The MVHR cannot reduce that.

It is more the width of the footing. Extend it by at least 400mm on the low side and use some starter bars with hollow blocks, concrete filled. Add some weep holes low down. 800mm is no a lot but better done properly.

The render base coat and mesh is really sticky and forms a really good solid substrate to tile onto. We tried tiling onto the XPS and it just did not work.

I think that painted hardwood would look best. Other option could be aluminium.