Mr Punter

I think the concerns are valid. Unlike traditional formwork, with ICF you are not able to inspect the concrete as the shuttering is never removed. Why not get this priced in steel with concrete for the basement? What is the preference of the SE? I have done a basement in ICF and we used a type C waterproofing system (internal drained cavity membrane) with a pump. No complaints from the owners.

Even as is this would be a dream house for most people. Are you going to demolish entirely including foundations, or modify what is there?

OK well hopefully you have now established the cause. Before you put it all together again, can you get someone to do a proper design and spec for you to follow as winging it has not worked so far.

Hi Tim You have never self built before but have posted twice on the leading self build website promoting the same company, who I can only assume you have never used. It looks like spam and smells like spam.

Perhaps take up the paving just around the rooflight to expose the membrane.

Josef Fritzl

Very odd that consent was granted with the tree in place. Did anyone produce an arboricultural report? I think the tree has to go.

We have done similar but using coach screws, leaving 60mm plus the head of the screw to go into the wet concrete.

Yes I have read that not having a drained and ventilated cavity can lead to damp getting into the frame. I understand that in Canada they have had real problems with this several years ago known as "leaky condos" which has a Wikipedia entry https://en.wikipedia.org/wiki/Leaky_condo_crisis

Hmm this is just one tree so unless it is of national importance I cannot see why it can't be worked around. Otherwise you can bridge over it. Don't do an application where you are short of available height as it may come back to bite you.

Are these soakers that go under the slates, with a lead flashing that gets cut into the stone and dresses down over these? If so, it is probably OK.

The pumps work at a fair rate so make sure you adjust the float switch so you do not exceed the capacity of the Klargester. You will need a high level alarm with a sounder indoors.

I fitted one with a 3" pump to avoid issues with solids. The tanks are fairly cheap so bigger is better, but make sure you backfill with concrete. Our neighbours have a dual pump system and they often have breakdowns, whereas a single pump is far simpler, but also bad news if it fails. If in the event of a failure you could pump to a nearby drain with the replacement pump you would save a load in call out charges.

Looks like it was designed by Escher!

What is the outer skin? If it is brick you will still need DPC and 150mm externally. Even properties with basements have DPC. The level thresholds have a drainage channel in front of them and this helps prevent splashing from rain. Also it is windows and doors in these locations and they do not soak up water or stain like brickwork / stone. You can reduce the 150 to 120 without any issues as long as the surrounding surface drainage is properly designed. You can always have a doorstep apart from the main entrance.

If you have a ramp for wheelchair access you cannot have a sheer drop either side of the ramp, so you either need edge protection or a slope to the sides. Imagine you are approaching with your eyes closed, you are a bit fragile or a wheelchair / walking frame user and are not that familiar with the route, as that is who this is intended to cater for. The solutions vary widely from site to site. As per @nod submit your proposal to BC or discuss on site with them.

If there is enough fall you may want to have 400mm from FFL to pipe invert and this will allow for whatever manifold to be sunk in. 100mm screed seems a lot so maybe go 75mm with thicker insulation. The floor will warm up quicker.

Perhaps they need a turning area for bin lorries and emergency vehicles.

You did well to cut a straight line in that stonework. Must have been a nasty job to do, especially so low down.

Is this for flood resilience? If the flood risk is that severe you should look at locating the kitchen upstairs. If not, just go with normal units, where you will get a huge choice at sensible cost. Kitchens only last 15 years before they look dated, so if you get flooded, just chuck out the damaged units and buy new ones. If you have stone type worktop this can be reused if you stick with exactly the same layout. Other flood resilient measures would be where practical, to site all electrics above EA suggested flood level, build ground floor internal walls in concrete block finished in render, have ground bearing concrete ground floor, install a sewer non return valve in a 1200 diameter chamber.

Can't quite picture this but it is not advisable to leave a long capped off dead leg as water can stagnate in the pipe. Also, if you do a below ground connection, try to locate it so that if required in future it can be exposed and replaced.

A while back we were contacted by a firm who offered to get us Capital Allowance tax relief because we owned some commercial property. They sent someone round who did a survey of the building - a fairly poor 1950s office -and they calculated the value of pipes, wires, air con etc. and lodged a claim with HMRC. We only bought the building with a view to demolish but were able to claim tens of thousands in relief for works carried out by previous owners.

You need specialist tax advice here, not the opinion of us lot! It is quite an intriguing loophole though, especially for high value purchases. Oddly there is nothing to say your woodland needs to be anywhere near the house.

You will need mesh in the concrete and maybe extra density XPS. Could be a job for engineer calcs. They are often cautious to allow for things like jacks which can be a fair point load.

You could get one with a side opening door. Here is a cheap second hand one: https://www.ebay.co.uk/itm/Gaggenau-Oven-BO250-111-60cm-Stainless-Steel-Used-only-a-few-times-Immaculate/292725962883? Actually still fairly expensive, but fantastic ovens.