Mike

If the outer leaf of the house is non load bearing, then another option could be to confine the steelwork to below the inner leaf, then use Ancon brickwork supports (or similar), which can be fitted with thermal breaks, to support the outer leaf.

The positioning isn't ideal as the air doesn't pass through the kitchen. My guess is that the BCO wouldn't question it, but they may.

Yes, several reasons! It's much more resistant to airflow than regular duct, so the fans will have to work harder (using more energy, so also louder); condensation can gather in the undulations leading to mould growth; it's not very resistant to being crushed, punctured or ripped; due to these problems it can't be really cleaned internally, should that be needed. The only legitimate use is when using a very short length - e.g. 150mm long for 150mm diameter duct - to connect rigid duct vertically to the MVHR unit, though that seems to be rare.

A wet system is simple and about as future-proof as you can get. It should last for decades and you connect it to almost any heat source, though an ASHP is the obvious one to go for now.

It's certainly possible, but demolition isn't much of a laugh to do and it will probably take you double the time. If more people thought that way, life (and buildings) would be much better :)

If your they're all happy, problem solved! Just make sure that it's done properly, so that the block is actually supported beneath.

Maybe you can spot the problem from these sketches? This is a vertical section, with the foundation at the bottom. What you appear to have is something like the one on the left. What you should have is the one on the right, or some other variation that supports the load bearing wall right down to the foundation.

You're right - In France that seems likely from next summer. According to the Regulator: To take account of changes in the electricity production mix and the abundance of summer photovoltaic production, stakeholders are being consulted on the gradual adoption of summer afternoon off-peak hours from August 2025" Original in French: https://www.cre.fr/actualites/toute-lactualite/la-cre-consulte-sur-le-futur-tarif-dutilisation-des-reseaux-publics-delectricite-turpe-7-transport-et-distribution-pour-la-periode-2025-2028.html

From the last story: Gov. Gavin Newsom's advisors and those who manage the state's electric grid say they are working to reduce the curtailments, including by building more industrial-scale battery Storage facilities that soak up the excess solar power during the day and then release it at night. Which is sensible, if overdue.

Theoretically that helps, but in practice they may still crack.

A non load bearing block partition can be built on top of a beam & block floor if the floor designer has taken the loads into account in the design (often requiring extra beams) A load bearing wall can't be built off a beam & block floor because the loads would (normally) be too great A beam & block floor can be built a load bearing wall and be supported by it (i.e. the wall is supporting the floor, not the other way round). Your builders seem to be making a sandwich of a wall that's vaguely attempting to support a floor that's supporting a wall, which isn't acceptable.

Aerated blocks just tend to crack, even when laid in accordance with the manufacturer's instructions, including the correct mortar mix. Better to avoid them if you can.

You've got it :) Unlikely - it's a standard construction.

This. The floor supplier should have been sent drawings showing the foundation & the position of the piers, and the supplier should have sent back a plan showing where each beam should be positioned. And your contractor should be following that plan.

It's theoretically possible, but may make airtightness harder to achieve and, of course, you loose the benefits of the insulation downstairs. It may be possible to buy the same cornice pre-made and install that, but if not then there are companies that will cast an identical replacement for you. Standard plasterboard is OK provided you don't paint it with regular vinyl paint.