Andeh

With UFH you need to assume constant heat to make the most of it, otherwise a cold slab just takes too long for weekend working. We put in two over sizes radiators, on their own zone off the ASHP. With insulation all round (except the slab), and within an hour it's toasty warm for that sudden bout of working or playing on there!

Any form of garage or workshop only do 2 part Epoxy resin/paint. The normal single tin garage floor paint can be extremely weak, with warm tyres simply peeling it off. Once you've made that mistakes the effort of removing it to enable a proper replacement is massive. Having made the mistake myself, it took nearly a dozen hours with a floor grinder to remove it all. Since then, I swear by 2 part Epoxy paint, and over 2 garages, daily used by two cars I've found it extremely resilient.

If you do manage to route out a new one, having two strip lights is even less shadows!! Surely the self adhesive ones only sit a few mm proud, and would never be seen unless you stick your head in the cupboard?

It's sad, but I do see it as a tax on stupid people. Better they learn their lessons on a £xx posh fan, and feel cheated, mugged off & embarrassed then when they fall for a dodgy email and take a £xx,xxx hit which the bank then refunds - at the rest of our expense.

Id be looking up if there are any sink hole type construction projects in the wider national area. Surely the approach to resolving those is not dissimilar to what you need to achieve here? Id be looking for engineers or companies which have been involved in those sorts of projects, and see their views on it.

But with batteries, smart grid, vehicle charging, vehicle2load, import/export and smart tariffs.... The peaks and troughs of weather dependant generation can be smoothed out quite easily. Why form a strong judgement, when you only understand part of the topic?

Please let us know how you get on!

I went through the same worry OP, where I wanted full flush and it's about 5mm low floor to sliding doors inside, and 15mm outside. The outside as we added a third slider which added a lip as the door sits over it's track... And I forgot to check. Haven't thought about it in ages....

Especially the pesent isnt dead enough, and has just enough energy to make a run for it. I never wanted the ruddy cats in the first place.

You're already in the top 0.1% of air tight homes, spending £2,000 (and £2,000 of TF money for use elsewhere...) to enter the 0.01% of homes is not worth it IMO. Future sellers won't care, friends and family won't care and realistically you'd never notice the difference even if you really really tried on a really windy day. The second anyone opens a door you've undone several hours of airtightness anyway. Ours is at 2.7 (no sniggering at the back...) as a hugely volumetric bungalow with several sliders everywhere... And despite wibbling about it for years, and being obsessed with trying to seal everywhere that I could.... Its fine...

That is lovely!

Sorry to hear it OP, these houses can be such a massive emotional and physical heavylift.... But the shitshow will be temporary and the satisfaction and enjoyment is a lifetime. I promise you it is all worth it in the end, but you do need to smile and endure.

We did, is just stick 20mm PIR against the external wall, and ??mm at the bottom of the cavity and then back fill with concrete. That way you've mitigated the worst of the thermal bridging and have a strong support throughout. Wish that's what we'd have done, but I was away with work and due to 2.4 x 8m sliders they backfilled entirely with concrete due to worries about the weight and movement destabilising. It's held firm, but we do have a sizable thermal bridge now.

Natural movements between the two supports would be more of a concern then the raw bridging abilit I think. Slight cracking and debonding on one side could be an issue?

Great write up! On my to do list ia find a way of both buttons doing a full flush, and ensuring the full flush is indeed a FULL one. Young kids means they only press the button once/lightly/at random, and the waste never fully goes.