PeterW

As others say - 110mm ideally but minimum 50mm.

3m is pushing it - most are either 1.8m or 2.4m at best. With ordinary concrete posts they will need to be in a long way to cope with the wind load of a 3m panel.

After recently doing a conversion that basically swallowed an old double garage I entirely agree ..!! The hassle of keeping an old structure that looked sound on the face of it (built in 1996) which then was found to be out of square in most directions plus need a complete new roof etc to tie into the new, and notwithstanding the VAT issue of a conversion rather than knock down and rebuild means that I would seriously consider taking any structure down these days where possible. However on the flip side, like @Cpd I really do enjoy the challenge of stripping back old buildings to their bare shell to see how they were built and working with them - that’s probably just the slightly sadistic side of me though ..!!

The stainless ones are designed for retrofit - not sure how you’re getting to £900 as I use the Dunbrik concrete ones and they usually end up at about £450 for a 2 storey house minus the pot. You will have to build a full brick or block outer to line with a stainless liner so you’re saving nothing in reality. Do it right and do it once - ceramic or concrete will last the life of the house.

Also think about adding a drain tap on the end of each manifold. Makes draining down easier.

keep an eye out for Videx stuff on eBay. It’s eye watering new but is really well made. I picked up a returned unit with a damaged internal phone for £75, and then got two new phones from eBay for £20. Total cost of all the bits would have been £7-800 at normal prices.

Cut a hatch about 450mm square and then insulate with the plastic/ foil wrapped fibre as you can shove it into the edges with a broom. Head torch and a mask are a necessity...! Then when you’re done, pull the last layers over the hole you’ve made and screw the carefully removed panel back to some battens you’ve screwed around then outside edge of the hole, fill the gaps and you’re nice and warm in winter ..!

You can get a simple steel calc done online for about £40 - peace of mind doesn’t normally come that cheap !

Soakers can be done in code 4 - for the sake of 0.5mm thickness it’s not really much of a saving. Also stops cock ups of the wrong product being used.

Only seems to be available in white. Glass to tray then spacers and CT1 clear would be my choice. Then pull the spacers and fill the gaps when dry.

White CT1 can discolour but never heard of BT1. Are you talking about the floor to glass join or the wall to glass..?

What sort of wall ..? Does it need to be watertight all round, or is it just decorative ..?

GRP valleys are fine - they really don’t leak if you get the decent ones not the cheap ones. Lead is better but you need to cost in valley boards and time to fit so is 4-5 times the cost of GRP. You’d be better with a ventilated ridge system and using a fully breathable membrane. Cromar make a couple of good ones, as do the usual suspects such as aTyvek and Protek but I can’t see what doubles the price. Be aware though they all have a maximum exposure time of 3-6 months depending on the manufacturer so you need to have your roofer planned and booked before the membrane goes on. All lead will be Code 4.

Steel piles or end driven concrete piles..? What is the spec of what has been agreed ..? And what is the ground you’re on - have you considered an insulated raft..?

Beer can chicken ..! Excellent ..!

Yep it’s called a ducted cassette ... and they are not cheap and need an external unit otherwise you’re just heating the localised air. Shame you can’t buy the US window units over here as they are ideal. Edited to add ... apparently you can buy the single room external coolers but they need a big hole or decent sized window ..!!

VTac panels are my weapon of choice - I would put 6 No. 600x600 panels with ceiling mounts across the space. Can be had for sub £20 for the panel plus £6-8 per flush mount frame. You’ll be able to do operations in there it will be so bright ..!

Welcome ! So first observation is that you have a lot of bathrooms ..!! And none appear to have a washbasin which given the size of some of them you may struggle to get one in. Suggest you look at the ground floor and define the spaces you have as what will be used for as the bottom right doesn’t seem to have a use..?

It is cheap for a reason ..!! It’s a pig to cut and fit and used on big commercial jobs where ease of access isn’t a concern as they can put it in when the shell is empty.

Rinus are good but wider than that area. Burton Roofing in Sheffield have decent stock and pricing - depends what you are after

Welcome..! There are plenty of small scale projects on the go here - so ask away !!

English regs say 300mm down and you’re fine to wall mount. Pretty sure the Scottish regs are the same ..?

Sand has a surprising impact on the mortar - we use a “grey” Lincolnshire sand rather than the red Mansfield sand as the one that comes from further west tends to be quite grainy and doesn’t make as good a mortar. With new bricks then a 5:1 is normal round here, but for reclaims (which we do a lot of) then we use 5:1:1 sand cement and hydrated lime.

I would not use spray foam here as it’s overkill and not what it is designed to be used for. I would let the builder put the spreaders in, then re-lay the floor. Then from underneath fit rockwool tight under the pipes and compress it slightly by capping off under the rockwool with 50mm of PIR (Kingspan or Celotex) and then use battens screwed across the joists to hold it in place.

Welcome That is a very poor level of insulation for floor - new build standard is 0.11 from memory. Can you get under the floor once the UFH has been laid..? This may change the approach to how things are installed and in which order.