Mr Punter

Thin screed on insulation will crack up. If you want a really thin layer above underfloor heating pipes you can use some of the interlocking cement board products like ScreedBoard20.

Oh well, you can always render or pebble dash if it looks crap!

Yes you could fully fill your 200mm with Platinum EPS beads.

On top of insulation it needs to be 50mm liquid, 75mm sand cement. The thin layers of self levelling would just be for evening out existing concrete floors.

It may be good to dig a pit and expose the existing foundation. Unless you have experienced subsidence the single storey extension foundations could be made the same.

The ashlar quoins and window surrounds look very posh. I look forward to seeing these completed.

Yes this is acceptable.

If you have not done this before it will be much less painful just to get a price. £7,500 works out at £220 per metre. Is that price all inclusive labour, materials and muckaway?

Would sacking the builder kill you? I would have let him go over the 120mm mistake or made him swallow all the costs for remedy and prolongation.

Best with treated but most firms offer the option at a price, so ask them and you will have a like for like.

They may find that they can apply a studded membrane to their side of the wall, form a channel at the base for the water to escape and build up a metal stud wall in front. They would lose about 80mm from the width of the garage. I notice they have an overhanging gutter. Is there an easement for this?

Yes you need to apply to have the condition varied or removed https://www.planningportal.co.uk/info/200126/applications/60/consent_types/11

I have done this with stone slabs on a bed of sharp sand / cement a bit wider than the slabs, haunched around. If the porcelain is thick and non-slip I don't see a problem.

Was going to suggest different rooflights... Doh!

Worth a call to the manufacturer. They can ping you a manual. They could wriggle out of warranty if it is not to spec.

I think you would need to line the underside of the rafters with 30mm PIR with a VCL. Ventilation could be above Tyvek type membrane, ridge vents, soffit vents and rafter trays, tile vents etc.

I seem to remember reading the cold bridges only run for about 1.5m along the walls and not worth doing more. Also, you have to consider having a step in the wall, re-doing the skirtings and loss of internal space. My feeling would be to do just external walls. Does warm batten mean battens on top of insulation so you have service cavity?

I have never known muckaway to be less than estimated. Does not seem to matter how much more you account for bulking, it always comes to more!

@nod I think it could mislead others when you quote your build costs, as you are a very experienced contractor and you and your partner did all the work yourselves. The OP is looking at getting trades in and should budget at least £1,500.

If that pipe just connects to the soil system you def need a trap .

You will need to apply to have the condition varied or removed, giving your grounds for why it does not accord with policy or whatever. If they refuse the application you can appeal it. It is unusual to have ALL pd rights removed. Often just "No enlargement, alteration..." etc. Post the wording and reason and someone may give a better reply.

Not crazy but with that sort of figure I would get 3 quotes.

Perhaps google "fluffer"?

Need to get the customers in the right frame of mind somehow, I guess...

You main points seem to be: 1. Availability and safety of parking. The solution would be to provide on-site parking and turning within the application site. 2. Safety for road users due to increased traffic. Seven or ten flats will not make a large impact on safety. Unless there were proposals to build an estate of, say, 30 houses I cannot see any issue. Do you have any other agenda?