Mr Punter

Euphemism?

You can break off any big lumps or ridges with hammer and bolster. Doing the insulation in 2 60mm layers will help it lay flatter.

A pitched roof is far less likely to cause issues than flat. Natural slate will be cheaper and less defect prone than zinc. Timber cladding often looks cruddy in a few years and flammable cladding is best avoided. The glazing is excessive. It will cause overheating in the sun, higher heat losses in winter, extra capital expense, unpleasant reverberation and glare.

I don't think you will be able to get hold of this for a small area. Probably min order of a pallet and you may need more than 1 size. Just use firrings.

Unless this is for occasional use in a small room like a bathroom it will be prohibitively expensive to run.

So to clarify, are there separate systems for foul water and for rainwater? You may struggle to connect to clay pipe that is encased in concrete.

Ask your floor designers to factor in the tank. You need to be sure as it is a long term load.

I think they are correct. The work on the ground floor compromises the upstairs as the kitchen is open to the stairs. They may ask for additional smoke alarms as well.

The bonding adhesive is fairly sketchy. I wouldn't want to core a 4" hole after filling.

Yes when wet they are probably as thermally inefficient as solid concrete but these are internal walls so should not apply.

This is now mineral wool batts instead of rigid PIR. It is nearly always full filled. As it is single storey and sounds like rendered the risk of moisture transfer is very small.

Another vote for loft mounted PIV and Meaco dehumidifier.

That seems fairly standard. I think the reasoning is that you will notice the lights not working in the event that the circuit fails and the battery backup will mean the alarms still function.

Funny place to have a roof window unless it was going to be converted. If it was just for natural light they would have put a smaller rooflight between the rafters. Leaving it as a bodge was not great.

I think it is any part of the building within 2m so eaves would be included. The slab would not matter.

I would just fit the rooflight as is. I cannot see why the LPA would seek to take action.

It works like this: Height (m) Lambda (W/mK) R-value (m²K/W) U value Thermoblock 0.065 0.05 1.30 0.77 Aircrete 7.3N 0.215 0.18 1.19 0.84

It is very expensive. Essential that the subfloor is completely dust free, which is difficult to maintain unless you do the cutting remotely or with a posh Festool thing.

Glued will feel more solid but either will do. Either way, leave a decent expansion gap around the perimeter.

I don't know what the need for the floor to breathe is all about. Suspended timber floors often had outside airflow under to help protect the timbers from rot. I don't think the batten gap on the room side will do any good. 6mm ply is not stiff enough for a floor. You could lay some thin 10mm XPS and overlay with chipboard.

I don't understand the 45 deg angled screws. With the washer head they won't even sit nicely.

Obscure glass will be fine here. It is for light and maybe ventilation. Also you don't need to concern yourself with cleaning it.

It looks like it is flaking. Leaving it may cause further issues. Can you get it done now?

It may be the contamination risk from a leak.

I understand aircrete is about three times poorer, but it is 3 times the height, so by the time you are at the top of your insulation / screed layers they are roughly equivalent.