Mr Punter

I would get rid of that arrangement and have an external gutter and downpipe.

Raised platforms are often an issue if they overlook other private gardens. Had you repaired this in stages, you may have been OK. If they issue an enforcement notice you can appeal it.

Which is why it also needs to be less than 0.002 x span, or are you saying 8mm is too strict for longer spans?

That is why I like to specify a maximum deflection of 8mm or 0.002 x span (whichever is least).

Tiles, adhesive and flooring. We either borrowed a pallet truck or used the one from the pallet delivery company. Any edge more than 15mm will stop it dead. It is a bit like pushing a car. I would not go for this to move a load of blocks 50m.

Most of the regs have a section for conversion / change of use. Often it is do not make it worse. Mostly more lenient than new build. Best go for a full plans application, rather than a building notice.

You will be fine if it is level or slightly down hill.

Often 72 blocks in a pack.

I am pleased to see people specifying 8mm max deflection. If you need to install rigid pipes or ducting through these, do it NOW. You could blow in thermal insulation - either fibre or polystyrene. If you do the latter you will not be able to have PVC cables in that zone.

I have borrowed a hand pallet truck in the past. Lots of shops have them. Used it to move an annoyingly parked car that was blocking the way and the more standard pallets of materials. They weigh a fair amount and need a flat surface. As you know blocks don't always arrive on a pallet.

Quite a few composite windows (like Velfac and Ideal Combi) have an external opening sash that is the same dimension as the internal fixed frame, so you need a reasonable gap to prevent the sash fouling on the brickwork or external cladding. I have seen Compriband in gaps of 20mm and it does not look bad.

Sadly there is no easy answer. You could let the weeds grow and spray with a very strong glyphosate mix several times in the growing season. May take a few years. You could concrete the area, as the horsetail will not break through decent concrete.

It just won't can't happen. I am doing some new flats and I will put in gas combis. No chance of ASHP and SAP will kill me with electric resistance heating and the flats would be more tricky to sell. The running boilers on hydrogen gas sounds like dreamworld too.

Not worth it. Save the money. The ties will be the equivalent of 100mm x 100mm area and as they don't go from outside temp to heated space they will have almost no impact.

The screed looks fine. Your flooring fitter may want to prime it before laying the Karndean / LVT.

I don't understand the insulation unless this is going to be heated. Rendered blockwork is probably cheapest. You could add IWI later if it is needed but what do you propose for the floor? I think the roof would be the most important element to insulate if you want to prevent condensation dripping.

I would want to extend the main if possible. I have a block of 8 converted flats and noticed the other day that they are all served by a single 15mm supply, teed off to 8 meters!

I assume the developer ltd co will go skint but I wonder where the house owners will stand? I would think the directors may face some personal liability. Did the architect have any say? Very odd that this was such a mammoth blunder. The conveyancing solicitor will normally want to see that all planning conditions and building regulations have been complied with before completion of the purchase.

If the wall is nice and dry the OSB should be fine. I would not bother with a vapour barrier as I am not sure what vapour flow you would want to stop. They are often used on the warm side of insulation to control warm moist internal air from condensing in the insulation or the structure but this is not what you have as it is an uninsulated party wall.

Yes radon barrier goes right over the slab. The green polythene is not a gas membrane. It looks like a separation layer to isolate the screed from the concrete so you have an unbonded screed.

That mesh is heavy duty. Space your mars bars and deck chairs at about 1200 and you will be OK. I hope you have a machine to lift the mesh in.

Funny that readymix concrete is not in the same position.

Just do whatever you have to. Apply later for a revised entrance location and fight about that once you have your house agreed.

That looks like a haven for rats. Unless the ground conditions dictate piled foundations, just do strip footings and raised beam and block.

You will need either to elevate the building or have a sacrificial floor, like parking etc. For 1m I would just elevate and where possible build up the surrounding ground levels. Only 4 courses of blocks so no biggie.