Mr Punter

https://www.bbc.co.uk/news/uk-england-bristol-49028337 This shows a Premier Inn ablaze and a large part of it collapsed. I suspect it is timber frame as lots of their newer builds are. Quite why the fire spread through the building and caused such destruction I do not know, but it does raise some concerns.

The windows will have max dimensions for the type and I would advise making sure you are well within them. Fit them yourself and you will be fine.

I had a look at some images of this and they all seemed to come with a short bit of pipe attached. Not so with yours @8ball?

As far as I know the only way to "split" the title is to transfer part of the land. This may be possible if, say, the land is currently in joint names and you transfer to sole name or vice versa. You could also transfer part to a ltd company owned by you. You can do the transfer for nil consideration, so no CGT, but check with lawyer and accountant first.

I would not want the straps on the edge or the outside face of the outer leaf and rendered over. Would be near impossible to change the windows without wrecking the render. Why not have them fix to the inner leaf with longer straps?

You may find it useful to chat to the mortgage company. They would take a charge over the land (including your current house), then you can build your new house, sell the current house and repay the mortgage company from the proceeds. When you sell you will transfer that part of the land with the current house plus the outside space that will go with it and it will be registered under a new title at land reg. Your new build will be the same title as current but with the old house removed.

Are these the hangers in the other thread? I can see that the ones on the right are not in full contact with the ledger board. Continuous blocking pieces of the same section size as the joists run at right angles will fix any wobbles. Maybe do this 300mm from the iffy hangers.

@Grendel maybe ask Velox who they suggest as their system has been used on a fair few houses and doubtless many / most would have warranties.

I would replace the run and divert the whole length with 4 no 15 deg bends. It seems odd that it does not serve your property. Anything on your deeds, such as rights for others to run services over the land?

No so, you will easily get standard concrete blocks to go round with no problem and no need to cut the blocks. Given your diameter of 20m, the building circumference is 62.83m, so 279 blocks per course. The difference between the inside and outside of each perp join will be about 2mm and the maximum deviation in render thickness will be about 1mm.

If is their wall on their land you would not be allowed to attach to it without their agreement which they are not obliged to give. If it is a Party Wall you would need a Party Wall agreement or award. BTW did they object to your planning application?

I have found that with the holes drilled in the timber and the masonry 2mm bigger than the stud I am able to inject the resin, insert the stud, rotating anticlockwise, then fit the timber. You are right though - everything needs to be nice and straight.

I had our non approved chippies fit some windows. One developed a fault and after some wriggling Velfac came out and replaced it under warranty.

With chemical fixings it is very important the the hole is clean and free of dust. You can get kits specially for this but if you are on a budget blow down a piece of tube or a straw inserted into the hole (eyes closed) and an old toothbrush.

I think Guttercrest will do bespoke stuff.

If the company has gone bust you could try phoning them to see if any of their installers would be able to do the work directly for you. The Velfac style of window is a bit unusual as the inner timber frame and the outer aluminium sash are the same size. There is normally a gap around the windows of about 12mm which is sealed with Compriband tape. They also do not come with an outer sill as standard and if a sill is needed the windows are factory fitted with a timber packer and aluminium cills are soursed elsewhere. I assume someone has done some drawings / window schedule and accounted for this.

Is it correct that this is to do with condensation on the outside of the ducts, not the inside. as in winter the runs to and from the external terminals will be cooler than the indoor temperature?

The 5% reduction in material costs must be a consideration for the manufacturer

It will be fine. If we don't hear back we will assume the worst!

You may want to consider cross battening under the trusses with 25 x 50 or 38 x 50 at 400 ctrs for your plasterboard and your electrics.

I agree with @craig although they will probably be quite pricey / non-stock item at that width. BC like to see them and they are more robust than DPC.

Normally the answer would be no problem, go ahead, but the inside picture does not show a lintel above the window and it looks like the top has been infilled with brickwork built off the top of the window. I may be that there is a proper lintel above this, but it is hard to tell.

Why have you got one of those?

I would normally expect to use a bit (450mm ish) of concrete lintel under the steel. Cheap and will not crush.

I would not consider piling a DIY task. A while back on one of my sites the guys doing the slab formwork decided to move a small tracked piling ring because it was in the way. Rig toppled and caught someones arm. Could have lost a limb. He was initially OK but got MRSA in hospital. Piling requires proper design and safety planning and if DIY will carry lots of risk as you will not be trained and competent to use the kit. If you involve anyone else to help and you do not have the right experience you may (quite rightly) be open to criminal prosecution of it goes wrong.