Mr Punter

@recoveringacademic I just want to check that you are aware that the proposal from Cullen only allows an extra 25mm extension to each end of the joist - 50mm total. In your earlier posts on this topic you suggested that the joists were 100mm short.

Have a look at the contestable elements of the £40k quote and see if you can get it done for less. Also have a look at @JSHarris's experience with a borehole water supply - not always at all simple.

Substructure is all the parts of the building below ground. Unless you plan to leave the site as is for several years there will be no issue with freeze / thaw.

Why do you need to pump the water out? What are you backfilling with? If this is all substructure, water will not be an issue.

Did you diy these? Any chance of some photos inc with doors / drawers open & closed?

I think your architect may need to get involved. Probably BC are agitated as you have a strongly ventilated cavity. One simple idea may be to apply a fire resistant breather membrane in place of the standard one. MBC could do this in the factory and I doubt it would be too expensive. I would say no to Promat etc in your situation. I have done several TF projects with cladding - timber, slate, render on carrier board, cement siding etc - and have never been asked to apply fire resistant sheathing. In the event that you did need a FR sheathing, there are some fairly cheap MgO boards around. The only time I have had it specified was for multi storey adjacent to other buildings and it was a during construction precaution (in case of arson etc) applied to the end walls and some of the party walls near the end of the block. Not a building regs issue but a "best practice" H & S.

In the event of no deal I think it is likely that the BoE will not want the economy to tank, so more QE which will help inflate asset prices. Although the £ may fall, unless you hold another currency or gold, it will not make things cheaper in £ terms, in fact you may need more £ to purchase the same item.

Don't rule out a conversion. Round here there are police stations, chapels, public WCs and other underused public buildings which get sold off, some of which may not suit residential but would be ideal offices. Make sure it has parking.

But the proposal from Cullen only adds 25mm

But you would not need to double up the wall plates - just 25mm each side to match the add-a-lump-on-to-the-end-of-each-joist solution.

OK I misunderstood having read that you were doing the BC application bit by bit. It is mainly snow loadings with a roof. For you I would not rule out the 20 mate scenario though.

I think you need to just give this to an engineer as Building Control will want the structure signed off by an engineer in any case. Why not just supply BC with a full set of drawings and spec then you can be sure that as long as you do what is on there it will be 100%.

I think it depends on ICF, pour height, concrete core thickness and reinforcing. Your ICF people / engineer should specify the concrete. Hopefully your pump guy will not spend too much time pissing in your ear and trying to get water added. Let them all know you will be doing slump and cube tests on the concrete.

Ask the designer or call Simpson Strong Tie. Maybe made to order.

I think you could just double up the timber ledger on the wall. Just like when you trim a stair opening.

The proposed solution shows 2 vertical pieces and new 3" block. The photo on @recoveringacademic's original post just has a single upright and I can't see how this will work. Maybe just screw length but a new drawing may be needed.

The old Perko type closers were dangerous door slammers. Normally removed by the first occupant.

Let us know how you get on... I really enjoyed the YouTube stuff with Larry Haun recommended above by @scottishjohn

Yours looked a bit better as it was the full height of the joist.

Also if you have rigid ducts or pipes you may need to put these in as you go.

I have had similar with a plumber whose GAS SAFE expired but luckily I had another plumber who was willing to do all the commissioning. Like @ProDave said, just focus on the bits essential for FIT and I doubt that means BC completion cert for the whole job. If you need the EPC you will need an air test, so doors and windows need to be in. Good luck and sorry these idiots let you down.

I don't quite get it. It looks like the screws are going through the back of the hanger. Also you would probably need to screw through the chords into the block first so it is set the right distance. Fairly odd but I am sure they know what they are doing.

The chords on your joists are nice and wide and the joists tend to be much straighter than normal timber, so boarding and flooring is much simpler and you are not having to screw too close to the board edge or at an angle.

We have some timber end pieces on a river wall and they were countersunk to over half way.

not if is 20mm on a 47mm timber.