Mr Punter

Gas Safe plumber would be my answer.

Bear in mind that lots of EWI has been a disaster recently. Lots of mould, damp and ventilation issues, so this needs to be done meticulously, especially mixing EWI and IWI.

Try it on a small section.

Yes. Look up "Leaky Condo" and see the consequences of omitting a drained vented cavity on timber frame.

Dritherm 32 cavity slabs.

Can you space them at 300mm (4 bricks) vertically, staggered each side of the pier, 100mm in? That would give you about 6-8 ties.

I think you may find it tricky to do much as you will need to drill / hammer to get any ties in and this will disturb the brickwork further. Maybe helical ties would work?

I would replace any completely knackered bricks and coat the chimney with StormDry.

Agreed. Better is a render carrier board battened off the structure to leave minimum 25mm drained and vented cavity.

I think it may work well with either internal pir or insulated plasterboard, so move the 50mm celotex inside. It follows the rule of thumb of having the most insulating and vapour impermeable materials inboard.

+1. For a new dwelling a full plans submission is needed. Building notice is OK for small works only.

Looks OK to me. I would rather a load of mass concrete and some tile adhesive rather than a mortar bed as the clay may shrink and heave which could loosen the tiles, but it is built now. Maybe keep a few tiles in the garage in case? Some drainage through the wall would be good.

Learning by doing. You will ace this next time!

Have you got a section detail showing the foundation, slab, insulation, DPM, DPC, screed and FFL?

I think he is a Scot, so no words minced!

The way to work this roughly would be assume 20% of your heat losses are through the roof and assume your improvements could halve this, so take 10% of your annual heating bill of, say, £2,000 and with a 15 year payback this would allow capital expenditure of £3,000. This is the minimum BC would be looking at for part L improvements. They may allow you to make the improvements elsewhere if they are not possible in the room you are working on.

Have you applied for Building Regs and paid the fee? If not, don't bother.

You often will just need basic information for an Initial Notice, then they will do a plan check and come back with any queries. Main points are foundations, structure, fire safety and drainage.

They often set up tripods to set the levels. Is this 2 guys working and 1 shouting at them?

You might want to try Sticky Stuff Remover or similar.

A sparky might comment but I think the blue and brown wires need more protection - like trunking.

If you are renovating it is a decent opportunity to improve the energy efficiency of the building by increasing insulation. The minimum fallback is spend the amount of money that would be saved in 15 years on the improvements. You may be able to claim there is no practical way to improve the roof insulation that would provide such a payback. Hopefully your heating bills are low, and if so, happy days!

I have had Accoya replacement windows made for a house in a Conservation Area. Apparently very durable but time will tell. Painted finish. I have used Guttercrest for ali gutters, copings and fascias. Nice quality. If you are cladding the fascia with ali, they only need to be treated s/w.

From your description I cannot work out how much of the upper floor has insulation at sloping rafter level and how much is at ceiling joist level. The ceiling joist insulation is simple with extra loft roll. You may need to use loft legs if your are storing crap stuff up there. If you can insulate the sloping parts, so much the better. BC may take a fairly pragmatic approach, especially if you would need to trash ceilings etc.

With timber frame the airtight layer is often on the outside of the osb sheathing. There may also be a layer of polythene vcl just behind the plasterboard. The cold air normally gets in via service holes not properly sealed. This is often extract holes, boiler flues, condense and other pipes. If you can get to these with a can of foam it may help. With the sockets you could use some of the child safety plugs.