Dave Jones

your altering an existing home which is completely different to building once from scratch.

Correct as its not home insurance. Move into a building site at own risk!

more than likely it will be 75mm as this works brick to DPC. Personally prefer the dry screed over the wet crap any day of the week. Dont buy the hype its perfectly level. whats your issue with just cracking on with 75mm ?

i would bet you were not in fact covered and come a serious claim it would hit the fan. Home insurance needs a home which isn't created until a completion cert is issued. Prior to that its contract works insurance.

nice brickwork. tiny windows though ?

what did you pay for ? strip the whole lot off, new firring strips, new osb etc or just an overboard ? pay cheap pay twice.

replace the window for a wider/narrower one to give you some height ? Good example of an architect drawing being total crap when it comes to the reality of building.

cranked ceilings are a massive pain, if you remove the insulation at the corner to allow airflow you will have a cold spot and black mould. could allways fit a single room MVHR unit to take care of the humidity.

awful design to squeeze in 2 windows. lead would be my preferred osb under it. could use rubber also. would have looked soo much nicer if those roofs were joined.

you said air test pre-plasterboard ? Would be hard with ceilings open to trusses no ?

wont help unless the eaves insulation is removed though.

contractors all works when you commence. high 4 figures.

yes, you have blocked airflow at the eaves. It needs to freely flow under the tiles and exit the ridge.

that big gap under the roof trusses

£60k for 3 days work is a bit tasty. Have you had the foundation designed by an SE ?

they wont care means nothing to them. been there done that.

if the real QS is 700k then it will be loss taking into account he plot/clearance costs. Can see their point, they have to pick up the pieces if you fail and still cover themselves. What m2 cost are you at with your materials only budget ? less than 50% of reality i would guess.

no ceilings ?

sell whatever you need to sell to get it rendered. It's your external weatherproofing. Shame to ruin the rest of the build due to weather damage over the winter.

we have cooling with fancoils. dont go too mad and overcomplicate it. IF your insulation and air tightness is good, running the ASHP running at dew point +1c (15-18) 24 x 7 through the underfloor and fancoils at virtually no cost keeps the house perfect. Extreme cooling is only needed for short blasts where heat has been allowed to build up which is a design failure.

we have the separate neff downdraught in recirculation mode. MVHR plenum (has its own filter as well) is a few M away from the island as well. Works very well but not cheap.

back to the first step. Post up your heat loss calcs they have done and advise your house build type, level of insulation etc.

i would ditch the stone cill as it will chip and stain anyway. get a stub cill from the door company then you can run a slim slot ACO tight to it and slab tight as well. You end up with a small 10mm drainage groove which looks much better aesthetically.

nothing has come down that much, lots are going back up - insulation for example. Inflation.

another fantasist. Build cost using real trades and merchants are from £2k m2 for cheapest of cheap builds to £3k for legoland type finish. Obviously making parts of the build free will give you a false picture unless your work has no value.