Mr Punter

I saw a house we converted 20 years ago. We put in Ikea kitchens that we brought over from Holland (much cheaper at the time). Kitchen is still there! https://www.rightmove.co.uk/properties/87134338#/

Hmm I think I will just get indemnity insurance if lenders will accept. Is it fairly common for there to be no planning consent on converted flats? I checked others along the street online and could not see much.

I don't think Ground Source HP offer many advantages over Air Source. Air Source is far more widely used so will probably be a much better bet in terms of future availability and innovation. Heat pumps are zero carbon, subject to electricity generation method. LPG is a pain and I would not recommend. You are held to ransom by the suppliers. It is expensive and emits CO2. Solar thermal seems a waste of time compared with solar PV, which is getting better all the time. PV is zero carbon. Woodburner is toxic and polluting and expensive if you don't have a free supply of wood.

One for the architects / property pros... I have a building that was converted from a house into 8 flats at least 15 years ago and occupied as such since. There does not seem to be the correct planning consent, so I am considering applying for a Lawful Development Certificate. Any idea what fee I would need to pay for the application?

You are unlikely to get more than 70mm.

It is no only the heating bills but comfort from lack of draughts and annoyance that you have spent a lot of time and money for it to be slightly tainted by something so relatively easy to address at an earlier stage.

A bit cold for him to start today.

Well done for all your efforts. I think this suggests that it is worth having an air test after first fix, before plasterboarding.

That is good. We have fixed up into hollowcore planks and got about half a bucket of water from each core. I guess the ones we didn't drill still have this.

This sounds quite subjective. It may be worth looking at other successful schemes in the area and taking a cue from them. If you can find one-off houses, do some research and see who the architect is. Does the local plan give any positive clues?

That looks like high humidity. Have you got a hygrometer / humidity sensor? Try it in the office. Open the supply valve in there. In the bathroom is the extract vent directly above the shower? Does this only occur within an hour of bathing / showering?

Agree just fit some extra battens if the holes are wrong. Maybe these will be better hook fixed, as the existing holes are no good. As it is at the top you could add an extra layer of Tyvek locally, just to be sure.

With the blocks laid flat you gain nothing structurally or thermally. You have an extra £1,200 in materials and £2,000 in labour plus additional time. You also lose 9m2 of floor space, which at £3,000 per metre would be £27,000. Not the way I would chose to drop thirty grand!

The things that affect the deflection of the floor are about in order) joist span, joist depth, joist spacing and joist width. If the span is less than 3m, do whatever you like. More than 5m and the choices are limited. Do not accept the minimum allowable deflection, as it will feel crappy. Specify that you require maximum deflection of 8mm or 0.002 x span (whichever is least). That will always feel nice and solid. The decking does not make much difference to deflection. 22mm chipboard is standard and works fine.

The Posis make plumbing and wiring a lot quicker, especially if the joists have tight centres. No fun drilling solid joists at 400ctrs. You won't find the plumber and sparky charge any differently though!

Will it affect doors and skirtings?

Precast floor is unusual. Is it the hollowcore planks? They have a fair bow in them so you need batten on underside a levelling screed on top. Also, if you are having UFH at 1st floor you need insulation. Look up the Tony tray as used by @tonyshouse.

I suggest you get a quote for Hi-Therm lintels and if you go for them, make sure your SAP person includes the psi values in the calcs. They are not a stock item, so leave yourself a good lead time.

Does it have planning consent? Are mains services easily available? Are ground conditions stable? Underground or overhead obstructions? Reasonable access? Have you got the money to do this (budget £2,700 per m2 to be safe)? The rest should be done with your lawyer.

I don't think there will be a lot of benefit. Spray with glyphosate after April. Scrape the very top with the digger and pile it up for a later bonfire or compost heap.

Pavingexpert is a good resource for this sort of project.

Seriously has he considered a change of diet? An occasional upset is fair enough, but if this is a regular occurrence It may be worth thinking about his digestive system before trying to compensate with the ventilation system.

Unless you need some special performance spec I would go cheapest boards. For ceilings, 15mm can be simpler.

I can't see where the roof is on the bays. I don't think it would kill the elevation if you just had bays on the ground floor and probably would not make much difference to you, especially if they serve bedrooms. If the trees are deciduous the windows may cause some overlooking as current.

I suppose they could work it on total cost to construct divided by number of houses, so if you are looking to build the 55th house, they could charge 1/55 of the original cost and contribute the same proportion to ongoing maintenance. £5,000?