PeterW

If you don't want the G3 hassle then you go the thermal store way to get mains pressure hot water but an ASHP will not get a thermal store hot enough.

ASHP in this instance has all the wet connections in the house so I can’t see how it’s losing pressure without it being visible. Only place I would do a bog roll test is the over pressure valves and put a sheet of clean dry loo roll over the end of the discharge into the tun dish to see if there is an over pressure leak Did they fit a new hot water tank too ..?

It is commissioning date and you also need an as built EPC to claim RHI. TBH once the schemes close it will be like solar panels when FIT was 42p and the system cost £12k. Same systems installed these days can be change of £5k. Any of the “green” initiatives will go this way and you will find prices falling early next year.

You can self install an ASHP. By the time you’ve added up boiler, oil tank etc you will be borderline the same price as a mid range ASHP before installation. RHI just inflates the install costs as others have said. I’ve seen £3500 ASHP listed as £7995 “installed” and it’s a 2 day job - or £2000/day to the installer !!

But that’s irrelevant - fire escape windows don’t need to consider that element.

1100 is measured from the cill to the internal floor vertically.

Ok I’m not seeing the issue ..? Are you saying you need 4 steps in the same place as the square is on your plan ..? And what has the newel got to do with it ..? You measure the stair clearance from the centre line of the stairs as though there is a straight line drawn down the treads, minimum height is measured above that.

I use full bore valves and get them from JTM

only reason I say copper is that it is is straight and remains rigid. Also it is unaffected by foam unlike some plastics. I would connect the ASHP to the copper tails with 900mm full bore flexi hoses which should remove or dampen any vibration.

28 or 22 is fine - may have an issue finding a TMV at 28mm for a decent price and most UVCs are input / output at 22mm so 28mm may be irrelevant.

Made my own with 22mm / 15mm copper all soldered then added 15mm Hep2O isolators.

Drill an oversize hole with 10-15mm all round. Wrap a length of 22/28mm copper pipe long enough to do the wall plus a fitting either end with duct tape and centre it in the hole - wedge with some offcuts of armaflex then use expanding foam to fix it in place from both sides. Trim the foam flush and the tape the pipe to the OSB and then insulate as normal.

Felt would be a last resort as it doesn’t last. EDPM should be the next choice after GRP. Has the contractor who suggested the Sika product laid it on a wood substrate before as a quick look and it seems to be used more on concrete decks, and the prep for a wood substrate seems quite detailed with carrier layers bonded to the wood etc. Would be good to see some examples where they have done it previously

Regs are simple : If the floor area of the building is between 15 square metres and 30 square metres, you will not normally be required to apply for building regulations approval providing that the building contains NO sleeping accommodation and is either at least one metre from any boundary or it is constructed substantially of non-combustible materials. So you don’t need building regs if you keep it 1m away, neither do you if you use Cedral or another non combustible material. Sounds like a bit of careful planning of layout and you could actually not need regs at all.

Just as an advisory to those who do go manifold for the ease of isolating individual circuits - always cap the open end of the pipe at the point at which you terminate it, you will at some point turn the wrong isolator ......

@Thorfun Can run a 22 or 28mm supply to the plant room and then into the UVC Control block, taking the cold off as a balanced cold supply. From there you go to the hot and cold manifolds and then off in 15 or 10mm pipe to each outlet. You can run a standard loop from the balanced cold and the UVC hot with 22mm and tee off to each location with 15mm which is how it used to be done. Nothing wrong with that, you just end up isolating at point of use rather than supply.

Is this £700 from a BM or £700 online ..?? Some of the online ones give a volume discount. Drainage Sales online do decent pricing too Just checked and they offer 7.5% discount on over £750 so worth checking if you can up the spend as the extra £50 would be covered by the discount. https://www.drainagepipe.co.uk/110mm-drainage-c-20/

@newhome you just need a BFO ASHP now and that will halve the heating bill too !!

What’s the finished surface going over it ..?

Got those photos yet ..?

Is that why Samsung has a larger market share of mobile than Apple then ..?

Toilets tend to have built in isolators so I just run direct to them.

Finished floor surface @Jilly ..? Could always float an engineered timber floor over the top of battens with a pug mix between so you could get away with 120mm of insulation with 15mm pipe and then 18mm flooring

At about £100-150 a truss, it is simpler to do it now and take the hit but have a design that works. You can then box in or infill with timber on site until you decide you need it. Don’t forget that any roof window needs to be below 1100mm cill if it’s to be used for escape purposes.

Isn’t that a bit dangerous as it means your external sump is linked to your internal sump, so if the external floods then the internal will flood to the same level...??