PeterW

Only for supply and fit - there has to be an element of labour included for zero rating.

So for digging out a 60sqm floor and relaying it you’re being quoted £6k or thereabouts by my calculations … For a weeks work for 2 guys..?? I’m in the wrong job..! TBH you will get away with not needing a buffer tank here as the UFH in the slab will need a lot of heat off an ASHP - it will just bleed heat until you start to dry out the fabric and get to some sort of equilibrium. A standard monoblock heat pump needs nothing inside - only query would be about hot water ..? A2A isn’t that expensive either if you are going with a unit for upstairs and one for down but if you’re going full splits etc it can get pricey plus it needs more wiring and pipework than is first considered. Another option with this sort of building is a pellet range cooker - they give a constant low heat and can be surprisingly efficient if you have the space. They aren’t cheap but do qualify for some of the renewables grants https://www.stovesonline.co.uk/wood_burning_stoves/Klover-Traditional-Smart-120-wood-pellet-boiler-stove.html

Those numbers are bonkers unless this is a 250sqm ground floor cottage !! How many rooms etc do you have ..? Floor plan would be helpful.

@Jilly how big are the rooms as I can’t see any dimensions .? And where is the manifold ..?

Its rubbish !! Radiant foil insulation needs airspace and this doesn’t have any barring the tiny amounts of foam between the layers. Thats horse$hit too as they both use aluminum spreader plates - the Wunda foil version is the top surface of their overlay system. Both work the same way and need fibre insulation up behind them to keep the plates against the floor surface. Also worth considering what the floor finish will be as that affects heat output / spacing etc. If not going ASHP you will need a buffer tank and you will need blenders and pumps on all manifolds.

No idea where you’ve got that from - the Wilo Yonos is 17-20W max. That’s £10 per year based on 36p/kWh and 8 hrs day/180 days per year. Your average TV on standby uses about 4 times that…

It will add zero value as it needs airspace to work and even then is poor. Do not do it. Is that installed ..?? If not … it’s nuts !!

Wilo for me - they are near silent.

beware of using sliding doors - they are difficult to sound proof.

25mm EPS, DPM, 200mm EPS, ~ 95mm concrete, topped with SLC.

Ok I would go back and confirm with them as they are normally pretty good and this may just be an oversight.

He is correct. You may find the Arotherm internal pump isn’t as powerful as the old GSHP pump so you’re getting less flow through the system and consequently less heat to zones. That looks like a fairly old JG system so retrofitting a pump and blender to it would be a challenge however it does make it easy to modify and fit a new manifold and blender / pump set. As @ProDave says too - whilst it is all off, get the loops flushed properly as they look full of crud ..! I take it there is no mag filter in the system anywhere ..??

Unusual as they normally have to be the full height of the joist to provide rotational support. Who has designed the floor ..??

@CalvinHobbesthere are better suppliers who are also cheaper so you’ve dodged a bullet there. BPC do a design / supply service and I think @Nickfromwales uses someone else too so there are plenty of decent options.

Why..?? Have a look at the Sky Glass ones and they start at 42” and that’s a pretty decent TV ..! 55” is nuts unless you can sit about 20 feet away from it ..!

Seen the Wiska 206 boxes..? Come complete with the Wagos, pre-drilled for M20/1.5 and can also be fitted with a piranha type earth clamp as part of the box

Just looks like mortar infil to me - the arch is doing all the work there by the looks of it. If you’re handy with a grinder and have a decent scaffold to work from then you could helibar it yourself using one of the kits - it’s basically 30mm deep cuts with 6mm twist bars and then epoxy grout inserted into the cracks. That will stop it moving any more and you can always drill and inject epoxy mortar into the crack too.

I would go secret gutter and cover over - with that low pitch I’d want all the joints as tight as possible.

BTW I wouldn’t count his videos as a decent source of info.. in one he says you don’t need mag filters in heating systems … which is interesting given it’s a manufacturer requirement to meet the warranty of one of the brands of boiler he fits …

No it’s a crap practise that causes more problems than it solves for the sake of £200 for a blender and pump. It gets even worse when the ASHP circulator is a PMW controlled one so the flow rates aren’t constant into the loops so balancing and setup is a complete #€%$£* of a job. The manifold pump and actuators are controlled by the wiring centre / thermostats that then in turn call the heat source.

You need to read 7.1 and section 7 as you are doing a conversion so the 5% rate refers not zero rated. Zero only applies to subcontractors when the full rate is exempted. you’re about as far away from the truth on CDM as it can get - CDM2015 is onerous to the n’th degree and is not just some paperwork. It starts with Principal Designer and works through from there - it’s one of the key benefits of not using VAT registered companies to do conversions and residential self builds. This is the start point : https://www.hse.gov.uk/construction/cdm/2015/index.htm For the whole of the construction phase you will require a Construction Phase Plan, and HSE may request it at any time.

So you’re liable for all the CDM elements that a domestic client can pass off - what insurances has the company got in place ..?? Don’t forget that the subs won’t be zero rating as you’re contracting as a VAT registered entity - it’s only the end client that gets the benefit of zero so your cash flow will be VAT inclusive.

It’s not going to be continual vibration and tbh you are more likely to get movement from thermal expansion than the stairs being used. Standard Talon clips with spacers will be fine.

So you are your own main contractor ..?? And if it’s not owning the building, are you planning on buying the finished build personally from the company at the end ..??

Limited Company ..?? Hope you’ve had good tax advice as that’s not ideal when it comes to single builds as there are other liabilities. No real benefit buying 110v if it’s a single build - you’re not going to get the resale value when you finish the build and sell them anyway