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Hi @joth, what A/C system did you go with? Thanks

Yes thanks @nod doing some more searching it seems that I will have to be responsible for HS as you only side step it if you have a fixed price contract with a main contractor who themselves will be paying sub contractors. I can't find anything to contradict this unfortunately.

I will be paying for in day rate.

Yes sorry I meant professional/trade insurance. I want to take out separate site insurance, but they recommend having some form of contract with the builders hence this post. I want to absolve myself from the HS responsibility and put it on them.

I ask the question because those 3 projects where in France. They will invoice me on lettered headed paper at the end of each month. They have all the correct personal liability insurance for themselves. Anyone?

I have some references already and everyone sings their praise for the skill and hard work ethic. My very good friend is a plaster who works with many builders and building companies in the area and he says they are the best and its who he would get to do his house. I trust him. Of course things may go astray for various reason, but I've done time and money on 3 projects so far without any really surprises or run away costs. If things start sliding I will simply stop working with them, it is a risk but I feel its the only way I will get the quality I want. Anyhow back to my question..

Hi, I've got a couple of guys who come very recommended to do my build on a pay per time setup. I want some form of contract which basically say they are the main contractor and therefore responsible for the health and safety , etc Is there anything like that out there? What have other member done? I'm also wanting to get site insurance and I suspect that will require something like this as well. Many thanks as always

So are you doing this all yourself (design) or do you have an A/C company helping? I cannot find anyone local yet who can help me on this. What system/software/box are you using to control air dampers (could you provide me a link to such an item as well please?) ? Any information I would really appreciate it. Thanks

Prices always vary through Brexit or no Brexit all for the reasons mention already, from currency movements to global markets, talking to a wood supplier a year or so ago the price of timber had increased in the previous 12 months due to the amount of storm damage that had been happening in the US. My main concern is not actually the price as thats generally always out of my control, but more the supply chain and the project constantly stalling due to lack of materials. My build is a timber build so this is a particular concern for me.

Well given whats happened today, I'm now planning to try and buy forward as much of my building materials before end of Oct. Its going to be error prone and could well cost me more. I've already lost my 20 years worth of pension contributions in France (if we do leave) and cannot face it prolonging my build (and increase cost) due to supply problems. My life is just too short and Brexit has already ruined my life enough. @Nickfromwales please close this thread.

How are you controlling the A/C temp? One supplier I spoke so said I'd really need separate controls in each room otherwise one or 2 rooms could get too cold, I said I wasn't too worried as the A/C was a course grained effort to bring the whole house temp down.

Yes makes sense indeed thanks. I suspect finding someone willing to commission/check it over as its just the installers who do this so can't see them being motivated. However I think I'll have to end up doing it, as the labour rate is just too crazy. If only I could do the same for the ASHP!!

hi @joth yes my mistake - I was looking at the efficiency ratio. Whats PHI?

Hi @dnb, Where would I find Approved document F please? I did read with interest your thread here and was looking at your design - is this the final one? It seems you are 'pushing' (for want of a better word) cooled air from the A/C into the hallway and then also the central plenum for distribution. The return to the A/C seems to be coming from the MVHR and the plenum - can you run the MVHR at the same time or will there be too much draw for the MVHR, or will the draw just be reversed from the plenum? My house is a simple single story design The central corridor will have a false ceiling whereby I'm planning to run all the MVHR ducts to the rooms. Im actually planning to put the MVHR in the garage and not the boot room as shown just to save some space.

So just to be clear : does the 'commissioning' need to be signed of by any 3rd party?

Thanks. How do you adjust the flow rates? Is this done in the plenums? Whats the difference between 'total background ventilation rate' vs ' total airflow in/out?

Ah let me know how you get on, I'm only just looking into this aspect - I need to find a local A/C supplier who is willing to work with me on this.

Thanks @JSHarris. What exactly is involved in the commissioning and balancing? Where could I go to find detailed information about this? I've have a further requirement that I want to install an A/C unit and reuse the same ducts if possible and there is no installers my part of the country who have any experience or can do it.

Hi, Probably a dumb question but can I install the MVHR rather than using an installer? I know building control want details of the MVHR being used but does that mean I need to use an official installer? I'm looking at a quote of £8,744 + VAT from the installer: 1 x Zehnder ComfoAir Q 350- MVHR unit 2 x ComfoWell Manifolds (including sound attenuators) Radial Pipework – Zehnder ComfoTube (smooth interior) 12 x Standard – Supply/Extract Lindab Airy Vents (round/metallic/white) 2 x External Wall Grilles Controllers – ComfoSense C67 remote display Labour & Commissioning From a rough online search the materials cost about £3000! unless I'm horribly mistaken but I don't think so. That leaves £5700 for the 'install and commissioning' Is there any reason I could not do it, or the builder for that matter?

Hi, I'm trying to compare quotes for MVHR and its like comparing apples with oranges it seems. Anyhow what level of efficiency should I be aiming at? The units I've got quotes for thus far range from 57% (NIBE) to 90% (Zehnder) The quote difference between these 2 installed is £3000 ! More info here: https://database.passivehouse.com/en/components/details/ventilation_small/nibe-ab-nibe-ers-20-250-1301vs03 https://database.passivehouse.com/en/components/details/ventilation_small/zehnder-group-nederland-bv-comfoair-q350-hrv-comfort-vent-q350-hrv-0956vs03 Any pointers most welcome

For you reference , here are 4 quotes I have so far for 160m2 house are (all with 200 L tanks): ASHP (NIBE 8kw) £13,873 including UFH ASHP (NIBE 12kw) £10,680, UTF £4294 with option for ASHP Stiebel-Eltron 7.5kw £11,768 ASHP (Pansonic Aquarea 12kw) £12,368 (no UFH quote) - in this they are quoting £3600 for the labour install which seems bonkers to me ASHP (Unknown!) £11,250 , UFH £4700 They are all expensive, but there are not many installers to choose from around here. 3 are MCS registered. 2 have given RHI year paybacks as ranging from £1200 to £1500 year.

Well the picture is different now compared to when I made that post 10 months ago. However clearing the pound has devalued quite significantly since the Brexit referendum result (was at ~1.4 /EURO now at ~1.1/EURO this alone as the biggest impact on the material costs. At that time Bank of England forecast paints a further picture of weakening pound agianst increase in trade barriers, weaker economy etc (see here) in no deal scenario. I have another post about this but duty on materials will add a further ~6% on average to cost. So these are my 'crazy conclusions' at that time. Much of this is a massive unknown and sentiment in the world market but I can only draw on things written from experts in their fields and not facebook, Guardian, or the Daily Hate.

I'm confused. There is import duty as well as the tarif + VAT?

Thanks for link. If I search wood I'm seeing 0% tarif (not sure if this link will work https://www.trade-tariff.service.gov.uk/headings/4407?currency=EUR&day=8&month=8&year=2019 ) Am I missing something? Bricks: 1.7% Ceramics: 2% Screws/Bolts/etc: 3.7% Plasterboard: 1.7% Insulation: 0% (I think) Aluminium windows: 6% Electrical cable copper: 5.2% Zinc roofing: 5% Glass sheets: 2% Cement: 1.7% Plastic piping: 6.5% Aluminium pipes: 7.5% Electrical sockets/fuses/etc: 2.3% Electrical storage heaters, cookers: 2.7% Brilliant.

Im about to embark of building my whole house. I'm very worried about Brexit WTO impact and supply problems. Some light googling suggest about 6% increase in materials but I'm not sure about windows /mhvr/asp/kitchen etc. I suspect when supply is limited it will drive up the price as well plus the weaker pound which is bound to happen. What can I do though, just wait several years or get on with life... Such a mess.