MikeSharp01

Looks like the P8 problem can come from various sources. In this document https://ohmenergy.co.uk/heat-pumps/ecodan-fault-codes/ it mentions flow rate as the problem, maybe your pump is failing. Has it ever worked properly?

IS the heat pump running all the time, when it works, or are these the immersion units? Assume it is immersion units - which means your HP is not working correctly at all as I see it.

What you have looks good, you need to give them enough so that they can get it right first time rather than change things when they find out that your openings are not what they assumed in terms of build up. So other things to think about including are: Making sure the quote contains the Uw values for every window - you need to meet PH standard there. Specifying if the installer is responsible for attaching air tight membrane tape and / or connecting to the airtight layer adjacent to the window. Which windows are designated escape windows, if any. Which door(s) is(are) your accessible door(s) for BC purposes. If you have section drawings of your openings that will help them, and stop them coming back and upping the quote when they find a difficult opening. Including / not including such things as compriband on the external connection to the opening. Which foam to use when sealing around the windows - You can say a brand and /or say it should have similar properties to a brand. The finished colour(s) inside and out (Some colours are standard others cost), also if coastal location you will need a marine grade finish. Do you want secured by design as standard on all doors / windows on GF - this affects the glass build up and the locking. If you are expecting the windows to be installed with access to both sides. IE will they work from the inside or both sides. (On ours the windows are bigger in their boxes than the surrounding tile hanging so they need to go in from the inside although you can work on the outside.) Section drawings will show this to them. What is access like to the the site - can they get a lorry close and / or a window robot around all sides. Is there / will there be scaffolding - window robot then no good. Hope that helps.

Welcome to THE forum for people like us. Are you getting it architected, getting a contractor or thinking of doing it all yourself?

You can usually work out what you need and order it, if you buy quality it won't be wasted.

In my experience: Spax are excellent. UltiMate / Ultimate II are very good. Reisser are good. The 'Tite' range from screwys, I have found the exterior 'tite' to be excellent but a bit expensive (although not as expensive as Spax!) Timco are great for general work where tolerances, of all sorts, are sacker, their range is good and you can buy them in vast bulk and not feel the pinch too much. After that the world is your oyster. The thing that bugs me about most of them is the 'real' diameter measure. To me a 4mm screw should drop through a 4mm hole but they generally don't so you can get jacking if you are not very careful and get the hold size just right. Too big and the head sinks in a mile, too small and the joint is not pulled up as tight as you would want. I now keep drills 0.2, 0.4, 0.5 bigger than the screw spec to be sure I have the right size for every screw.

Great stuff this, wonder if there is one or more of these machines in the UK - anybody know?

After each visit you should get a report that sets out the work seen and the approval to move forward - they will have photos taken at the visits at the very least so as long as you have evidence of a visit and such followup you should be OK. The verbal approval is possibly more tricky but again you presumably have evidence you sent the photos (emails etc) and they have no evidence that they disapproved it following the photos / email.

Welcome to THE forum for people like us! £2.5K per m2 seems not an unreasonable figure for a mid range finish in your part of the world, so it should only go up a lot if you are going for a high end finish or you have some difficult features. Its a kit after all. How have you structured the contract - do they purchase the kit or do you do that direct and they set it up?

It seems to me that we would all do well to recall the old corollary to the addage "if you can't measure it you can't control it" which is "Just because you can measure it it does not mean you can control it." We have a passive stack plan, alongside full MVHR, for our build high level roof lights and low (ground level) windows. Although they are electrically actuated and we have sensors, all sorts everywhere, I have no idea how to control it other than bang bang control until I see the data.

Either way use stainless steel screws.

If it's a decent 10mm soffit you can use self tapping screws so a very small hole, shallow, is needed just to start the screw and select the length so it does not come through. You need not worry as if there is water up there you have much bigger problems.

Or just put a few controllable holes in before the test so you won't get a three and control it down to 3.2 on the day so you can still get a good SAP / whatever passes fro SAP. Hang on, just wondering if this is the reason some of the big house builders just don't bother too much with air tightness.

Now there is a thought - but I guess the powers that be are getting more famous for not thinking things through than they used to be.

Most modern cameras weigh nothing so the soffit will support one of them no problem

That's now rolled up into AI who knew that a 16th century technology would be key to your smart phone's face identification system!

I have been struggling with this whole debacle over the last 48 hrs. I have had a response from our BC who just reiterates the Part K stuff really but also does confirm that: Providing a restrictor, such as the one illustrated above, and safety glazing is provided he will be happy - in which cases we do not need to move the transoms up. The fall protection IS needed, in our case the restrictor and safety glazing, on the GF as the BC cannot be sure how the external landscaping might be finished. The glass in the windows must meet the requirements of BS6206 or EN12150 and be marked and certificated as such. (He did not set a kN lower limit - just BS6206) Laminated glass is required in all doors and windows on the GF for security purposes. So we have crossed off all the issues - talk about stressful! Thanks for all the help.

Somewhat down beat way to start the week, but hey, food for thought and you are correct, every day is a school day - thanks Gus.

Does that window open - at all / outwards and what is the soffit made of UPVC / Wood?

I know the great JS Harris, formally of this parish, tried to get everything to 1/10th of a deg and his hysteresis down to less than 1 degree but never quite managed it. I have this idea that a bit of AI from all the inputs, including sun / weather forecast should help close the gap a little. I guess this depends on what the plan is. I though a bit of research would be fun so I put the sensors in the floor, about 2m in front of each south facing window, we only have north & south windows of any size really, so I could sense when the solar gain was happening, as @joth points out - will also know if the blinds are open or shut, and allow me to get ahead of the cooling in summer and in winter / shoulder months manage the blinds / pump the water from south to the northern loops to even out the temperature and spread the heat around a bit / use the northern loops to cool the southern loops etc. We have 43 tons of concrete in our slab so it's good chunk of store. I appreciate there are issues, after all it's heat in the building no matter where it is, and that it's just a hypothesis but it will be fun to play with when its up and running.

You are correct but sadly I am just like that.

So does that mean that if the window is an escape window then the min 800mm does not apply - I just need a restrictor? In which case all my windows are fine as they are all designated escape windows 1 on the ground floor - window 1 in the snug and the others on the first floor in bedrooms!

This is great stuff. On the safety glass is mainly 4tuf, 4tuf, 6.2lam from inside out but some has the 6.2 on the inside. That was down to the window company - never questioned it. I will dig out some sections.

Not yet as we are not finished but I have one at the most risky place - top of north east wall, according to the WuFi analysis we did, so I might then start to worry.

I find they do need calibrating so I use a 5w Calorimeter and a traceable thermometer, put a few of them in at low temp 0 or thereabouts, and then let it track up, they can be several 10ths out so I mark the units and programme the curve fit, usually close to straight - y=mx+c, into the microcontroller - works a treat.