Alexphd1

My raft was DIY so was just material cost so hard to say. A quick calc you would need approx 600m of pipe approx £400 maybe less if you shop around.

There is very little extra cost in running UFH pipes in to a insulated raft foundation. Even if you don't use them it's not a major. Gives you a second heating and cooling option at a later date.

We used stainless for valleys and soakers. DIY from ofcuts from roof.

I need to run the pipes from the unit out to the soffits. I have 160mm female EPS connections. Options are to reduce to 150mm and use plastic or galv metal or use the expensive pre insulated 160mm EPS pipe (verplas) . Any pros or cons in each pipe material . I am spraying open cell insulation afterwards so non insulated pipe is not a major disadvantage. This is a diy system with the mvhr units bought cheap from fleebay.

I have tried speaking to a few companies for design and supply of a system minus the mvhr unit. As soon as I mention I will not be buying a mvhr unit I never hear from them again, I would have been happy to pay a small premium for their service and I told them this, their loss! It going to be the basic flow calculations I may struggle in so I may be asking some simple questions shortly!

Yeah we have made many mistakes with Nudara but will probably use it again on the 2nd build!

You could put up the ICF with no Windows or doors, pour the concrete then cut out openings with one of those concrete chainsaws.... TBH I dont see what you will gain apart from bracing lintels ! If you are serious about ICF get on to one of their training courses or get out and visit other builds, you learn more in half a morning on site esp a pour day than spending days scheming up ideas such as playing with toy icf blocks. Where exactly are you located, see if we can't find you a project to visit.

@Humpty Dumpty Much appreciated for your genuine feedback. I respect somebody coming in telling the good the bad and the ugly on a product more than this is the best thing since sliced bread !! I was initially sold on the quad lock but I done a lot of digging on American forums and had mixed review. In a perfect world the house would be designed to the exact block size but to cut the eps icf is not a big issue.

Excellent spot. Thank you.

Both tanks are a thermal store ie dhw runs through a coil in preheat then through the coil in main tank. Don't get any good for UFH direct from solar thermal but PV will help. A few people in Ireland tried various styles of large heat stores with varied poor results.

John https://www.mcdonaldwaterstorage.com/thermal-store-vs-unvented-cylinder

Will be interesting on how we get on, we have a 500l TS heated by ashp/pv plus a 500l TS preheat with thermal/log gasification . If preheat store temp rises above main tank then preheat starts to heat up main tank. We will get a good idea on how well solar thermal actually works. For what it's worth this a trial and error project, wouldn't think twice on major changes if doesn't work ie change tank to a sunamp or even sticking in a oil boiler. Our thermal controllers aren't wired in yet we but stuck a plug on the grundfos pumps yesterday for two hours. It raised the preheat tank from 8 to 20 degrees.

@Declan52 what are you heating your store with?

@scottishjohnIs that not a unvented cylinder?

57 degree for a normal tank for bacteria plus it's a thermal store water is heated on demand (like a combi boiler). Nick, is this correct??