MikeSharp01

That is some serious windage.... I bet the foundations are humungus.

Sound advice - it is out of your control to all intents and purposes, you will have to await the outcome and the time will be better spent not worrying about it.

Looks good too, are the units handless?

Yes - I was refering to the case when there is no registered owner with the LR as was/is the case with the footpath next to our build. If there is a registered owner that is not you a new strategy will be needed.

Yes this is the case. If it is not being used you can fence it off and wait 8 (might be 10 can't exactly recall) years, then you need to put an ad in the London gazzette, or local equivalent, and say that if nothing is heard from the rightful owner in 2 years you will assume it is your land. Then if nothing is heard it is yours and you can register it. First thing to do is put a watch on the portion of land at the land registry. This will trigger a message to you if anyone does a search / enquiry at LR covering the parcel in question. Beware that the local foot paths officer might drift by or, as was the case last week with our path, a local volenteer comes by with a clip board and notes any issues with the path. If the path has a number then this will trigger regular reviews of it. You should also look at local planning to see if any covenants have been placed on the path. In our case a small estate was built on the road behind ours and the footpath ran between two of the properties. As part of the planning the council made an order that the footpath should be a minimum of 6' wide.

Welcome to THE forum for self builders.

This is the essential point about low energy home design in that function, how good it is at keeping the energy requirements down, has to go hand in hand with form otherwise you get a house that wont have low energy as its primary functional focus beyond being a machine fir living in. As I have said above I was happy with our architects but I acted as the energy consultant and kept a model in PHPP for each design to ensure they were in the envelope and where not they adjusted the design. So in the end we worked up three designs all of which were in the energy ball park before we chose the final design.

I am sure the U value will be the same but its not the I-joist bridges we are dealing with its the 220x310 gluelam and KERTO ends that butt up to the sheathing in a number of places it is designed to deal with. Today we have found evidence of a solution, used elsewhere, that involves drilling / punching holes in the foils. Given all this is helpful speculation I have engaged a WuFi professional to work it through.

Yes the walls, well parts of them - I joists and sheathing, are up on the sole plate and that is seriously nailed down.

Thanks for this Jeremy. Sadly we need the kingspan on the outside to deal with the cold bridges created by the large timbers in the structure extending to just inside the osb sheathing in several places. I have now sought out a firm to do a proper wufi analysis to check this out once and for all.

Consider it blown off! I liked working with our architects as they basically did a good job where we needed it and listened to what we told them. There are a couple of well known challenges they have: Firstly they don't do money, well / if at all. There are reasons for this, but essentially they see their role as giving the clients a vision of what the architects have gleaned from discussions with the client rather than an outcome that can be achieved within budget which is usually elastic anyway. Secondly the construction world is even fuller with new ideas than the academic world so expecting any one person or practice to have a grasp of all the ideas that are out there ... - I guess its why GPs refer you on to specialist consultants. Thirdly, perhaps most importantly, they are fallible, so the expectation, though not theirs, is that any issues will be picked up by the next part of the processes - the builder. Mike

Take a look through some old YouTube episodes of the Addams Family and you will get some great gate ideas and how to dress the rest of the place so it looks like the family that lives there is really 'out there'.

Yes - sorry Peter - I was only there last week and we talked about the possible array, should have remembered.

On another wrinkle - I have been looking at these in roof systems but I am struggling to get the panels flush with our fibre cement (Thrutone) tiles, this is similar to the problems I am having getting a water tight design for the roof windows flush with the tiles.

Where do you have yours, or are you running on micro inverters?

Hmmm... this is turning into something of a nightmare, we have all the insulation on site although we don't yet have the membranes - was on my list for this week. Anyhow the RIBA product selector sheet indicates this: "Joints between boards will facilitate the passage of water vapour under normal conditions of temperature and humidity." It is this that I had hoped would do the job for us and mean that water vapour could escape faster than the internal VCL. As I have not yet procured the VCL I could switch to 'AirGuard smart' which according to its blurb "lower sd-value of 0.05m (=25MNs/g) and an upper sd-value of 30m (=150MNs/g) for its adaptable AVCL DuPont™ Airguard® Smart." and should push it through in winter conditions. Alternatively I could run a lawn pricker over the sheets to puncture the foils!

Have not used it yet so still a chance to play with the details I guess.

Well its fantastic - great, you must be riding the getting close wave now. Have you started to wonder what you will do with yourself when it is finally finished?

How does it grip the hole?

I think you can get little threaded inserts you can drill the quartz, carefully and with the correct drill, pop in the insert and the action of the screw expands the insert. Its a bit like a short rawplug but the ones I have used, albeit, 20+ years back, were metal. This is the sort of thing. http://www.npfasteners.com/composites/keep-nut.htm

We are using Fin Joists (FJI). these use cross laminated timber, thick plywood, for the flanges of the joists and OSB for the webs. This makes them dimensionally very stable and weight for weight (I won't use mass in case...) stronger / stiffer / able to span longer gaps.... We also have a large number of KERTO (CLT) beams as the major structural elements - Ridge beam etc. We went for engineered timber for a number of reasons: We liked the idea of using sustainable materials. We wanted as much of the frame to be as dimensionally stable as we could make - I hate the way wood straight from the tree is able to warp, swell, shrink etc. To my engineering mind I wanted to keep the structure simple and open which is easier using I beams than SIP panels. Cost was an issue but because I am the major source of labour on our build I wanted something I could manage without help and that suited my limited ability with the wet trades - Brick/Block laying in particular. Thermal performance and simple foundations as a deep and lightweight frame provides the ideal structure for a lot of insulation with limited cold bridging that can sit on a simple (relatively) passive slab. Although I am doing it myself we spoke to a number of TF assembly companies and they were all happy to work with the FJI joists & KERTO beams.

Does it have units then? Or A. is it mascerading as something else that got the units already or B. An amalgum of units (ie other concepts combined) that could be simplified to something else that has units or C. Is it just a non unitised concept used a simple hook on which to hang more complex thinking / discourse. I guess that, in the end, the words are the things that resonate with people as most people understand the ideas of Thermal and Mass, which they probably think of as 'a mass' rather than the fundamental unit 'mass'. This may be at the root of our comprehension problem as the actual unit mass of something tells you little, if anything, about its ability to store heat until you combine it with its heat capacity per unit mass. So one is forced back on the presumption that while thermal mass might be a useful idea in facilitating a focus / context for a problem it is probably not useful in providing calculated solutions in building physics.

Yes there is a reasobable explaination of this here http://www.greenspec.co.uk/building-design/thermal-mass/

Yes it should say VCL really - it was a thread yesterday that prompted me to check as I was merrily working away on the principle that the housewrap was on the outside I agree I think the architect got it wrong for some reason. I will drop him a note to check his thinking but it is on every section drawing in this form so his cad package, Archicad, just linked it through everywhere. No but there is a reason the PU is on the outside of the sheathing so as to ensure the cold bridges of the I Joists and the ends of things like (only) the ridge beams have insulation beyond them. You are right it seems a bit daft to have the permeability the wrong way around but I surmised that as long as the VCL is less permeable than the PU (Even though it is foil backed) and I don't foam the PU edges tight the water vapour will pass out of the structure.

Way back in 2016, during our design exercise, which you all helped with here: I thought the build up of the wall (inner to outer) was: 12.5mm Platerboard 35mm service void. Air tight barrier. 300mm I Joists filled with DRITHERM .032 insulation 12mm OSB (4) 40mm Kingspan K12 Tyvek UV breather membrain 25mm Verticle battens (Ventilated) 25mm Horizontal battens (Ventilated) Marley Internit Thrutone cement tiles. However I have now double checked the architects drawings, and those submitted to BC and the build up is now: 12.5mm Platerboard 35mm service void. Air tight barrier. 300mm I Joists filled with DRITHERM .032 insulation 12mm OSB (4) Tyvek UV breather membrain 40mm Kingspan K12 25mm Verticle battens (Ventilated) 25mm Horizontal battens (Ventilated) Marley Internit Thrutone cement tiles. You can see that the Breather and KingSpan have swapped places. Simple question, does this make any sense putting the breathe membrane before the PU Kingspan, which is foil faced, as I don't get how the vapour can get out of the breather if it is covered by foil faced PU, or am I worrying about nothing?