G and J

That looks rather brilliant. Well done.

Goodness. So the moral is…. decide what you want before you start. We are mulling over making a change to our design so methinks I’m going to call the nice peeps at CIL tomorrow for some guidance.

Ummm, that is unexpected, not heard of that at all. The CIL guys are interested in the square meterage that will be created (less maybe existing and recently used square meterage) but they seem to just accept the approved plans. You are worrying me now - where have you seen this scenario in action?

Except I’ll not have a dc connection to the battery.

That looks fab. I like Victron stuff, have used such in our vans and have great respect for it. Will research…. But in the face of it that Victron unit will fit perfectly in my scheme!

Thank you. Rather than fire tons of questions at you I’m going to try and work out as much of that as I can first. Then I’m going to fire tons of questions at you, but at least I’ll have tried lol

A word of caution, that’s the stuff from our local authority, but other authorities may have different interpretations. I suspect the guys at the CIL office are a bit like the guys at HMRC, in that they are used to being moaned at and despised. But call them with a smile, and honestly and openly seek their guidance, and they turn out to be lovely and helpful people. So why not call em and make friends?

[WARNING - DUMB QUESTION ALERT!] As I understand it, a passive slab foundation is basically a big lump of concrete cast inside a polystyrene tray. I think such can have a good u value as the polystyrene can be nice and thick, and thick edges to the tray help reduce cold bridging at the bottom corners. I suspect they are also effective for a passive house due to the simple large size of said slab. We haven’t got room for the tray and we probably haven’t got the budget, but I can’t see why I can’t get close to the key attributes with a strip foundation, beam and block floor, and enough insulation in the right places. Have I missed something fundamental?

I agree with that. There appears to be no downside to telling CIL that you are starting, even if it’s long before you are starting in any real sense. We consulted our local CIL team to ask and they were wonderfully helpful. They sent us this extract but they also pointed out that it’s ok to tell immediately us we are starting just to make sure we’ve done it before actually starting. “…commencement of the development is one of the following: (a)any work of construction in the course of the erection of a building; (aa)any work of demolition of a building; (b)the digging of a trench which is to contain the foundations, or part of the foundations, of a building; (c)the laying of any underground main or pipe to the foundations, or part of the foundations, of a building or to any such trench as is mentioned in paragraph (b); (d)any operation in the course of laying out or constructing a road or part of a road; (e)any change in the use of any land which constitutes material development. Some gardening and clearance works will not necessarily constitute commencement, but you can submit your commencement notice in relation to those works for the purposes of CIL.”

Ah, ours aren’t. I got the impression that there are passive house consultants who do their bit (design audits/certification/etc) alongside an architect and I’m thinking about having a chat with one. I strongly suspect passive house certification is not financially sensible for us but I’m also working on the assumption that passivehouse design thinking may be partly applicable and may improve our design, so I’m keen to explore that. Is anyone on here working with such a consultant?

You star. 🙂

That made me laugh. I’d still love to understand your system at a very detailed level, mind, but it still made me laugh.

Ta. That’s helped me get my thinking straight. We will be putting solar PV in day one but batteries only once we are sure we can afford them which depends on how the total spend goes. Our lecky meter will be in our attached garage and so I’m intending to bring the ac from the solar inverter back to the garage to a cross connection point where I can insert a battery unit thingy like you have but at a later date. I’m also planning to have two CUs, each separately fed from the cross connection point, one to feed lights, MVHR, router, Wi-Fi and freezer, which can then be battery backed up, and the other for everything else. My thinking is that the extra cable and second CU is a small short term cost to allow for easy installation of a decent sized battery system in the garage when prices drop and funds allow.

To check my understanding, your summer/winter switch determines if you are in mode “1. During cooling…” or mode “2. During heating…”. I’m guessing automating that switch would require logic beyond thermostats. Do you have a schematic/written description of the settings in case someone else needs to fix a fault with the system? (If you do guess who wants a copy!)

WOO HOO! I got it right. I think I’m starting to get there! If it wasn’t so late I’d crack open a cream soda to celebrate!

Fab. I’ll plug that into Jeremy’s spreadsheet.

So, if I’ve understood that correctly, the Victron inverter & battery can run the whole house if the grid is disconnected, and unless the bypass is activated, grid power comes through the Victron. Your main CU only connects directly to either the grid or the Victron. The west roof inverter however connects to the CU in parallel with either the Victron or the grid, depending on the bypass, which I think means your west roof kit is connected as @Pollock73’s schematics.

I think I know the answer to this but as I’m not sure I’ll wait for others who do know to answer.

Please could you show me a simple diagram of that. I thought I understood how our Solar PV would connect but I’m clearly missing something.

Ta. Appreciate it.

So I am building a Passivehouse - brilliant!

Play nicely ewe lot or aisle take yaw nail gun away.

Wren kitchens have that too. It’s brilliant.

To @CalvinHobbes The utility room will, I presume intentionally, function as an airlock and a boot room. Yes it’s a use of space but if that’s valuable to you and you are happy with the resultant layout then that’s cool. It’s always a brave move asking for a critique of your design, but don’t take it to heart.

Have you engaged a PH consultant?