NSS

Welcome, and make sure you sort out CIL liability/exemption before doing ANY work on site!

Depends how fresh (clean) the air is outside your window.

Why would you switch it off. We run ours 24/7/365 but in summer the fanspeed is set to 1 (slowest) in the daytime and 3 (fastest other than boost) at night. We do use active cooling (via UFH) when particularly warm weather for several consecutive days. That said we have SageGlass which significantly reduces the solar heat gain in the house.

Sounds idyllic, and I'm sure it will be worth all the effort (and hassle). Looking forward to seeing more pics as you progress.

Okay, but whatever you do don't tell them your name, Pike ?

Now that looks to be both an interesting and challenging plot! Is it as secluded as it appears to be? Love how the design and overhangs step with the terrain ?

One additional thought. You say it had been on the market for years before you bought it, and that the conservation officer thought it was listed with higher protection than perhaps is warranted. I therefore wonder whether they would consider delisting it? Faced with the choice between it eventually falling down, or a refurbishment that was sympathetic to the original building but requiring a less demanding treatment may be preferable to the local authority - and significantly less expensive for you.

Then I have to be honest and say I'd be inclined to walk away, sell it for whatever you can get for it and swallow the loss. However, it sounds as though you're determined to find a way through this so my suggestion would be to turn the stable into your temporary home, even if that means spending a few grand that you feel would be better spent on the main house. It doesn't need to be fancy, just safe, dry and warm enough that your health doesn't suffer again this winter, with a loo, shower and basic cooking facilities. You'll need somewhere to stay while the dry rot work is done anyway, and even once that is done there'll be a lot of work (and cost) to get the main house livable.

Welcome @Imogen Some good advice and ideas already given, but when you say it's a "large" house, just how big is it (square feet/square metres)? And what level of "listing" does it have? Also, is it two-storey or three? Is there a basement? Is any of it on a single level and, if so, how much of it and what rooms are in the single-storey section?

Only time I've heard PAN in relation to building (other than the WC pan) is 'Planning Advice Note'.

I think if it was me and I could afford to, I'd buy the plot and build the "2nd" house first, live in it for three years (so as to comply with CIL exemption) and build the home you really want on the best bit of the plot (by mortgaging the other one if necessary), then move into that and sell the first built. I know, it sounds simple but...

Fascinating read and I have huge admiration for anyone choosing to build and live off grid. Not sure I could cope without all the creature comforts afforded by electricity on demand.

Welcome @TomBee and all the best with what sounds like an ambitious project. Ref @Conor's comment about not pushing for PH certification "as it doesn't add value", I wonder whether this will change in time? If so, and my guess is it will, if you're self-building now with the intention of living in the property for some years, and building to PH levels, then spending a few £k extra on certification seems like a no brainer. After all, if you decide to sell it in 5 or 10 years time, and PH is still seen as a bit barrier to potential sale, then you just don't market it as such.

Not the issue. We simply can't have anyone here because of shielding.

No idea yet. I haven't gone as far as getting a quote as can't have anyone round before the end of July (at least).

Apparently my SolarEdge inverter can fairly simply be converted to a StorEdge inverter that will (with LG Chem batteries) enable backup.

Hi @kaish, and welcome. Unusual for nobody to have replied sooner but you may get a better response to your question if you add a photo showing the current set up so people can better understand and advise what may be possible.

But I guess you'd need a lot of storage (and generation) capacity to go off-grid in anything approaching a typical household with all the appliances, gadgets, heating and lighting requirements. All I'm looking for is sufficient storage to power the ASHP for a few hours overnight and/or the MVHR, dishwasher and washing machine, and to provide power for the fridge, freezer, a couple of led lights and (if required) a nebuliser in the event of a power outage.

Nail on head. Sure, cost is a big consideration (and running the ASHP overnight is definitely of potential benefit in that respect), but the environment and at least a degree of grid backup are also important factors to us. We'll definitely add battery storage at some point, it's just a case of waiting for the cost to drop to a level we can live with.

Ah, not quite what I thought you were suggesting.

That sounds close to tempting. Do you mind me asking what/whose kit it involves, please?

Which is all well and good if, as you have Dave, done all the work yourself or if you've personally overseen it all. My point is that's not the case with a lot of 'self builders'.

Depends on how hands on you've been. Remember, not every self-build is self built.

But how do you know it's going to be little if you don't do a test when the house is complete? And it may not just be additional energy costs, it could affect the air quality provided by the MVHR (which was critical in our case). Also, in the context of the OP's situation, failure to meet the required ACH rate for passivhaus may not just mean losing the certification goal but needing heating where none may have been provided.

I wasn't talking about big developers (sure we all know they're results will be 'questionable') but self-builders. What's the point in kidding yourself that your house is more air-tight and hence more energy-efficient when it's you that will be paying the bills?