Crofter

I think it's hard to persuade the general public that burning wood is bad, in the same way that it's hard to convince people that eating bacon is bad. If humans have been doing something forever, surely it can't be that bad? Unlike those newfangled heat pumps and EVs which are clearly not to be trusted.

Hard to tell from the pictures but it could be something like sarking boards with 20mm chips. You'd want a membrane underneath to prevent weeds from growing through. And ideally you'd be laying the whole lot over a good firm surface, like type 1. You can bed the boards in to type 1, packed down in little trenches.

How is V2G fundamentally different to home batteries?

My MVHR grilles are in the soffits, seems to work well but I can't remember where I got the parts from. Likely the same place as the ducting.

Obviously it won't work for everybody. But we're talking about emergency situation. If it's a wide area power cut, most people won't be going out to work. If it's localised, surely you can call a friend for a lift? Most EVs have five times the battery capacity of a house, and it's only needed a few times a month, or less, for longer journeys. It seems completely sensible to tap in to that capacity.

Is the power cuts thing a bit overblown? We live on the Isle of Skye, which has no installed backup generation and relies entirely on the power lines from the mainland and, to a limited extent, the connector from the outer isles (who have a diesel power station, but not really big enough to export). In the 12yrs we've lived here, the worst power cut we've had lasted 37hrs. I can't remember any other power cuts lasting more than ~12hrs. During the 37hr power cut, I remember being a lot more concerned that I was about to lose hundreds of pounds worth of frozen food (we do a big shop in Inverness every couple of months) than I was about getting a bit cold. Curious to see what other rural areas are like?

I'd have preferred to see a middle ground where a small wood burner was still allowed to provide backup heating in remote areas at risk of power cuts. You could achieve similar redundancy by mandating substantial battery storage, but that gets pricey. I'd like to think that a house built to proper levels of airtightness and insulation, with a correctly specced and installed heat pump, will be so warm and comfortable that most people would quickly get over the novelty of lighting their stove anyway.

I'm not sure this method works with tar planings? There's not really a surface there to cut. It's still a somewhat loose material, basically small stones that are slightly stuck together. Like a big bowl of sticky rice.

Perhaps that's why my A2A has some sort of fancy nanoscale filtration system, that supposedly cleans the air as it passes through? I thought it was just marketing guff.

Yes, it takes in air from inside the house and warms it slightly. Way more efficient than pulling air from outside and having to heat it up all the way. What health concerns?

The driveway to our cottage is fairly steep with a tight turn. We initially laid it with type 1 which rapidly began to form ruts and potholes, as soon as the rain had washed away the fines. I laid a load of tar planings over the top and packed it down with a walk-behind roller. What a transformation! It basically became as good as a tar surface but under a third of the cost. It's not been 100% perfect though. There is one spot where repeated vehicles have managed to scrub a hole through the surface. The cottage is a holiday let so we have had hundreds of people going up and down, and they tend to be a bit hesitant about the steep, tight turn. If you know what you're doing, you know not to take your foot off until you reach the top. I have had a half hearted attempt to repair the pothole, using some loose planings from the bottom of the drive, and mixing in some bitumen. It was extremely messy and without use of any heat the bitumen remained a sticky mess just under the loose chips. I think over time it will set, but it's taking much longer than I expected.

In mine, you can set it between 17⁰-24⁰C. On the lower settings in particular you can't really tell that the air is any warmer than ambient. But due to the volume of air flow it does very quickly heat up the room. I was actually worried that something was wrong when I first installed it, because I expected the air to feel much hotter coming out of the vent.

What do you think the COP of A2A is? Some units I was looking at were around 5.5. By the way, I've recently completed the installation of a Panasonic system. The clever bits were done by an f-gas engineer, then I finished it off myself. Because I had several rooms to heat, I chose a ducted system. We installed it under the floor and I ran the 200mm ducts to grilles just above skirting height. Early days but so far I'm delighted. The response speed is amazing. You only notice a draught if you stand right next to a grille. The noise is definitely detectable, although any background noise whatsoever will drown it out. Total installation cost was £4200, no grants.

For context, the first house I built was 43m² internal, and the possible next one would be similar but with a second bedroom. I'm not sure if splitting such a small house over two floors works...

For a house, you don't just want maximum volume, you want to divide it up into 2.4m high sections. And you have to work around the pitch of the roof. I think the maths would be beyond me, but I have every faith in your abilities... go on, you know you want to!

Yes, room in roof is an obvious stepping stone- it seems almost daft not to do it. I'm pondering another small build, slightly bigger than the first, and likely going down a conventional build route rather than portable. But I'm not sure if I'll end up going for any sort of an upstairs. Not ruling anything out at this stage.

It's well known that to minimise cost/m², building over two stories can work well. You sacrifice some space to fit in the stairs, but your expensive roof and foundations are now serving twice the floor area. Is there a rough rule of thumb for how large a house has to be before these savings kick in?

I don't think I'd bother with a wood burner next time. I'm also not convinced that the extra cost of aluclad timber windows was really worth it. They look pretty nice but they've not been trouble free. The uPVC I fitted to the other house have been much easier to work and live with, and a third of the cost.

Sorry to hear about your health problems. Are you able to live in a place after deep cleaning, and/or with sufficient medication? It sounds a nightmare. If it's really not possible to mitigate the effects, you'd think it should be treated with the same priority that disabilities are. Just to play devil's advocate, some people rely on their pets for their mental health, and it's pretty heartbreaking to hear about vulnerable people having to give up an animal which might be the only thing they can trust. Happens when homeless people are housed.

Is it possible to avoid having a joint there at all?

Oh and if it's of interest, I've chosen an underfloor ducted system. Just installing the final duct just now. I have three rooms hooked up already and I'm really impressed with the response time. Running costs look like they should be good. There is a certain level of noise but you only notice it if there's zero other background noise.

I'm just finishing off the DIY bits of an A2A installation. It was supplied and partially installed by a guy based in Lockerbie, he was really helpful and easy to deal with. He might be a good point of contact for you. Message me and I'll put you in touch (and no I'm not on commission etc).

This looks pretty solid... https://toughleads.co.uk/products/hard-wired-heavy-duty-wi-fi-control-switch-230-415v-16a-32a-options?srsltid=AfmBOorigu5GXrsM5hGImuOvIcbLVWK8kMHPFg3tDIg5VklB48iLiRQY

Well that would be one way of the oil industry working towards carbon neutral.

That's a great little house. Interesting that you chose steel for the frame. I did something similar but built mine on Douglas Fir beams, 150x300, with engineered timber joists to make a sort of ladder chassis.