The build

Underfloor will be electric. We’re having 2Kw of solar panels as well. Mainly so we’d pass sap. You come across them? Don’t know if that’s just a Scottish thing. As all regs are different up here to England & Wales. Anyway it’s lots of box ticking to make your house as energy as efficiency as possible without being a passive house.

I believe the MVHR will take the outflow from cooker hood. It takes hot damp air from kitchen, utility & bathroom. And feeds fresh warm air into the bedroom & living rooms

Yes we have SAP down here but, ours isn't anywhere near as restrictive as yours. In England and Wales, the property is judged against an average dwelling when it comes to running costs. In Scotland it is assumed that the average dwelling already has some form of renewable energy, so you have much harder targets to reach. 

Now then, electric cabled underfloor heating system, they are super cheap to buy and install about a 5th of a wet system but, they are traditionally quite expensive to run. An average 100sqm home run for 4 hours a day would be about £110 a month for electricity with a cabled system but, underfloor heating systems are not generally designed to be switched off and on daily, they become much more effective when running permanently but at a lower temp, that way you remove the drafts like in a conventional house. However, if you run a cabled system like a wet system it generally works out more like £275 a month. That's assuming 1kwh is about 15p.

I'm not sure how you want to run your system but, your vaulted lounge is going to take some warming if the heating goes on and off throughout the day.

Sorry SC, this wasn't meant to be a downer.... 

Not a downer at all. The underground heating is used as background heat. We’ll be having secondary heatIng in living rooms & bedroom to boost as and when needed. Possibly inferred from  jigsaw solutions. Bob’s not 100% convinced. But he can shove the panel heaters he keeps rattling on about where the sun don’t shine   . As you can see not everything is written in stone already. 
Our first couple of house designs were done around us having a wood burning stove. But we scrapped it, when we realised that in 15/20 years time we’re not going to want and quite possibly be able to cut & split our own wood. Definitely can’t afford to buy in ready split. So we scraped it. Hence the ongoing discussions about heating.

I luurve my woodburner and even though it is quite expensive with bought in wood it is only lit as an extra to the central heating, to cheer me up on a dark and windy night!

Mikey/SC your discussions are so interesting. I've often yearned to build our own but never seriously, I don't think I could cope with the stress. Really interesting to see your thought processes around your decisions SC. Hope all progresses well.

The closest I've come to building my own house was turning a small, single storey, 3 room cottage into a 2 storey one. I wanted it to be as self-sufficient in energy as possible. An architect friend helped me to draw up the plans and, after a few hiccups, I was granted planning permission. My extreme "green" ideas cost me a fortune and I learnt lessons from doing it that, maybe I wouldn't do again. 
Solar panels on the roof were worth having although, as I didn't live there all the time, I didn't use all that was generated and it went into the grid. They generated only on sunshiny days which was usually when I would be outside not using power! Slow cookers helped to use a bit!. I think you can get batteries to store the surplus energy now and that would be good.

All the rainwater from the roof was stored in an underground tank. When full, it overflowed into the public drains. Each time a toilet was flushed, a pump would kick in to refill the water in the cistern - this was good and my water meter bills were very low. I could have added a hose pipe for watering the garden - but didn't bother. If the water level in the tank was too low, a float valve triggered mains water to top it up. It all worked fine until the pump jammed and kept pumping water out into the drains and drawing water in from the mains - for a week whilst the house was empty. Took me months to repay the water bill. 

I had 2 woodburners , one up and one downstairs but had to build chimneys in the roof for the smoke and vents in the walls for ventilation. 

It was an interesting experience but would think twice before doing it again. 
Your new build, with a blank canvas, should be much simpler.

Just out of interest SC is peat still cut on the Island for fuel? Or was it never used on Mull?

There’s lots of evidence still around of old peat diggings. Don’t think it’s done on a commercial bases anymore. I think there’s still the odd one or two old timers that still dig and burn.

Just out of interest SC is peat still cut on the Island for fuel? Or was it never used on Mull?

We still do it here in Ireland, I live on the bog but I don’t dig or cut myself,  buy a trailer load from a neighbour who does. The use machines now like big extruders behind 4 wheel drive tractors

We love our home. We didn't build it, but it was a 150 year old stone built derelict 2 into 1 cottage. We did it on a shoestring. 65k for house and just under 30k completely gutted and rebuilt inside. I drew up our plans myself to go to 4 beds, and wish we had decent advice to call on.

We don't have gas as was 10.5k to get mains here we were coal central heating with extra wood burner, but added oil a year later. We suffer still with damp, and struggle as our house stays cool. But I love it. Really want some other heating source but sadly no money. We search for our wood for free.

The garden at back is our paradise as the parents of old couple I knew here, kept the seperated back garden for the terrace of 5, so it's a decent size, plus side garden and front. Drive at front, 4 car parking bay at back, plus annoying 6 garage and turning area that we only own land underneath on. 2 of the garages are ours.

(Mike would you know how I measure to replace broken back door please. I can look around, if I know what to look for. My shoestring window and door guy has vanished)