ProDave

I have just checked and our joists are about 280mm overall depth. they are all on 600mm centres. Most of the joists are about 11 metres long. they don't span 11 metres of course but run end to end of the building with intermediate support from the wall either side of the stairwell. The only difference in the "downrated" ones that only span the 4 metre gap is the timber used for the top and bottom chords is thinner. Generally the floor is pretty solid but as I noted on that bit with the downrated joists there is some noticable bounce so had I anticipated that, I would have specified the same joist size throughout.

It only lists up to 10 instances of a particular house name from all over the UK. So I can't tell how many houses there are with the same name as us. But if you narrow it down by typing part of the postcode I find there are only three in the IV postcode area (4 counting ours that is not on the list) the nearest being 12 miles away.

Not quite my understanding? They will have to tell you what their cheapest rate is and what new customers would be offered. Not quite the same as automatically giving that to you. I will bet you still have to request it.

I take it your present boiler is a combi? so no hot water tank. So you really need a hot water tank or a Sun Amp so your chosen HW storage can be heated by solar PV and self use more of it. Advantage of a HW tank is it can be heated cheaper by the gas boiler when there is not enough PV. Advantage of a sun Amp is much lower standing heat losses. Some of them can also be heated by the gas boiler so perhaps choose the version that can? If you don't want to change the boiler it is possible to use a "combi" to heat a HW tank or sun amp, though it will be a bit unconventional.

It has surprised me how much of our PV we can self use. We only have a 4kWp system with a 3.68kW inverter so it's not hard to use most of that. Export really only happens if the HW tank gets to temperature too early, and that mostly happens when we are on holiday so not using any. Otherwise when the inverter is flat out, and the immersion heater is on, then surplus is only a few hundred watts. We have some shading issues as well which reduce total generation so that too makes it easier. I should see soon as we move into spring if some tree felling over winter has made much difference to that. But once you go over 4kWp it becomes harder to self use it, and that is where I think battery storage would help. At the moment I see little merit for us installing any battery storage, though I am sure I will later when prices fall more.

I doubt many static caravans used on a self build will ever find their way back onto a caravan park of any description. Most sites have strict rules about age and condition, and most statics we get to buy for self build have "done their time" on a caravan site. Just be careful if installing a wood burner. I had some nice assorted slabs of granite for mine:

As many of you know I have refused to pay the council house naming tax. We just chose a name and started using it. The result of that is it appears on every known database, including the councils own street naming database, DNO and telecoms databases, even the OS land registry map has the house name on it. The only place it does not appear is the Postcode Address File. And it will only ever get there it seems if I pay the council £100 so they can notify Royal Mail. RM won't accept notification from any other source. At least that also meant nobody could object to our chosen name. I did check first there were no other similar names close to us.

Is the export tariff really worth it? At 5.5p per unit, I have only exported 127 units in the last year, so I would have received the princely sum of £6.98 Mine is DIY installed. Imagine if I had had to pay the premium of an MCS install? The small export payments would never ever recoup the extra cost of that.

I like the Australian numbering system. My BIL's address is 999 Emerys Bridge Road. That means it is 9.99 kilometers down the road from it's start. That makes it easy for deliveries and emergency services.

3 phase boards are normally vertical with the mcb's on their side. What are the actual constraints you have to work with?

We were influenced by house names around us which a lot were based on trees, woodland etc. We have a burn through the garden but our neighbour is already called Burnside. Most of our trees are willow, so we settled on Willow Burn. The decision was influenced by the fact WillowBurn.net was available. Some other names were ruled out because no sensible domain name was available to go with them. If you want something more Gaelic, we considered Tigh Na Fein which is as close as I could get to self built house.

Yes a smart meter is needed and the PV install has to be done my an MCS installer in order to claim any export payments.

The best thing I did to our 'van was fit a wood burning stove in it. The worst thing that winter was crawling underneath it at about 10pm during a blizzard at the height of the beast from the east, with a hairdryer and extension lead to defrost a frozen pipe before it split. Cause by a mouse had chewed the pipe insulation off a section about a foot long.

That solution removes the main advantage of posi joists, the ability to easily run services and pipes etc through the joists.

We spent 18 months in a static caravan on site through the coldest winter for years (remember the beast from the east) That was just me, swmbo and our daughter. With 3 boys you are going to have to look at a much larger 'van than we had, possibly a twin unit if you want a bedroom for each of the boys? We had the washing machine etc in the part built house and I also had a desk and office set up in the house. That was where most stuff was stored as well. You need to seek out your local caravan dealers, there will be some and they usually have the large flat bed trucks to transport them. When finished you can just sell privately and the buyer will have to pay a transport company to move it. The one we bought however was actually advertised for sale on a site. We wanted it because it had a very unusual layout that suited us and had not seen one before, so we talked to the site owner and they were happy to sell it and have it taken off the site. I believe it just got replaced with a new one of the same type on that site.

I am surprised at the 253mm depth. For a 5 metres span we have 300mm depth, and it is a pretty solid floor with little bounce. Don't make the mistake we did however. One half of the house only has a 4 metre span. Most of the joists run through so are over sized (sized for the 5m span) But where they are interupted by the stairwell the engineer specified thinner top and bottom chords. The result is our bedroom floor has noticeable bounce on one half. Had I anticipated this, I would have insisted on the same size jousts throughout.

@gilesm if the insulation has been done like that in your sketch, then it looks like it has been done as a warm roof. But if that is the case, the loft and eaves void should NOT be ventilated. And the air tightness layer should be adjacent to the insulation. I would start by cutting an access trap into the void sections so you can crawl in there and have a proper look at how it has been done, and see of you can see where the problems are and hope you can get at them to fix it.

I generally agree with that. BUT, the new house I am wiring the customer has come up with something a bit different. Like aico they have decent terminations in their base but they are smaller. I will make a note of what make they are when I am there one day next week. He did say however they were not cheap.

A heating system is just a form of a "control system", something that was a main part of my employment in previous years. At it's most basic, any control system that overshoots has too much gain in the system somewhere (most of my control system work was to do with motion control) That may well be with a heating system that the slab is heated too hot, putting too much heat into the room for instance.

Why not? The main criticism given of mechanical room stats is hysteresis. but if properly wired they have a built in "accelerator heater" (just a resistor) that overcomes the hysteresis and makes them pretty accurate and tight.

The trouble with that, is you are supposed to maintain an air path between the eaves coombe and the ridge space to ventilate a cold roof. Done properly, the insulation will be touching the plasterboard and secure, leaving the ventilation gap between the insulation and roofing felt

I know HV work is expensive. There is a potential building plot at the top of our road but it has an 11KV line and transformer on it. The owner got a quote to have these moved, and the cost of doing so was more than a building plot would have been worth.

Where I want a nice finish to sealant, I use "Corner Tape"

There is no "easy" solution that I know. It is indeed a common problem, and boils down to lack of care by the builders. As an electrician, it is oh so common on a windy day to remove a switch or socket and be greeted with a howling icy gale coming out of the hole. This is true of the new build I am working on at the moment!!! My solution would be convert the room in roof section to a warm roof. This means the insulation would follow the roof line right down to the walls, so the triangle "coombe" section would be entirely within the heated envelope of the house. That makes it a LOT easier to detail. the bad news is I can't see a way to do that without completely stripping off all the plasterboard from the roof sections, sorting out the insulation, and re boarding. Anyone have any better ideas?

I keep reading this thread and I still can't fathom the "issue" All I can see is you want a wood chip delivery lorry to be able to deliver wood chips to where you want and the track goes under an HV line. You seem to want them to move or underground that HV line at their cost? That is one long list of work needed to re route it. Perhaps a picture of the "problem" would help our understanding, but I would be looking at ways to alter / improve the track instead to remove the hazard, that would probably be a lot cheaper? The DNO DO look after tree hazards. They regularly prune trees close to their overhead lines, and one neighbour got SSE to fell a very large Ash tree that would have taken out an 11KV overhead line if it came down. They paid the entire costs of felling the tree (which the neighbour wanted gone as it would have flattened his bungalow if it had fallen that way)