ProDave

I thought you had an electrician on the way? What has he found?

You don't want a smoke alarm in a kitchen otherwise it will go off if the toast gets a bit well done. We used Aico for all the house alarms, and Aico do a neat combined Heat and CO alarm combined in one package which we need due to the gas hob and WBS in the same room.

We prefer the whiter daylight colour. Forget the big brands, go to Screwfix and buy a few different colours and try them, Then when you find one you like but a job lot. I could never go back to the energy wasting of filament bulbs now. If I put every light in the house on, it's still only about 200W

I have also seen a steel gusset plate bolted to the web where multiple large holes were needed.

That also shows that right now I would be paying about 24p per kWh right now to cook the Sunday roast, which is why I do not want that sort of tariff.

At it's basic level, an ASHP has two pipe connections, flow and return, just like a system boiler. ANY plumber that can plumb a system boiler can plumb an ASHP The electrics can be a little more complicated, unfortunately every make of ASHP seems to have it's own ideas how it integrates to the rest of the system so unlike aq system boiler it's not just a set of standard wiring, but it is not that difficult you just have to read the manual and understand it. £2000 is way too much to install it. At a labour rate of typically £200 per day that would be a whole week for both the plumber and the electrician which is ridiculous. And £900 to commission it. No more than a days work. It's when you get prices like that, that many of us become sceptical that you are being ripped off with an over inflated cost, with the result the company are creaming off most of the benefit you will get from the RHI payments. And being charged £400 for a controller is madness, that amount of electronics in any other consumer product would be no more than £50 So if seeking an ebay bargain, try and find one that has the controller (if one is needed) No I was talking of adding a boiler programmer as well. I did not have to, but the programmer supplied with mine is a fiendishly complicated thing to understand and use. Yes it would do the job but I doubt anyone in the house would understand it. So I preferred to just leave that for setting parameters and diagnostics, and use a normal programmer that everyone understands to determine at what times of day it runs heating and hot water.

The extra "stuff" is just the same as for a normal system boiler. A couple of motorised valves, a pump perhaps, and if like us you did not want to use the programmer supplied with the ASHP then a conventional boiler programmer. Heat pumps work different to system boilers, they only ever heat DHW or space heating, never both together. This allows them to run at a different target temperature for heating and a higher temperature for DHW. I run mine direct to the UFH without issue. Some say you should fit a small buffer tank. You need to look carefully at whether it is worth going for an MCS install and claiming the RHI or going for a cheap install and not bothering. I bought a cheap ebay ASHP and self installed it though that was not without it's problems (the first one they supplied was faulty and I had to kick up a stink to get them to replace it)

Skeptical Does it absolutely capture 100% of the CO2 produced? If so how and what does it do to it? Or is it like burning wood, they are trying (and failing) to convince us that is CO2 neitral.

As the grid moves to renewable energy, most of that is somewhat variable. So in order to meet the peaks of demand, particularly when the wind is not blowing much etc, then storage is needed to store renewables when in surplus to cover the times of generation defecit. Without sufficient storage, you will never be able to decommission the last fossil fuel power stations.

I was about to post something to that effect. This is where grid scale storage is needed if we are ever going to get to a zero CO2 electricity grid. But electricity generation can never be negative CO2

That is a long standing gripe of mine. This is a term you won't hear anyone else use but when our house is complete and properly banded I will be in "council tax poverty" meaning 10% of my income goes to pay the council tax. They use the same thing "fuel poverty" when the 10% applies to your heating cost, so why do they think it is okay to be in council tax poverty with no option to do anything about it it?

Hard to answer until you know when. If it's summer, staying cool might be your problem. Your shed is insulated to near passive house standards compared to the 1" thick walls of the static caravan we survived in 2 winters ago. (I will never forget the beast from the east) which we kept warm with a 5kW wood burning stove running most of the time and electric heaters. As this is a one off, is it really worth the time and expense kitting it out with all the showers and stuff? A cheap second hand touring caravan will give you all that and treat the shed as a space to stretch out and relax as well as storing stuff?

I am not a fan of powerline stuff, that's a recipe for RF interference particularly of your radio reception is poor to start with. When we were living in the caravan but the phone line was connected to the house, I used a wired ethernet between the two and set up an old redundant BT router as a wifi access point. I wonder what is blocking the wifi in your house? Ours is a similar size to yours and not very dissimilar layout. Our BT router lives in the cupboard under the stairs which is pretty central to the house and we get good wifi in all rooms, even the loft space above the garage. It was only the static caravan another 30 feet away that was borderline so I connected the spare router to fill in coverage for that.

Yes it needs to be structural. The pug mix is only supported on thin OSB sheeting. For LVT lay a chipboard floor first. At 400mm centres 18mm would do.

When I had mine "done" by the nurse it was indeed a paper clip heated over a spirit burner.

This sounds to me a lot of complication and a lot of expense for what looks to be quite a small extension.

That is the floor make up I have. this shows what Peter is describing The engineered oak floor then spans across the battens.

Opposite problem to you. Sloping site. Ground floor level determined by garage floor level plus step up into the house. This meant at the far corner, FFL is over a metre above finished ground level and that is after raising the ground level at that side of the site. Then add it we already had to dig off a lot of soft organic top soil, it would have been a LOT if inert fill to bring onto site to build it up that much to make a solid floor. I actually "made it worse" by specifying to the SE that I did not want sleeper walls (I was trying to simplify the ground works and foundations) The floors have turned out very well. Yes they do bounce, like any timber floor but not excessively. Mostly engineered oak with some slate downstairs.

We have timber floors spanning 5 metres, JJI joists at 400 centres downstairs and posi joists at 600 centres upstairs. Both about 300mm thick. If you could get an extra sleeper wall mid span on some extra screw piles that would bring the span down to 2.9 metres and should let you get a thinner floor make up. A timber floor spanning 2.9 metres should be quite solid.

I suspect any change will be incremental, e.g expect 4G glazing to become common first.

What is the span the floor has to bridge? If going timber I would suggest sleeper walls, but that will need digging. How are you supporting the house with no dig? I presume screw piles and a ring beam? Could you add to that to make sleeper walls for intermediate support of a timber floor?

I would stick to an insulated concrete floor. just dig deeper and start the insulation deeper down so your ground floor level is lower. It will be a LOT harder making (in effect) a sunken timber floor. that will need ventilated space underneath it and air bricks etc so is not the normal way to go if you are trying to get your finished floor level lower.

I sometimes sail with a tpye 1 diabetic. For the last 30 years her doctor has been telling her she has a life expectancy of another 15 years, and still no major problems.

What is the cost? Nice though it is, I doubt it makes economic sense, When I looked Fakro were the only 4G roof light I could find at 4 times the price of ordinary ones.

Instead I get that 48kWh from an ASHP which on my single rate tariff of 14.183p per kWh and assuming a COP of 3, costs me £2.36 There is indeed a good case for direct electricity on an off peak tariff, but you do need a floor capable of storing that much. I doubt my timber floor / biscuit mix would. You really do need a decent concrete slab.