Ed_

Totally agree. It is not fair that the same areas get all the pain.

10 times as much land is used for golf courses as solar, yet it is solar that gets the bad press for "taking up prime agricultural land". Domestic cats probably kill 1,000-10,000 times as many birds as wind turbines, but we rarely hear that context. Most things we do are bad for nature, but some things are less bad than others. I wonder how much of the reluctance for renewables is simple NIMBY-ism. No one has tried to build a new fossil fuelled plant that recently, somehow I imagine it wouldn't go down too well with the locals unless replacing an existing one, which is probably not a viable strategy given our growing power demands.

Do you think ad hominem attacks help convince the undecided of your arguments?

Not one single Chinese offshore wind turbine has yet been installed in European waters. I suspect you must have seen the foundations, which are just welded steel. China produces some of what we use, but most are produced in Europe, or the Middle East. Unfortunately, like ship building, we struggle to produce major offshore steelwork in this country. Not just at a competitve price but just to fabricate it full stop There is however a new facility being built at Teesworks - https://www.seahwind.com/ - proper heavy industry. I pray it is successful.

It's not just the guaranteed minimum price, it is the price. If electricity prices are higher than the strike price the difference is paid back to (effectively) the government, if lower the government tops up. The owner gets exactly the price, no more or less, per MWh generated. It is the only way projects with huge upfront capital cost and low returns can be built. The cost of finance without certainty over return would kill them, its not at all like oil and gas projects which are generally far more profitable so can stomach higher project finance rates. That and oil companies can often fund off balance sheet rather than finance due to huge historic profits. It is the whatever the capacity entered into the agreement generates, for 20 years. Usually it will be an exact number of turbines' output.

Pre and post pandemic is a different universe for large construction projects, cost inflation has been brutal. There is, unfortunately, a lot of fake news around, like the recent loud protests in certain newspapers that the cost of net zero is £7tn. A figure that is deceitfully incorrect - the cost of net zero in the paper from which the £7tn is dishonestly derived is £380bn. Not trivial, but very different. The question is which generation source is the cheapest going forwards, given we need new generation, and it is probably pretty similar for renewables and gas taken as a system. What is not included in that cost and is arguably the most important factor is the uncosted effects - polution, climate change, funding of dictators and wars, volatility. Pick your poison. Oh, and an interesting point that is usually ignored is that given the highest cost generator sets the price for that slot, when considering the system costs of renewables you should account for the fact that if we didn't have renewables the electricity price every day would be much higher as it is the most expensive generators that it is kicking out of the mix. When you look at "gas prices" https://eciu.net/analysis/reports/2025/marginal-gains-how-wind-is-pushing-gas-out-of-the-power-market-and-cutting-costs I don't believe this is correct. Wholesale prices yesterday were around £100, that price will have been set by gas generation. I think you might be quoting the price of gas as being around £55/MWh. CCGT efficiency in converting energy in the form of gas to electricity is around 60% so that gives a price of £92, then there is the cost of the plant doing the conversion so that probably takes you up to the £100. This is an easy mistake to make because it is a favourite technique employed by media commentators who know better but for some unknown reason choose to mislead.

I dug the hole 8 weeks ago, so it wasn't oozing then, it was dry. Now it has 20cm of water which seems to be an equilibrium. Whilst i'm generally unconcerned about it not working perfectly, as overflow will run off safely down the gentle slope, I dont want to create problems I don't understand. SI report found perched water at around this depth, but the boreholes were quite far away. I think you are suggesting 200mm crate with 400mm of cover? This makes sense to me - thanks.

So i dug a hole, it drained away quite nicely - 40cm in <4 hours. All good I thought. Just been back to check and record it more officially and there was 20cm of water in the hole. Scooped a bit of soil out in case it was clay settling at the bottom but made no difference. I suspect I have perched water, as it hasn't rained much recently and it drained away in November, plus it is higher than surounding ground so unlikley to be the water table. If this is the perched water table, at a depth of 60cm, a soakaway seems unlikely to pass, as the minimum depth crate I can find is 40cm which if placed at 60cm depth only gives 20cm of cover which is probably a bit low. Does anyone know? My next plan is to cast around a bit to see if there is a better spot, where either the soil drains better or the perched water is lower. Would another option be to make the soakaway larger so it has enough volume even with 15cm of water in the bottom from the perched water table? Or has anyone done a rain garden with no overflow?

It seems to go away. No signs of flooding or waterlogging. The gradient is minor but still that would prevent any sort of flooding, the water would just run off. In the end there is a road at the lowest point, and if it gets that far it will enter the drains.

Houses. This is an urban area. All the houses up the hill, so far as I can tell, drain to back garden soakaways.

The foundations will be down to the clay, it's a basement so will be a sort of raft. Soakaway can be downhill and I could put it 15m-20m away I think. You are right, best to dig a hole and see what happens first.

It says to a depth of 300mm below the invert pipe. That will be fairly shallow, within my made ground layer. From part H the depth seems quite clear, but when I read about soakaways and percolation tests, a lot of the Information suggests I should conduct the test in the undisturbed layer, ie the clay below the made ground. I feel reasonably content that doing the test in the made ground will give me a representative result, and if successful a working system like the existing one, but I am hardly an expert.

No...

100mm. Attenuated to 2l/s, I think.

Doing a demolish and rebuild. Existing rainwater went to a soakaway, which unfortunately had to be removed. I have 1-2m of made ground over clay. Clay is, apparently, essentially impermeable. Don't bother with a percolation test they say. All well and good but I've been quoted £25-30k for connection to the surface water drain - 8m away across a quiet residential road! I'm sure I can find a cheaper quote, but got me back to thinking about soakaways. Clearly the existing soakaway worked, I'm on a very slight slope and I guess the water percolates through the topsoil/made ground downhill, slowly adsorbing, evaporating and eventually ending in the river. The advice on a percolation test seems to be to dig it at the level of the soakaway. If I choose a broad flat soakaway design, I'm sure I could bring this above the top of the clay layer and reasonably expect it to drain adequately. Is there anything wrong with this logic? It seems percolation tests aren't exactly very well controlled.

My understanding is that having the insulation on the outside is better for condensation, as it means the concrete is warm. Insulation on the inside and the concrete is cold so the condensation point moves to inside the wall, potentially.

I've been round the internal v external debate so many times. You are right but I can't work out what to do about the cold bridge through the ground floor slab. How effective is a bit of external plinth insulation going to be to stop that? At least external is continuous. Maybe I am worrying about nothing. Will add a drawing later to help!

It would, it just needs to be thicker obviously. I'm limited to 100mm insulation where the timber frame joins the slab at ground floor level, to give a drip edge to the timber frame insulation. So 250mm EPS for example is quite a step out and probably won't look great, hence why I was thinking PIR as the thickness needed for PIR above ground is about the same as EPS below ground.

I am building a walkout basement, this means that down the sides the ground level will slope, from top of basement at front to floor level of the basement at the back. I'm struggling to understand how to detail the above and below ground insulation. i think I need to use EPS below ground and PIR is not suitable. As it's below ground, I need less, so 150mm EPS is ample, but that won't work above ground, so I thought I'd use 150mm PIR above ground and that works about roughly equivalent. The issue I'm struggling with is how to detail the transition given the slope? Can I just butt them up, render over the top to just below ground level and put in a french drain? Should I cut the insulation to match the slope (with lots of wastage) or just get as close as practical using blocks? I was planning on just adhering directly to the concrete.

Not really an option unfortunately, can't impact drive due to proximity to sewer in the road, and anything else is expensive. If I have to I will put the Insulation on the inside, it's not the end of the world, just trying to work out whether it is internal or external because a lot of decisions depend upon it and it's not turning out to be a straightforward decision.

The other sides are battered back, so traditional formwork. I have 1m to the boundary, so 350mm piles and 250mm insulation doesn't leave me much working room!

I likely need to pile one side of my basement as can't batter back. Will be CFA piles in concrete. I would like to use external insulation, mainly to avoid cold bridging at the ground floor slab. If I have a line of piles, can I place insulation against that, then cast concrete against the insulation? Is that practical? I know concrete cast against piles is fine but can't get my head around what happens with insulation in the mix as well. Any experience gladly received!

About 2.5 weeks is the stand-up time it appears, it has now started to collapse! Nice to know I wont be spending money for no reason.

I'm 1m to the boundary. The current neighbour building is 2.5m and new ones will be 1-1.5m. Many reasons for a basement: More space - urban plot so footprint limited. Ground slopes- front is 2.5-3m above back, basement spans this slope so GF is ground level at front and basement is ground level at back. I have made ground with possibility of a slightly mobile slope so would likely have needed deep foundations anyway. As it is walkout it both becomes cheaper to build and more functional than a traditional basement. Hopefully.

No, this actually is the neighbour's, not me trying to cover up! 1m made ground over stiff clay (site of a former brickworks, 100 years ago), but with a severely sloped section that probably needs to be levelled for a piling rig to work, just out of shot to the left on my picture. This is my new focus, seems to me if I need to pile why not weld them up (or similar) and that is my boundary. Ring beam on top to put the rest of the house on and insulate inside. I'd been avoiding this as it seems like a retrofit basement method and i'd thought that implied high cost, but it could be the best solution for my constraints.