Dreadnaught

Would you be using the PCM 34 of 58? 58 I assume. But, I wonder, is there a role for a PCM 34 cell too, @le-cerveau-style? Presumably not. Which makes me wonder why @le-cerveau went for both types of cell, especially when PCM 34 has had some issues, although I think those issues are now resolved. The mantra I thought I had learnt early on in my research about PCMs was that the input (not output) temperature defines the PCM to be chosen.

Here's a Wikipedia article on LEED's parent non-profit US company: https://en.wikipedia.org/wiki/U.S._Green_Building_Council And on LEED itself: https://en.wikipedia.org/wiki/Leadership_in_Energy_and_Environmental_Design

Do you mean this https://www.livehome3d.com ? It does look good. Tempting. Shame you can't import a house plan directly from Sketchup or AutoCad (but you can trace it).

Thank you. That's nice and simple. Yes, I suspect the council will want evidence of permanence. I was mentioned, unprompted, on the phone when I called. Interesting question. Here's a picture of the device. It connects to the outlet. The hose is suspended vertically in the water to terminate just below the surface by the floating ball. This ensures a constant head of water so constant pressure so constant flow rate. The top of the hose connected to the ball, with the brass connector, has a mesh filter. Clever! To adjust outlet flow rate, if desired, I assume you can adjust the length of the link to the ball. A longer linkage would increase the flow rate, shorter would reduce, as this defines the pressure from the head of water above.

Benchmarks database…

Thanks @epsilonGreedy. And then Gault Clay underneath all the way to the centre of the Earth (or at least that's what the borehole that went 10m down suggests)

I admire the cut of your jib, @Russell griffiths

Fortunately that I do. I am a bit concerned about what such a tank should stand on. It will be 1.5 tonnes when full of water on a base that is 120 by 78 cm.

Good question. I think it is suitable. But I will double check with the supplier. Unfortunately, I can't have a crate-based soak away because none of my site is 5-metres from a building (a building regs restriction I think). Therefore the rain water will go into said tank and then drain slowly (at 2 l/s) into storm water drain in the road immediately in front of my plot and thence into the river just 40m away. Anyhow that's what I hope planning will agree to.

Thanks @PeterW. That's very helpful information. Am reading it all now!

After I posted this above, one of the online suppliers of tanks offered to do the necessary calculations for me for £200 + VAT, which would be reimbursable against the cost of a tank. Sounds tempting. Is that a good deal?

With your collective help, I have progressed a little further my drainage but now would welcome a bit more help. My roof area is 168 m2. The rainfall intensity is 0.014 litres/second/m2 from Building Regs. This gives a surface water drainage rate of 2.35 litres/second. I need to get this down to 2.0 litres/second for planning so am thinking to use an attenuation tank like the one below. This one happens to be 1,500 litres. How do I calculate the size of tank I need in a way that would convince my local council's drains person? Or is this the point where I need to involve an drains engineer? Any help appreciated.

Slightly off topic. Is it feasible to buy a comprehensive set of tools for resale at the end of a build? I saw such fine set when I visited @PeterStarck 's lovely build last year. In doing so, my instincts would be go for the most popular quality brand to aid resale. To me, Makita seems to be that based on reading on here over the time since I have been a member. I imagine the buy/sell loss could be modest by this approach but am I right? Is there a thriving second-hand market in Makita tools or are they like cars, depreciating precipitously?

Completely ignorant of these matters, but I thought the requirement was only for adequate provision, not for all sockets to be accessible by all. I took that as meaning only a middling proportion of sockets needed to be at accessible heights and even numerous sockets high and low (even on the floor) were fine.

Thanks @Ferdinand and @Russell griffiths. Very interesting. Ambiguity reigns it seems!

Out of interest, and at the risk of going off topic, I wonder if after planning an extra bedroom were added (by, for example, converting another room or moving a wall), but without changing the external appearance at all, would planning be concerned as some of their decisions seem to be guided by occupancy levels, such as the extent of car parking provision?

Its a wonderful exhibition down at the Portsmouth Historic Dockyard. Well worth a visit. I was last there just before they finished the treatment of the woodwork with polyethylene glycol so the ship was still covered with hoses and other contraptions. Keen to go back now all the pipework has been removed. As my nom-de-plume suggests, I have an affinity for old historic ships and all things Royal Navy

500 years isn't too bad going, at least for about half of the ship

Haha, thanks @PeterStarck. Perhaps I might, if I had your impressive ability! My problem is that my keenness is likely to overwhelm mine ?.

Good point. As @JSHarris also mentioned. That sounds like the answer. It is interesting to consider why the figures in Diagrams 1 and 2 in the Building Regs are so different. Both measure rain intensity but one is for gutter sizes and the other for underground drainage pipes. It is unclear to me why it pays to oversize gutters but not underground pipes.

Thanks @epsilonGreedy, yes please. That could help me put my home-brew numbers in a form that they might like & expect. Presentation matters!

Ah, I think you were right the first time @Mr Punter. Reading through it all, the rain-intensity figures for drainage come from Diagram 2, which also mentions "underground rainwater drainage", not Diagram 1 which is what I showed and is for roof drainage. As follows under "Section 3: Surface water drainage" … From diagram 2… So I should use 0.014 or 0.016 l/s. Now, I just need an exact measure of the roof area including the overhangs from my architects drawings. I suspect it is a bit greater than 120 m². But even if the drainage rate exceeds 2 l/s I suspect it won't do so by much so a little attenuation is all that I will need to hopefully fall into compliance and satisfy the drainage person in the local planning department. The drainage person was adamant that any attenuation device would need to be "permanently installed". I presume they have instances of a modified water butt doing the job which was whipped away as soon as their backs were turned. I am not sure what permanently installed means in this context. And she also said that a water butt would not do anyawy as it could be full on the day of a deluge and so do no attenuating. This has been very helpful. BuildHub continues to amaze! Thanks to everyone.

Thanks! When I look at the map in the Building Regs for Rainfall intensities below for "design of gutter and rainfall pipes (litres per second per square metre)", why is the intensity higher in East Anglia (0.020 or 0.022) than say Pembrokeshire (0.016) when East Anglia has some of the lowest rainfall in the country? Seems counterintuitive.

How would I calculate the drainage rate from my 120 sq.m roof area? I assume I need to find some standard figure for rainfall per sq.m in my area that will withstand scrutiny from the planners. Is that right? How then to convert that into a flow rate and a calculation for how big an attenuation tank I will would need to achieve a max flow rate into the storm-water sewer of 2 litres per second? Anyone know?

Ah good point. Thanks. You may well be right. I am sometimes too keen to try something new.