Jeremy Harris

It loses around 600 Wh/24 hrs, so is about 3 to 4 times more "efficient" than an equivalent thermal store.

I can answer some questions about the Sunamp PV. There are no controls, as such, just a four core cable, a cold water feed and hot water outlet (plus a PRV vent). The four core cable is protective earth, neutral, line and switched line. The line and neutral are permanently powered to run the internal controls, the switched line is normally fed with power from an excess PV energy diverter, like an Immersun or similar, but can just as easily be run from an off-peak supply, like E7. The thermal batteries start charging as soon as power is supplied to the switched line, at a rate of up to 3kW. When fully charged the charging circuit turns off. When there is a hot water demand, the flow of water is directed through the thermal batteries, that are then triggered to start the phase change process that releases heat, that's transferred into the water at a rate of up to about 30kW. As soon as the hot water demand stops, the thermal batteries go back to the rest state, but will accept more charge from the switched line, if it's available. The only control is an internal thermostatic mixer valve in the water circuit that can be set to give a comfortable hot water output temperature. In essence, the Sunamp PV works just like a very small thermal store heated by an immersion heater, but with very much lower losses. The expected life of the thermal batteries is over 20 years, I believe, and all the testing so far seems to suggest that they do not degrade or lose capacity with age.

There are a few key things about insulation and it's effect on the way the house performs, and, perhaps more importantly, how comfortable it is. The thing that is very often overlooked is that good insulation on it's own doesn't make a house comfortable, even though on paper it may seem that the heat loss is low. Having a high decrement delay factor is as important, perhaps even more important, than just having high performance insulation (and our basic building regulations requirements are definitely not high performance!). Decrement delay is explained fairly well here: http://www.greenspec.co.uk/building-design/decrement-delay/ If you choose to have a brick, block or other form of masonry external skin, then, although it does next to sod all in terms of decreasing heat loss, it will act to increase the decrement delay. This then means that very low decrement delay, but high thermal resistance, insulation, like PIR foam, can be used to get a relatively thin, high performance, insulation layer internally, relying on the masonry outer skin to help increase the decrement delay. It's a far from perfect solution, as the external skin isn't really where you want to the high heat capacity layer at all, but it does make bodging things to use conventional, pretty poor, building methods can be made a bit better. The better solution is to use a reasonably high decrement delay structure, that inherently provides good thermal performance as well. This then increases the thermal time constant (how long it takes the house to cool down in winter, or how long it takes to over-heat in summer) to the point where normal diurnal temperature changes have little effect; it takes a prolonged period of cold day and night weather for the house to need any heating, and conversely needs prolonged high day and night temperatures for it to over-heat. Rock wool is a pretty average insulation material, as it has average thermal resistance and a pretty short decrement delay. Wood fibre/cellulose has a similar thermal resistance, but with a much longer decrement delay, so tends to give much better performance in terms of real comfort, rather than the heat loss numbers on a bit of paper.

We have a 300mm thick timber frame, filled with cellulose insulation and battened and clad with larch on the outside. No blockwork, brick or whatever and no problem with either insurers or mortgage lenders. It's true the that online quote systems that insurers use, and that some lenders use, can't cope with what they call "non-standard construction", but that doesn't mean that it's either impossible to insure or mortgage, or even that it's more expensive to insure or mortgage, it just mean you have to ignore the online stuff and deal with either a broker or directly with a lender. The curious thing is that we've found that going through a broker for insurance has been a fair bit cheaper than insuring our old block and brick house using an online direct service, to the tune of around 30%.

Our Local Authority Building Control were great, very helpful, responded very quickly to questions and were good value. I guess there will be regional performance variations, but that may well be the same with the private building control providers, too. Over £2k sounds exceptionally expensive to me.

They are often referred to as shattaf showers, I believe. They form an important part of the cleansing before prayer, wudu, that every devout Muslim has to do after performing any unclean act.

Worth noting that there are quite a few helical pile solutions around, too, and Stop Digging isn't the only company doing this, there are others that have been around for decades, as helical piles are commonly used in civil construction, for things like big road signs etc. I believe some of the old Victorian seaside piers are built on cast iron helical piles, which gives an idea of how long they've been around. We were going to use helical piles at the first plot we tried to buy, as a solution to avoid a lot of archaeology under the site. Lots of advantages, including the fact that you can start building the moment all the piles have been inserted, as they are at full bearing capacity from the moment they are driven in.

If the cypress is, in reality, Leyandii, the Leyland Cypress, and if the group of these trees could, by virtue of their closeness to each other and the way they block light, be described as a "hedge" under the so-called "Leyandii" section of the Anti-Social Behaviour Act 2003, then you could possibly take action to get them trimmed. Left untrimmed they will easily reach 40f to 60ft high, and they grow pretty rapidly (hence the reason for them being marketed as "instant hedging" a few decades ago). It all hinges on whether they are considered to be "stopping reasonable enjoyment of your home", with reasonable being the usual legal test of the "in the view of the man on the Clapham omnibus". It does cost to get the local authority to investigate, and there's no guarantee that you will succeed in getting them trimmed, it really depends on how much of a problem they are. It's also worth considering the impact of any potential neighbour dispute, as these have to be declared if you sell the house.

Not sure I like the sound of that at all..................

As above, my other half always unpacks everything as soon as we arrive, and moans if there isn't enough hanging space or storage for other clothes. I'd happily live out of a bag or case, and often have to at some places we've stayed, because there wasn't enough storage space.

My experience is here somewhere, hell of a game getting hold of anyone in Openreach, they try exceptionally hard not to communicate with anyone............. As above, once you get hold of the local engineer things usually run smoothly, as they just bend their system to get around the failings in their management. My local Openreach chap was very helpful, arranged for grey BT56 ducting, hockey sticks, cast iron boxes and a roll of underground cable to be dropped of at our site, all free of charge, so we could lay it all, run the cables in and leave them coiled up ready for the connection team. The connection team arrangement was impossible to sort through normal channels, so the local chap suggested we had an "accident", with a digger snagging an overhead line and then calling an emergency number he gave me. That worked a treat, within an hour the emergency team arrived, spotted the rolled up cable waiting to be connected and grinned, realising exactly what had happened. Everything was very quickly connected and tested and we were then ready to have the house master socket fitted at a later date, after we'd decided who to get a phone and broadband service with.

Might be worth checking the Open Government stuff, as I believe this places quite a lot of obligations on LAs to make information freely available. Failing that, make and FoI request for the documents. They cannot charge for an FoI request unless the time taken to prepare the information and release it is excessive.

Sounds unnecessary. We have a single foul stack, with a rest bend at the base, and a straight run under the slab to a 450mm chamber. Because we can access the top of the stack, and rod up to the rest bend, that's fine as far as the regs go. Edited to add that I cross-posted with Dogman.

The guidance used to be extremely clear on this, but few seem to have seriously challenged some of these charges. No public body is allowed to charge more for a service than it costs to provide that service, to a non-commercial entity. Since the FoI Act, you can find out the costs of providing services, with a bit of painstaking effort. Unless the LA can prove that it costs that much money to provide a copy of a document, then you can challenge the charge. I did manage to do this around 5 years ago, when we were plot hunting. There was a nearby plot where planning had been refused, and it was very clear from the planning officers report and the decision notice that there were two reasons for refusal, over-development of the site and the proposal being out of keeping with the nearby Grade I listed building. Reading the file it was clear that the principle of development hadn't been ruled on at all, meaning that a proposal that overcame the two objections looked, in theory, to be acceptable (the plot is an infill plot, inside the development boundary). I asked to have a very short telephone call with the planning officer, to ask a single question "Would a proposal that was in keeping with the Grade I listed building and that was not over development of the site, be considered or not?". They wanted to charge me £90 to ask this single question, arguing that it constituted pre-application advice. I argued that, as a resident in the parish, I had a right to ask such a question, as I was neither the applicant or the landowner. The LA refused. I submitted an FOI request, asking what the whole cost to the local authority of 15 minutes of a planning officers time cost, including salary and other employment costs and overheads. It turned out that this cost was a bit under £10. I then said that I would pay £10 for a short phone call with a planning officer, and unless they could prove to me that they incurred costs that were greater than this they had an obligation to allow this and not charge me any more. They backed off, and actually let me speak to the planning officer without a charge at all!

As far as I can make out, you can't remotely use a Pi as a TOR router, as it sits as a "middle box" on your LAN, with one connection to the internet (via your home LAN) and the other as a wireless access point that you can connect to locally. What it does mean is that you can connect any wireless device within range to the Pi wireless AP, which then routes everything via the TOR network. The big downside is that TOR can be a bit slow, but it's pretty secure. I still think the best option when out and about is to run Tails from a USB stick, as that is pretty foolproof. It does mean having a device that will boot from a USB stick though. A more flexible, and faster, option is seems to be to set up a Pi as a VPN at home that you can access from anywhere via your home connection. That would allow you to connect to your VPN from anywhere in the world, potentially, and then route your traffic via your VPN. Effectively your traffic from wherever you are routes to your home, through the Pi VPN and then back out again. Not as secure as TOR, but more flexible. At the moment I use Nord VPN (pretty good, I've found, and relatively cheap if you buy a multi-year package), but that does mean having it installed on every device you use (the basic package allows up to 5 or 6 devices, IIRC) and it also means remembering to open Nord VPN and choose a country that you want to use. The latter can cause a few problems with web sites that geolocate based on your IP, like the BBC and some search engines, so you can find that you don't get the content you want or you get a search in whatever language your VPN server IP is based in. I've not looked too deeply into running Open VPN on Pi, but can say that running a cheap little Pi Zero as a wireless access point seems fine, I've even streamed HD video through it with no problems, despite the fact that I'm using two USB connections either end of the thing (I suspect they may well be the real bandwidth bottle neck). The Pi Zero W seems to offer the advantage of not needing a USB hub, and having a direct wifi capability, rather than needing a USB dongle, so probably can't be worse in terms of performance than the basic Pi Zero. The Startech USB 3 Ethernet adapter looks good if you've got devices that support USB 3, but, AFAIK, few of the small single board computers do. The RPi doesn't support USB 3. It's pretty easy to squirt up to half an amp up the unused pairs of a Cat 5e cable, with surprisingly little voltage drop, even over fairly long runs. It's a bit of a Commando bodge, and not an officially supported PoE method, but you can buy cheap Chinese Ethernet adapter leads that have power plugs and sockets on for doing this, making it an easy system to put together. I run our VDSL modem like this, to save having another wall wart power supply next to the master socket, and to allow it to be battery powered as a standby system.

It was six that escaped, but their bite isn't usually fatal for humans, just bloody painful (I found out by accident - do not try to handle a male Chilean Rose just after it's moulted - it will be VERY teasy..................). Luckily we were exempt from the H&S@WA at the time, so it was just viewed as a normal eccentricity from one of a bunch of pretty eccentric scientists.

The two remaining ones grew to adults, pretty big, maybe 100mm or so leg span, able to kill and eat a small frog (we conducted an experiment, resulting from a bet..........). The 6 that escaped may well have survived. A couple of months later one of the cleaners said she'd seen an extremely large spider early one morning, which we sort of guessed may well have been one of the escaped tarantulas......................

When I worked at a research establishment down in Cornwall, one of the young scientists in my team bought a Chilean Rose tarantula as a pet. A few weeks after he got it home, it created an web ball and laid a few hundred eggs. He soon had a few hundred tarantula spiderlings, and needed to find homes for them very quickly (they eat each other if they all stay in one tank). I offered to take 8 of them, and quickly built a silicone-bonded glass tank, with 8 compartments, very fine mesh for the lid and temperature controls to keep them warm. My other half was absolutely adamant that she was not having 8 tarantulas in the house, so I set the tank up in my office. It became a bit of a feature, especially as I used to have boxes of live African crickets delivered to the Main Stores, and they got curious about both the labels on the boxes and the noise coming from them. Unfortunately, we had an incident one night and 6 of the things escaped. We never found them............

I know this isn't building related, but knowing there are some RPi folks here, I thought it worth asking. A bit of background; I have built a RPi zero remote camera, with a wifi dongle and directional antenna to get a wifi signal from the far end of the garden to the house. Because I didn't want to use the house LAN and wifi (mainly because I needed a wifi AP in the end of the eaves space to be able to receive the signal OK) I built a wifi AP using another RPi Zero, plus a Zero4U four port USB hub. This has a wifi dongle plus a USB to Ethernet dongle and runs a separate wifi network, on a different channel and subnet to the main network. The Ethernet cable connects to the wired LAN in the house. This works well, it keeps the camera system separate from the main house wifi and yet is easy to access. The plan is to have a dedicated CCTV server (using another RPi and a HDD) eventually, so I can run a low power, battery backed, security system, with 1080p video (the RPi camera is excellent, BTW, especially with a decent IR illuminator for night vision). Anyway, I was idly pondering the power budget for the battery back up system, and had the idea of swapping out the current PiZero plus Zero4U hub, plus the wifi dongle, for a Pi Zero W, with built in wifi. I could then fit a micro USB to Ethernet adaptor, run PoE up the spare pairs in the Ethernet cable and have a neat, single board, lower power, wifi AP for the CCTV. Having had this thought, I then wondered whether I could set up another Pi Zero W in the same way but as a wifi AP plus TOR router, rather like the Ladyada Onion Pi. I rather like the idea of having a secure, short range, TOR-enabled wifi network, or even one that was just running OpenVPN (save me having to remember to turn Open VPN on and off all the time - sites like the BBC get upset if you seem to be outside the UK...............). The question is, does the Pi Zero W wifi allow use as an AP? I've dug around the usual Raspberry Pi sources of info, but can't seem to confirm whether the Pi Zero W will work like this or not. There's a bit of a dearth of info on the Pi Zero W, generally, other than some having problems with wifi drivers. This is probably to be expected given that the Pi Zero W is relatively new. I've ordered a Pi Zero W to play with, but if anyone here has tried to do something like this I'd be interested to hear their experiences. I can confirm that it's pretty easy, if a bit tedious, to get a Pi Zero plus USB hub, plus dongles, working OK as an AP, although there is a lot of duff info (probably just out of date) on some of the config file entries needed to make this work OK.

I was originally going to fit 2 solar thermal panels and 23 PV panels, as I could get ones that looked identical and all the plumbing would be hidden by the system being in-roof. The cost of the solar thermal was prohibitive (over £3.5k, compared with a few hundred for two extra PV panels. The real killer was the very poor heat transfer rate when the tank is partially warm. Solar thermal has a shorter useful window where it delivers practical heat levels compared with PV, that will deliver the full panel capacity for any given level of insolation, irrespective of the tank temperature. This difference was enough to erode the apparent efficiency advantage of solar thermal to only a little bit better than PV, and that, coupled with the much reduced cost and very low maintenance of PV made the decision to fit 25 PV panels a no-brainer. Ed Davies has done some excellent work comparing PV and solar thermal on his blog, and it's well worth a read, even though it's now a little out of date with some of the price comparisons: https://edavies.me.uk/2012/01/pv-et-flat/ https://edavies.me.uk/2012/01/solar-per-area/

Just divide the measured air leakage rate in m³/hr by the volume of the house, in m³, and you should get the ACH figure. For example, our house measured air leakage rate at 50 Pa was 199m³/hr, and the house internal volume is 462m³. 199m³/hr divided by 462m³ = 0.43 Air Changes per Hour (ACH).

I took one look at the cutaway sample Biodisc at the Swindon self build centre and was just completely horrified that any half-way competent engineer could design such a thing. The whole concept of having the motor, drive belt, bearings etc, INSIDE the effluent chamber seemed so inherently daft that I could only imagine that the designer never thought for one moment about the consequences of such a design for maintenance and longevity.

If you have the actual air leakage test figure from the air test report, in m³/hr, then you can use that, together with the calculated internal volume of the house, to derive the ACH.

I ran our water pipes in ducts under the slab, for two main reasons. The first are as Mike has said, the second is that sooner or later there is going to be a mains water connection available in the lane in front of the house, as the 80+ year old cast iron pipe that's there at the moment will have to be replaced before long. I wanted the option to have an easy mains water connection if it became available and if we felt it worthwhile, so I ran an extra 100mm blue duct to make pulling a pipe through a lot easier in the future. This duct also runs under the path around the house, and terminates close to the boundary, so a short trench and a bit of new pipe and we could be easily connected at probably the minimum connection charge. The duct is sealed at both ends, and has a foam plug in the house end to prevent heat loss.

I got to stand around 30ft away and alongside from one of those, the Shuttle Crawler, as it was coming back from a launch to the Vehicle Assembly Building. It's reassuringly large.