Jeremy Harris

The high proportion of non-contestable work is because this is an HV supply. HV supplies cost a heck of a lot more to move/change than LV supplies. In general, DNOs are reluctant to take HV supplies underground unless they really have to, even though they may need less maintenance, as they much prefer to be able to have easy access to cables. As the work also includes relocating a sub-station (I'm guessing that this is presently a pole-mounted transformer, from the reference to a terminal pole) then it doesn't look to be a bad price.

Just depends on the pressure across the restrictor, which will be determined by the flow velocity and the cross sectional area of the restrictor. The flow velocity in the duct needs to be low to keep noise down, and at trickle ventilation rates is likely to be around 1m/s and should not exceed 2.5m/s. The flow velocity through the restrictor will be higher, but not by the orders of magnitude needed to make a water filled U tube manometer work OK. The dynamic pressure of air at 1m/s is roughly 0.614Pa, or about 0.063mm of water in a U tube manometer.

I ended up watching a programme about private landlords last night (this: https://www.my5.tv/britain-s-council-house-millionaires/season-1 ). Interesting to see how some entrepreneurs were preferentially buying former local authority built houses, with comments that they were usually quite well built. Accepting that it was a very biased view of a small section of the private rented sector, it did show just how much money a few are making from buying up houses that were sold under the right-to-buy scheme. I'm biased, though, as I remain convinced the right-to-buy was an exceptionally flawed concept. Had local authorities been allowed to use the receipts from houses sold under the scheme to build more houses, then it may have helped limit some of the social housing problems we're seeing now. By banning or restricting local authorities from building new houses this scheme seems to have worked to make a few people relatively wealthy, without meeting the growing need for social housing.

Very hard to use for this sort of MVHR job, though, as the pressure difference is tiny. I tried to use a water manometer sloped at 30° (about as much slope as is reasonably practical) with my home made pressure test fan (which works at the very much higher pressure differential of 50 Pa) and even with stripes behind it to try and read the level of the dyed water it was still way to small to be accurate. The pressure differential across a restrictor is going to be a lot less than the 50 Pa use for an airtightness test, and 50 Pa is only about 5mm of differential height in a water tube manometer. The pressure across an MVHR restrictor at trickle ventilation rate is probably going to be under about 10 Pa, so less than 1mm of height differential in a U tube manometer.

The UK housing problem is really a consequence of the shift from manufacturing industry to a service industry based economy. That's resulted in a migration from the manufacturing centres of the country, that were mainly in the midlands and north, to the south, particularly the south east. This then resulted in house prices rising in that part of the world, pushing up demand for more housing. Go to any former big industrial/mining area in the UK and there will be empty/cheap houses galore. What's needed is to increase employment in those areas, and reverse migration to south east England. For years various governments have been trying to make this happen, and for around 30 years now any new public sector departmental move has to be away from the area defined as the "greater south east". This hasn't really helped a lot, but if anyone has wondered why departments looking after car registration, income tax, passports etc are in far flung bits of the UK, this is it. It seems that the government is still trying to shift things north, with HS2. Whether they will succeed remains to be seen. I have my doubts, as I don't think this sort of change is something the government, any government, can actually bring about. Governments, of whatever flavour, have been losing the authority to make big changes to society for the past few decades, with that role being increasingly dominated by large corporations and technology companies. Arguably, the biggest influence on UK society are now US-owned social media and internet sales giants. Facebook and Amazon probably have far more real control than any British government.

Just call it a pin joint instead of a hinge. Pin joints are often used in big construction projects because they both make erection easier and also make the stress calculations simpler.

The first big DIY job I ever did was fit a new bathroom in the first house we bought. I'd never touched plumbing, tiling etc before in my life. The internet didn't exist then, and I didn't know any plumbers. There weren't even any DIY sheds then, so I had to get all the stuff needed from the local plumber's merchant. The chap behind the counter there had the patience to give me some advice, and ensure that the bits I bought all fitted together OK. Fitting the new bath and shower went OK, the bit I screwed up was the tiling. It was functional, but far from elegant. At the time I did this it was out of necessity, we just didn't have the money to pay someone to do it. When I fitted a new bathroom in our second house it turned out a fair bit better. By the time I came to do all the plumbing, bathroom, kitchen fitting etc in this house I'd probably done maybe half a dozen bathrooms and three kitchens before, and I wasn't at all fazed by taking the job on. Everyone has to start somewhere, and anyone starting out now has the massive advantage over the position I was in decades ago when starting out, as everything is easily available online and the internet has loads of resources that show how each job should be done. A bit of patience, together with some practice on test pieces, and I reckon anyone could make a reasonably good job of it.

One great thing with plastic waste pipe and fittings is that they are cheap, so you can buy a bag of solvent weld fittings, some pipe and adhesive and play around with the stuff to get a feel for how it goes together. Well worth the bit of additional cost, as there's a knack in making good solvent weld joints and it's far better to make any mistakes on practice parts than on the real job. If you get a few solvent weld access plugs you can seal the ends of your bits of test pipe and then check for leaks by filling the pipe up with water. After three or four joints you'll probably get a good feel for how they work.

That seems to be how our LG condensing washer/drier works. TBH, everything dries so quickly on the drying rack thing that we never use the drier function. We've got used to not having fluffy towels, and I prefer the feel of air dried towels, anyway.

We found the same, especially the space taken up by the wall. We opted for a reinforced concrete filled hollow block retaining wall, that's nearly 3m high at the highest point. The main advantage was that it gave us about 1m more width which pretty much translated directly 1m more width in the house, because space was tight on the plot in that direction.

I'd assumed that was the Octopus Go cheap rate (that's currently about 5p/kWh). Our cheap rate (E7) is currently 8.148p/kWh, and peak rate is 15.729p/kWh.

Looks about right, but Pt is really the energy needed to heat the water, not the power, plus the incoming water temperature may vary a bit between summer and winter, but tends to be around 1m to 2m deep ground temperature, which for most of the UK is usually about 8°C. We just run two showers a day and rarely use the bath, and we find that our hot water energy use is around 3 kWh to 3.2 kWh per person per day, so between 6 kWh and 6.4 kWh per day in total. Our UniQ 9 kWh unit can just about meet that OK when heated from either excess PV generation during the day, or boosted from off-peak electricity at night. It would probably not be able to run a bath in the evening without boosting at peak rate some days. A directly electrically heated hot water system, even if run from off-peak electricity, will always cost more to run than a gas boiler. The advantage of the Sunamp is really that it has lower losses than a water tank, so is more efficient at storing hot water, particularly in summer when heat losses aren't useful in terms of helping keep the house warm. The Sunamp is also a good match if you have a PV system, for much the same reason as it's a bit better than a hot water tank. I doubt that a 9 kWh Sunamp would meet your needs without being boost heated during the day, to provide the hot water for the evening bath. The recovery time is just the input power divided into the energy taken out, so if 6 kWh was taken out for showers, then the recovery time would be a bit over 2 hours (the 2.8 kW power rating is at 230 VAC, and the average UK mains voltage is about 240 VAC, so the power input will probably be a bit closer to 3 kW). We find that we always have enough hot water, and it's not often that the Sunamp doesn't get a bit of charge during the day from the PV system. Today, for example, our Sunamp was fully charged by lunchtime, thanks to the bright sunshine we're having.

I also can't see what the problem is. It's pretty common for attached houses to share a single foul drain, and also fairly common for two or more houses to share a private sewage system (be that a septic tank or treatment plant) if they are off mains drainage. I'd have thought that if you shared a private sewage system then that should have shown up during the purchase, as usually there are conditions included that define who pays for what in terms of maintenance etc. If it's just a shared foul drain that leads to a main sewer, then the run of pipe to the main sewer from the house may well be the responsibility of the water company anyway.

We have exactly the same arrangement, extract terminal above a pulley maid in the utility room. Works very well indeed:

As above. As a word of caution, best not to try and sand it off, as some of the older stuff had nasty fibres in it. Some types will come off with steam, but generally the easiest way to deal with it is to skim it, as @Simplysimon says. Do you have any idea as to how old it is? In general, the older stuff was dodgier than the stuff made in the last 20 to 30 years.

I reckon the two of you are around 8 to 10 miles from each other.

I'm afraid so. The Model 3 non-compliance is a real nuisance, as the last two cars I've had have had no problems at all with the charge point controlling the charge. The 6 A minimum is nuisance, but is reasonable, as the car onboard charger (for any EV) will tend to lose efficiency as the current decreases (just because a lot of the losses are fixed, and don't scale with current well). As a general rule, the higher the AC charge current (within reason) the better the charger efficiency.

Yes, a DP disconnects both L and N. The advantage of this, for an all RCBO board, is that it is safer, as it provides protection if there is an E - N fault. A split board with two DP RCDs and MCBs for each circuit (which is the minimum required by the regs) provides DP earth fault protection for all circuits, but does mean that any such fault takes out half the circuits in the house. An all SP RCBO board is OK, and means that an earth fault only takes out the affected circuit, but it doesn't necessarily provide protection against all faults; an E - N fault might not be be reliably detected. An all RCBO board, with DP RCBOs, provides protection against pretty much any fault condition, and also means that only the faulty circuit will trip, leaving all the others working.

I have a suspicion that the populated RCBO boards that ECD sell probably use their SP RCBOs, rather than the DP ones. ECD don't seem to sell the staggered DP busbars, either, although SBS do, I believe.

That's similar to the one I use to control my charge point. Easy enough to wire one of those to a contactor.

I don't think so. The snag with the SMA Sunny Island is that it apparently has similar behaviour to the Powerwall, in that it can seemingly charge from the grid even when it's not supposed to.

I've bought some of these to try: https://www.electricalcomponentsdirect.co.uk/acatalog/Compact_Mini_RCBO_Circuit_Breakers.html First impressions are that they are extremely similar to the SBS ones and seem to be well made. Reasonably good value for DP compact RCBOs. I believe that ECD may do a metal board populated with these for a reasonable price.

The Lux Power AC units disconnect from the mains in about 10ms and island the maintained supply circuit in the event of a power cut.

My view of Tesla is that their work model seems to be "release an update and let our customers find what's broken". . . A lot of Powerwall owners didn't even know that Tesla had rolled out the Storm Mode update here in the UK, and only found out over the past few days when their Powerwalls opted to 100% charge, irrespective of the power source, in readiness for a power outage. If I had one and it had done this I'd not be a happy customer at all. I want control so that I can decide when and from what source the system charges, so, for example, if we are going to be away I want to turn off off-peak charging, but still allow excess PV generation charging, and I definitely do not want the unit to decide to charge from the grid because some algorithm has predicted that bad weather is on its way.

The Lux Power AC systems look very controllable, and are top of my list at the moment: Lux-Power-Hybrid-Inverter-Datasheet.pdf