Jeremy Harris

The really massive problem with tidal power, is that although we have locations where there is the potential for a lot of power generation, like the Severn Estuary, the interests of those keen on exploiting this large energy source have to be balanced against the interests of those keen to retain both shipping access and important tidal habitats. The same goes for other areas where there is a high tidal range that could be exploited. The act of removing energy from a tidal stream has a direct and massive impact on the local environment somewhere - it's impossible to extract energy without that loss of energy appearing as an effect somewhere. Even putting solar panels on the roof of a house reduces the heat into the house by ~20%, which then impacts on things that may grow on those surfaces, by altering the mean temperature range. Arguing over the relative balance between the positive aspects of electricity generation, and the negative aspects of it is made all the more difficult because there are often somewhat irrational, but nonetheless strongly held, belief systems that come into play. The same people that get sufficiently irate to mount mass protests about electricity generation schemes are often the same ones that rely on the massive amount of electricity it takes to maintain the internet (currently the internet has an electricity demand that exceeds that of the UK as a whole, by a factor of about 8 to 10).

There's quite a few such systems around, ranging from buoys with internal winches that drive generators as they are pulled up and down, though oscillating air column generators using submerged towers a bit like some oil platform ones, to the far more powerful tidal barrage schemes like the one at Rance :https://en.wikipedia.org/wiki/Rance_Tidal_Power_Station I believe there are still trial tidal flow generators, like this one that's been use up near Orkney, where the tidal flow rates are quite high: http://www.opusenergyblog.com/floating-tidal-turbine-off-orkney-islands-breaks-generation-records/

FWIW, the first plot we looked at building on needed piled foundations. To try and get a feel for the cost of these I looked at several options, and all of those companies came back with a price that included the piling and the design and construction of the ring beam support needed for the house design we intended to build. Not sure how commonplace this is (the plot was just over the border into Wales, along the Wye valley) but it was a feature that interested me as it seems to be one less things I needed to worry about.

Just to be clear here, as it seems we have a professional trying to convince members that the use of his, or a similarly qualified professionals services are mandatory for self-builders, I can say with certainty that there is no requirement to use one company to manage this for you, You can coordinate it yourself if you understand the requirements, plus BC will quickly tell you if they need more information, anyway. Many foundation system providers, including the system we used, include the full structural design, including an SE's assessment of the ground conditions and the appropriate design elements needed to ensure the foundation system is OK, within their package. If you go to Isoquick, Kore, Supergrund of any of the other package passive slab foundation suppliers, or any of the specialist piled foundation suppliers, you will find they all offer a signed off design within the package price. I know this for a fact, as before settling on using our chosen builders package I checked out all of the about passive slab suppliers. Similarly, most timber frame suppliers, including those offering closed panel construction system, SIPs etc, will provide the required structural evidence needed. They produce this when doing the frame design from the supplied drawings, and all those I spoke with (around 5 or 6 different companies) all offered either accreditation for their build system or a drawing pack with calcs for BC. There should be no need for going to a separate SE to obtain calcs and drawings for the structure, unless opting to stick build to your own design. There's a lot to be said for using the pack produced by the supplier, as they will have produced similar packs many times in the past, in all probability, and so will be familiar with the process. I've a stack of stuff I collected back in 2012/2013 from when we were trawling around possible builders. All include details of the structural sign off that is included in their package.

Why did I need to? It's all over their website and several here used the same company, in part because their accreditation applied here.

Precisely, which is why, quite properly and correctly, our BCO accepted that their construction system was compliant with the requirements of Part A. At risk of involving the forbidden "B" word, I rather suspect that most of the interoperability agreements between the UK and ROI will continue, as so many of them were established before either country joined the EU. I also suspect that those bodies that currently EU Notified Bodies (as I was was, once) will remain so, as there is no requirement to be an EU member in order to be one (there are NBs in Japan and China, for example, issuing approvals to EU Directives and ISO standards).

So why is a house construction system that carries an NSAI certification (which the UK recognise) as an accredited construction method, with structural warranty, any different?

In a previous life, I was a head of type approval for all UK maritime radio, radar and comms equipment. That meant scrutinising reams of evidence from testing and manufacturing standard compliance documentation to ensure that a raft of EU safety standards were complied with. It was completely normal to trust some self-produced evidence, on the basis that the manufacturer had used a recognised competent authority to gather it and check it for compliance. The parallel here is much the same. The timber frame company produced a detailed set of drawings with structural calculations that were signed of by a reputable SE and they gave a ten year warranty. The structural requirements were warranted to meet the equivalent Irish specification to Part A, and agreed as such in the pack. Our BCO saw no need to go through every page of that checking again, he just took it on face valuie that an accredited company would be working within the terms of their accreditation. I see nothing wrong with that in the way that building control is supposed to work. A friend of mine works for a pressure vessel accreditation company, He spends his life looking at evidence that pressure vessels are safe and compliant and passes that information back to the regulatory body. The regulatory body don't come out and double check his work, they accept that if he's warranted it as safe and compliant on behalf of the manufacturer that';s hired him then it is. This is no different to a BCO relying on standard details for block and brick construction, and relying on the block, brick, lintel, timber suppliers etc and manufacturing their products to the standards they have said they would.

in your opinion. It clearly is not the opinion of Wiltshire Council LABC. Equally, it's not the opinion of other building control bodies. as I know that others have done much as I did and had their submission approved by their building control body. One has to ask why I was asked to give an afternoon CPD session to their inspectors if they felt that my submission was incompetent.

Not what I said. They accepted that the timber frame supplier had used a reputable and well-known SE to sign off the design of both the frame and the foundation, and they saw no merit in asking for copies of his work. I simply stated this in my submission and LABC accepted it.

I used Wiltshire LABC. As it happened, our build created a bit of interest within building control, so we had quite a lot of attention, including me being asked part-way through the build to spend and afternoon giving a CPD session for all the local building inspectors, a couple of planning officers and the conservation officer, at the request of our building inspector. Our completion inspection was by the head of local building control, as he wanted to see how a passive house had turned out (ours was the first passive house he'd seen). There was no indication of laxness. In fact, there were lots of photos taken, questions asked and examples of some of the innovative construction methods they'd not seen before noted, together with samples of some things like fasteners they hadn't seen before being taken.

To put some costs into perspective: We used a timber frame/foundation supplier who used their SE to do the frame structural calcs. None of these needed to be submitted to BC with regard to Part A compliance. All I sent the BCO with regard to Part A was a report from the passive slab supplier. Kore, detailing how the system worked. There is no requirement to use a SAP assessor at the design stage. It's pretty straightforward to do a design stage SAP and produce an EPC. I did it using the free version of the Stroma software, available to anyone, took me maybe a day to understand how to drive it and gather the data needed. Not hard to do, and saved a couple of hundred pounds. I did the outline design, site plan, foundation and services layout drawings for our build. Our timber frame supplier did detailed structural drawings to allow them to manufacture the frame components, but building control weren't interested in these - the BCO was more than happy to just accept the reassurance that the timber frame supplier was using a competent and methodical approach, signed off by their own SE. The total cost to me for our building control full plans submission was the fee to LABC. Off the top of my head I think this was around £650, and included all inspections (but this was in 2013).

Good points. The US electrical system has some features that make it safer than the UK system, and lots of features that make it less safe (IMHO). The 180 deg bi-phase 240V LV supply system, with N/PE at mid-line potential, is a plus, as the maximum potential between any line and ground is 120 VAC. The radial wiring system that's universal in the US is also plus point, in my view. However, the really. really crap design of US plugs, the complete absence of fuse protection on appliance supply leads and the near-total absence of protective earthing, together with the absence of switches on power outlets, are all serious flaws. Arcs are far more likely in US wiring schemes, as the absence of outlet switches, means that the probability of plugs being removed under load is high. This pretty much always generates a disconnection arc, and a look around pretty much any US outlet will show marks where this has already happened. Fitting snap action switches would probably remove the risk of most disconnection arcs on US installations.

If you have time to do a bit of research, and learn some drawing skills (if you don't already have them) then it isn't at all hard to do your own full-plans building regs submission. I had never done one before, so didn't really know what was needed/expected, but had a go, and was only asked to provide a few fairly minor points of clarification. Not a massive amount of drawing work needed, most of my time was spent reading the building regs (more accurately, the approved documents), in particular, sifting out the large amount of stuff in the approved documents that wasn't applicable. The bottom line is that a building regs submission for a fairly conventional house is not a lot of work, and doesn't require someone with a great deal of expertise. It's well within the capability of anyone with a bit of spare time available to learn some stuff and produce the documents needed. I can provide a link to my blog entry that covers our building regs full plans submission, with the additional information requested, if that would help.

Just to clarify, there are two surface resistance elements that have to be taken into consideration, in addition to the U value of the materials, to get the total U value. They are the surface thermal resistance on the inside and outside surfaces respectively, and they attempt to sweep up the conductivity of the air in the surface layer and the emissivity of the material at those surfaces, along with some degree of forced convection on each. For a wall, for example, the surface thermal resistance is usually taken to be 0.13 m².K/W for the external surface and 0.04 m².K/W for the internal surface thermal resistance. These thermal resistances need to be added to the other thermal resistances in the build up of the element and then the reciprocal of the result take as the U value.

Shouldn't be too hard to make an accurate light/laser distance measuring system as a reference. Many years ago I made a system for measuring distance when cave surveying (before laser distance measures were affordable) that used a tiny red diode, intended for us in fibre optics, collimated through a lens to a near-parallel beam about 20mm in diameter, that was sent to a distant retro reflector (a big bike reflector) and then bounced back to a 50mm lens (taken from an old camera) that focussed the reflected light on to a fast photodiode. I solved the problem of how to try and measure very short times of flight, buy just modulating the red LED with a 100 Hz sine wave. Part of the light from this LED was sent via a small hole to another photodiode receiver. Both photodiode signals were amplified through identical tuned amplifiers, centred on 100 Hz. The outputs from both amplifiers went to a dual comparator, that was gated to produce a 100 Hz pulse train with a pulse width that was proportional to the phase shift between the transmitted and received light. It was dead easy, even in the 1980s when I built this, to accurately measure the width of a pulse at this sort of frequency, with a high degree of precision. The pulse width was directly proportional to distance, and pretty accurate out to the limit imposed by the power of the red LED. I tried an IR LED, which gave a much greater range, but being invisible it made the instrument much harder to use in a cave. The red LED provided a very visible indication when the beam was aligned with the retro reflector, lighting it up very clearly, and as both the transmitter lens and receiver lens were mounted in the same machined block of aluminium, wherever the transmitter pointed the receiver was also pointing. Pity that red laser diodes weren't available then, as they would have massively improved performance. As it was it made cave surveying a lot quicker, as I included an electronic inclinometer in the box (and old Mk46 torpedo attitude sensor), together with an ex-sonobuoy flux gate compass, and a data logging capability, so pressing one butting recorded bearing, distance and elevation angle, which was all that needed. We'd often record each survey leg twice, taking both a forward and backward set of measurements, and always survey in a closed loop if possible, so we could use the least-squares error correction method on the 3D data set to evenly spread all the errors and get the loop to close. Heck of a lot easier than surveying with a handheld compass, inclinometer and fibron tape (which used to get really muddy).

Sounds a good compromise. I was really pleased with the way our planning officer handled our application. It was late, due to lack of resources in the planning department (one of the planning officers had recently left and not been replaced). The planning officer kept me informed, answered questions readily and was helpful when we ran into a conditions conflict between the EA and highways. He was also pragmatic when dealing with my requests to change some of the external finishes and materials, and dealt with them on the basis of me sending him photos. He also agreed, at the last minute (due to the delay between the end of the consultation period and the recommendation going to his boss for review and final sign off) to my request that the condition removing PD rights wasn't justified, and deleted it without question. Despite the delay in sending out our decision notice (it was around 3 weeks late) I mentioned the planning officers name to the council chief exec, telling her that I was impressed with his service (in the hope that it might get back to him). I felt that 99% of the problems in the planning department were caused by under resourcing, at every level. It took weeks to validate a pretty straightforward application, a delay that I'm convinced was just being used as a way to control workflow, and delayed again after the planning officer had made his recommendation and written the draft decision notice (which I obtained unofficially, with a strong proviso).

Welcome, sound like you're well underway. I look forward to seeing your more detailed questions.

I'd have a think about the consequences. I would guess that if you used your entitlement to claim the fee back, then you would be granted it. However, there may well be a process within the local authority that gets set in motion by refunding a fee under these circumstances, and that process may well include a review of the performance of the planning officer that dealt with your application. This could possibly have an adverse impact on him, so the judgement call is really whether or not you feel that he needs to be brought to task for the apparent mishandling of your application or not.

Failure indication is an art all to itself. There are several general rules pertaining to how failures should be indicated, the most common being that things should fail safe, and that means either switching off and waiting to be noticed, providing some sort of alert that something has gone awry, but doesn't require immediate attention, to something has gone awry and you need act immediately. In a domestic environment there aren't many failure modes that fall into the "you have to do something immediately" category. Fire alarms, and possibly flood alarms, are probably the only two that I can think of. A freezer failure is a lower category, as there is no need for immediate action if a freezer fails, there's usually an hour or two of leeway. Many MVHR systems have their own alarm/alert systems. Our's has an alert when the filter needs changing, but doesn't have an alert in the power fails, other than the display on the wall turning off (which is probably as good as anything). Some stuff is self-indicating mechanically, like MCB, RCBs and RCBOs - a glance at the panel shows if any have tripped (but not why, in the case of RCBOs). The problem with using indicator lights to show when something has failed is that the indicator lights themselves maybe as prone to failure as whatever they are indicating the status of. The best example I can think of are things like the caution and advisory panel lights on an aircraft. These light up a caption, and may also make a sound, whenever something goes out of limits or fails. The way the risk of the C & A lights themselves failing is mitigated is by having a push-to-test button that is exercised as a part of the pre-flight checks, and which illuminates all the C & A indicators. A more fail-safe indicator is the dolls eye used to show that oxygen is flowing to a mask. This device is spring loaded to the eye is closed with no flow, and only opens when there is flow. If there is a leak in the mask etc, then the eye opens all the time, if all is well the eye opens and closes with each breath. I'm inclined to think that a house really needs a range of different alert and alarm systems, each specific to the system. As above, temperature drop beyond a normal limit would be a sensible one for a fridge or freezer. Absence of airflow might be a good option for MVHR. Fire alarms need to work on a change of condition that is a fairly reliable indicator of fire, without giving false alarms, so rate of change of temperature is a good option for a kitchen, whereas a smoke detector is a better option for a hallway or landing. Finally. there's always the option of installing a home automation system and have that report the state of everything back to some device, or incorporate algorithms to do useful things, like turn off unused lights after a certain period of time, perhaps using occupancy sensing to determine when lighting is no longer needed.

Those look like the same make as the ones I used, except mine were conventional brick size. I found that the mortar seemed to be very like white tile adhesive, and if I had to guess I'd say it was exactly the same stuff. I also found that it was essential to use the reinforcing rods. Wickes stocked these when I was looking around for some.

I've used lots of polytunnel tape over the years (mother had polytunnels at the farm). It only has a limited life, maybe 5 to 10 tears at the most. I'd not want to rely on it for something hidden within the structure of a building, TBH.

Indeed there aren't, although it does seem at times as if the rules are applied in a somewhat arbitrary and iniquitous manner. An example I've quoted here before is of a friend that has been breeding and rearing fancy chickens (the breeds that are grown for showing). She's been doing this for well over 20 years now, and managed to gain PP to site a static caravan on her small holding, after she argued (at great length, during several applications) that she needed to be close to her flock in order to shut them up at night, deal with night time predators, etc. Several times she's applied to convert her temporary caravan consent converted to consent for a small bungalow in the same place on site. She's OK if that house had an agricultural tie. She continues to be refused PP, although they do renew her consent to keep the caravan there. This seems bonkers to me, when there are other, similar, rural developments that are being granted consent, often with flimsier justification.

I'm with @ProDave on the useless design of terminals now. The older double screw terminals were way better, not just because they provided redundancy and more contact area, but also because they didn't deform the wire so badly. Gate clamps are a PITA in my view. Both because they have the ability for wires to be inserted but not clamped when the screw is tightened, but also because they often aren't very good at gripping bigger cables. I did an inadvertent experiment recently, when wiring some 25mm² tails to an isolator . I was wiring the panel on the bench, prior to fitting it in a box (just for easier access) and discovered that the 25mm² tails kept coming loose. It seems that the slightest bit of movement will tend to loosen off the clamping force, even after the screw has been torqued up to the right setting twice. It certainly makes a good case for tightly securing tails close to terminals so they cannot be wiggled to see if they are secure, as this wiggling seems enough to loosen them off slightly.

I suspect that will be the argument that's put forward to the planning officer, but if the planning officer takes a look at the trees and shrubs around the site it's not hard to work out that several mature trees were felled in order to clear a space, and that lots of young trees were all planted at around the same time. I'm not a tree expert, by any means, but it was clear to me that there was two distinct growth phases up there.