Jeremy Harris

I agree about cost, it doesn't have to cost more to make a house more energy efficient. We had an open day at our build, when a lot of architects (about ten, all told) came for a look around. One of them was very interested in the build cost, and I gave him all of our costs. His comment was that he thought our basic, insulated, airtight and watertight, shell cost about 10% less than he'd have anticipated for a one-off build. That's born out by our costs ending up around the average for a self-build, for a house that needs very little heating. It's really as much about attention to detail with the design and construction as it is to do with using more expensive insulation. A great deal of the reduced energy use comes from designing out air permeability and thermal bridges.

We have cooling built-in to our MVHR, a Genvex Premium 1L. It can deliver about 1.5 kW of cooling via a built-in air to air heat pump, which is OK, but frankly isn't tremendously powerful, and it can very easily be over-powered by solar gain during the Spring and Autumn. I had hoped that this much cooling via the MVHR would make a significant difference, but the real issue is that MVHR delivers far too low an air flow rate to be able to shift a lot of heat out of the house. When our MVHR is running in cooling mode it has to boost to maximum air flow rate to do it, so there is a bit of noise, and even then we find that the small air con unit we fitted in the bedroom is massively more powerful when it comes to cooling the house (it's easily around 5 or 6 times more effective than the MVHR in cooling mode). In terms of cost, the added cost of opting for MVHR with an integral ASHP was high, probably an extra couple of thousand pounds or more, whereas the small air con unit I fitted last year cost around £800 or so, installed. If we were starting again I'd not bother cooling via the MVHR at all, but would have saved a lot of cash and just installed an air con unit high up in the centre of the house, as that would have been many times more effective and a lot cheaper.

I shopped around for the various parts needed from several online suppliers, including CVC. The design was pretty easy, just stick the extract terminals as far away from a room fresh air inlet as practical, and the reverse for fresh air inlet terminals. In practice we've ended up with a near-ideal arrangement in most rooms, with the air having to travel via the longest path across the room, which aids diffusion and reduces the risk of there being ventilation dead spots. There were two places where I had to compromise with terminal positioning. One was the bedrooms, where, because of the high vaulted ceilings, I couldn't easily fit terminals high up, so had to fit terminals in the low walls, but I fitted them with directional terminal vents, so the air is directed upwards, more or less along the angle of the ceiling. The other compromise was in the utility room, where I fitted the extract terminal dead centre above where the clothes drying rack is. Not ideal, as having terminals towards the centre of a room is always a compromise in terms of best air mixing, but OK, as the utility has through air movement, as there's a door from the end of it that leads to the downstairs WC, with another extract. I found that the various companies supplying semi-rigid round duct were all selling pretty much the same product, perhaps in different colours. It seems that there may well be licence deals regarding this, so the same stuff is marketed under different names (for example Domus and HB+ seem to be an identical product). There were also wide variations in plenum chamber and terminal prices, and I ended up shopping around for those, and think I used different suppliers for each. Our terminals all came from CVC, as did the terminal to semi-rigid duct fittings, the plenum manifolds came from another online supplier, as they were a lot cheaper than CVC, and the coils of semi-rigid duct came from yet another supplier (I used stuff that was branded HB+, but it was 100% compatible with Domus fittings, seals etc).

Our underfloor insulation is EPS100, but that's probably as much to do with the availability of large, thick, sheets as anything else. The actual load on it is around 6 kN/m², so just 6% of the max compressive load rating of the insulation. The reason for this low loading has a lot to do with the way that EPS compressive strength is defined, as the limit figure is for 10% compression, which would mean that a 300mm thick layer of insulation would move about 30mm when loaded to it's maximum, which would be unacceptable. In general it seems that the loading is derated to be below about 10% of the maximum allowable, in order to minimise movement.

Yes, I did. Here's a fairly simple calculation spreadsheet that may help, although I'd not get too hung up about percentages, as when you're only putting about 400 W of heat into the floor, the loss of about 32 W of it isn't really worth worrying about too much: Floor heat loss and UFH calculator.xls

The RF transmitted from a smart meter is exactly the same frequency and ERP as that from a 'phone, as they use the same network, so have to meet the same client side specification. The actual ERP will depend on the distance from the nearest cell tower, as the spec requires devices to step their ERP up and down such that the power is set to the lowest level needed in order to maintain a reliable connection. The rationale for this is primarily driven by the requirements for mobile devices, to improve battery life, but it holds true for all client side equipment, as there is a need to try to restrict interference, and having all devices use the lowest power needed for a reliable connection helps to maintain network capacity. An establishment I managed a bit over 20 years ago did a lot of research into the biological effects of RF, driven by health concerns that arose from an enquiry into why the safe exposure limit set by Russia (more accurately the former Soviet Union) was about an order of magnitude lower than the limits used widely across the Western world. This was around 1998, when people first raised concerns about mobile 'phone safety. The safe limit we use in the UK and most of Europe was based on the measured heating effect in biological organisms, whereas the limit used in Russia was based on some very small observed cellular effects on single celled organisms. The Russian researchers hadn't found any evidence to support the view that these small effects were adverse, but they nevertheless chose to adopt the precautionary principle and set a lower safe limit at the point where there were no observed cellular effects. Because of the inverse cube law relationship that governs the power per unit area relative to distance from a source, the one case we found where a mobile 'phone could just exceed the conservative field strength limit set by Russia was when it was held close to the ear. There was a region of around 30mm around that part of the skull close to the ear where the field strength could be sufficient, when a 'phone was transmitting on maximum power (very roughly equivalent to a weak received signal of about 1 bar on many displays) to exceed the Russian safe limit. Moving the 'phone just a 100mm or so away from the ear reduced the field strength to below that limit. At no time was the UK/European safe limit exceeded. If someone is worried about the RF from their 'phone, then just using it in speaker phone mode, or via earphones, completely removes the risk, as with the phone held maybe 200 to 300mm away from any sensitive area, even when in a very weak signal area, the field strength will be well below the most conservative limit. Most 'phones have their antenna near the top of the case, so holding the 'phone low down reduces the field strength at the hand by a great deal. A smart meter will usually be a very long way away (in field strength terms) from people, anything over a metre away reduces the field strength to a very low level, well below any threshold for any observed cellular changes. The maximum transmit power of a smart meter, 'phone, or other connected device is restricted to 2 W, and that maximum will rarely be reached if the device is in an urban area. Our work estimated that full power might be used about 3% of the time in urban areas, whilst in rural areas the chance of the device using full power is greater, we estimated that in sparsely populated areas of the UK a device might use full power about 50% of the time. Smart meters only connect to the network periodically, for a few seconds every 15 to 30 minutes, usually. A mobile 'phone behaves similarly when on standby, as it keeps the cell connection alive. If there is a risk from 2G/3G/4G/5G RF systems, then it will be massively greater from mobile 'phones than from smart meters, just because of that inverse cube law relationship and distance; a mobile 'phone is pretty much always going to be a great deal closer to a person than a smart meter ever will be. The field strength from other wireless devices in the house, like wifi (operates at 2.4 GHz and 5 GHz, so very similar to mobile 'phones etc) and perhaps wireless data links used to switch lights, thermostats etc (usually either 433 MHz or 868 MHz, the latter being close to the 900 MHz mobile 'phone band) probably also needs to be considered if anyone is concerned about this stuff. I'm personally not particularly bothered, although I do pretty much always use a mobile 'phone hands free, having seen just how close to the safe limit a 'phone held right against the ear can be. Having said that, we've had mobile 'phones around for 30 years now, and there has been no reported increase in the incidence of disease around people's ears, so if there was a health risk I'm pretty sure it would have shown up by now.

Those numbers fit with what I remember for our roof size, as well, as I was pretty sure we ended up putting in about double the volume that was actually needed. Our roof area is ~90m² and I seem to remember that the soakaway requirement was around 2m³, but we made it larger just because we could, and because the percolation rate was a bit variable.

For completeness, neither with the EA in England and Wales. I had to confirm that our discharge was to a watercourse that ran all year around before they would grant consent.

Only about half the time, perhaps, or maybe only on the upwind side of the house. The suction effect on the downwind side of a house seems to be very powerful, enough to cause the outward opening window seals on the house we owned in Scotland to make some very loud farting noises as they were blown open.

FWIW, I think that the calculation I did came up to be under 2m³, I only increased the size because I got a good deal on a lot of 20 Aquacells, we had a 15 tonne digger on site, and were already getting rid of hundreds of tonnes of soil, so another few tonnes was neither here nor there. Turned out to be handy, as much of the drive surface drains down into it as well. Our BCO (LABC Salisbury) wasn't the slightest bit interested in seeing any calculations, or even inspecting the soakaway.

I agree, if something like a garage has been built with PP, then any addition to it that's within the PD rules could be built under PD. There's no rule about grossing up the areas of an existing building with PP and that of an extension to it under PD, AFAIK. I went through this some years ago with a detached garage that had been built without PP, where I applied for a certificate of lawfulness, which was granted, then built an extension to the garage under PD, which was fine, as the certificate of lawfulness was considered to have the same standing as if the garage had been built with PP. In this case I only discovered that the garage had been built without consent when I sought advice about whether the extension to it came within the PD rules, it was the planners who advised as to the course of action to take to regularise things (before the days when they were chasing every bit of income they could).

It was a really big surprise to me, too, as well as being a damned nuisance! The cooling systems operate for a lot longer every year than the heating system, not something I'd have ever envisaged when we were first planning the house. I'm sure that a large part of it is due to our sheltered location, a combination of very little wind and a lot of exposure to the sun. Right now the air temperature outside (taken on the sheltered North side of the house) is just 13.5°C, yet the kitchen (stone) window cills are warm and my wife's been sat outside in the garden for the past hour or so, without a coat. Despite the cool weather and heavy rain yesterday morning, we still ended up turning the aircon on in the bedroom by late afternoon, as it was getting a bit too warm up there in the afternoon sun. I really wish we'd been able to fit external blinds/shutters, or had opted for something like Sage glass, as I'm sure either would have made a world of difference.

I'm pretty sure I just used the calculation method given in Part H 3.23 to 3.30. Wish I could find the spreadsheet I put together, as I remember pondering over how to calculate this. It's probably at least 3 PCs ago, though.

I can't seem to find the calculations we did for this, but remember that I used the chart in building regs to get the requirement, then worked from there with the roof area. I installed 20 heavy duty Aquacell drainage crates, wrapped in terram, under the drive, with a volume of about 196 litres each, so a total volume of 3,920 litres/3.92m². This was overkill, but the percolation rate here isn't that fast, as these crates drain via a narrow strip of permeable soil above the clay.

When I retired and cleared my desk I found around 2 dozen completely pointless certificates that I'd been given for attending all manner of training courses, many of which had been about as useful as giving a fish a bicycle.

Sometimes you just have to take a punt, though. We bought our plot knowing we needed to take two trees down to have a hope of being able to build on it, so were taking the risk that someone would come along and just bang a TPO on them (very quick and easy to do - seems a favoured trick by some professional protestors). We took the risk, and the day that we completed the purchase I instructed a tree chap to take both of them down, as quickly as possible, in order to try and pre-empt any objectors causing us pain and grief. TBH, if I was faced with a tree problem like this, with a non-native tree right on the boundary, I'd probably still go ahead. I think the main difference is that it would be an ex-tree before I ever mentioned it on a public forum, as it would have met with an unfortunate accident that necessitated it's removal. Reminds me of a telephone pole that was at the end of the garden of a house I lived in, and prevented me being able to take out a section of fence and get a car into the back garden. That pole developed severe rot around the base, and was reported to the GPO (as they were then). When the chaps came around to replace it they were slipped a few quid to stick the replacement a couple of feet to one side, giving me enough room to get a car in. (old battery acid poured into drilled holes just below ground level tends to cause very rapid "decay").

That's how I got a ~150kg Sunamp up the stairs on my own. Took me the best part of a day, and was damned hard work (and it slightly damaged the stairs). That was before I discovered just how very useful an electric stair climber can be.

Welcome. I can understand the issue, as I believe the safe lifting load limit is normally restricted to 25kg per person (under the Manual Handling Regs). There is a solution, though, and that's to hire an electric stair climber. These come in a wide range of sizes and can shift loads fairly easily and safely up and down stairs. Most bigger hire shops have electric stair climbers, and probably worth looking into, if only from the peace of mind one of these would give, over the risk of damage from manual lifting. This is one around the right size: https://www.speedyservices.com/71_6010-h-stair-climber-powered-310kg-swl

Running Ethernet cable might be handy, but it will need to be in a separate duct, with at least 100mm (I think) separation from the mains cable. AC coupled battery systems often need to sense both the power generated from a PV system and the power being imported and exported at the meter tails, and will often use Ethernet cable for the current transformer signals. There are some immersion diverter systems around that have a wireless connection between the sensor at the meter tails and the control box. The Apollo Gem is one that I know has a fairly good wireless range, for example.

The push seems to have been a result of lobbying that started way back before the big boom in renewable generation, and before the marked decrease in electricity consumption that has happened over the past few years. Pretty sure it was a few of the big suppliers who lobbied hard initially, and then managed to convince government to set a target. The volatility, particularly upwards in peak times, of the 24 hour buy-ahead 30 minute period wholesale market was creating significant problems in terms of setting tariffs, and the big suppliers were also being squeezed by OFGEN with caps on the maximum they could charge. The situation seems to have changed a fair bit, with peak generation capacity having grown to the point where negative pricing events are now becoming more frequent. We've had an in-house energy monitor for many years now, initially one that was given away free by one of the energy suppliers ten or twelve years ago, and since this house went live we've been using my home made energy monitor display. Having a smart meter would make zero difference to our energy use, as we've already tuned our demand as best we can. The things also won't work here (no signal) and when I was chatting to the meter reader a year or so ago he told me that he had to do exactly the same meter readings on houses with smart meters as those without, apparently there's a legal requirement that they do this. I suspect that other technologies may well prove to be more effective at ironing out the peaks and troughs of demand vs generation, distributed storage already seems to be making some contribution, with the payback time for relatively small commercial energy storage installations, particular those associated with renewable generation projects, looking to be fairly short. Controlling generation capacity in this way seems both simpler and potentially more profitable for generators, as they then have some control over when they supply energy, and can choose to reduce output (and store it) during low wholesale price periods, then supply from storage during higher wholesale price periods. Smart meters in homes can't really do anything similar, and it seems unlikely that they will make a noticeable difference to demand patterns.

Yes, that's fine, no problem at all, just a single run is all that's needed. You could go up to about 9 kW on 6mm² over 15m.

6mm² is fine. Voltage drop is the main criterion, and for 15m of 6mm² SWA the voltage drop at 4 kW is less than 1%, so well inside the acceptable limit.

My detached workshop is insulated, heated and cooled, yet building control just weren't interested, as it wasn't a habitable building. Building control did no inspections at all on the garage/workshop, as it was detached, not a habitable building and under the floor area where building regs would apply.

We opted for bamboo flooring. Unbelievably tough and very scratch resistant. I've been absolutely amazed at just how tough it is, as even when I've dropped tools on it it's never marked at all. Being pre-finished, with some sort of super-tough finish, means that it needs no additional finishing. I bonded it down using Sikabond, which has made for a very solid feeling floor. Many people assume the flooring is oak when they first see it, as the look is similar.

This is normal for a tap like this that has a fairly horizontal spout. As @ProDave says, it's just the water in the spout draining out. This isn't anywhere as noticeable on a tap with a vertical inverted U shaped spout, as they only drain the bit of the spout at the top, the vertical bit stays full of water after the tap is shut off.