Jeremy Harris

My one and only attempt to claim against NHBC failed, even though I had irrefutable proof that the water ingress and subsequent damage was caused by the builder fitting the chimney flashing upside down (i.e overlaps in the lead pointing upwards................). After several months of battling with NHBC, paying for an independent surveyor and incurring a few hundred pounds in lawyers fees, my lawyers advice was to cut our losses and pay to fix the problem ourselves, as in his experience NHBC would do damned near anything to delay paying out until owners got fed up of waiting.

I've been wading through the claim and counter-claim of all the financial predictions and frankly I don't trust any of them. The assumption by the "remain" lot seems to be that we will try our damnedest after a decision to leave to drive our own economy into the ground, which seems absurd. On the other hand, the "leave" lot are making assumptions about savings from not contributing to the EU that seem bonkers, so I don't trust their numbers either. What I'm pretty sure of is that whichever way the decision goes, there will be a tremendous amount of effort put in to reducing the financial impact, and given our ability to be "creative" when it comes to dealing with the nation's finances I have no doubt whatsoever that the predictions being made now will turn out to be complete and utter hogwash. As mentioned in another thread, I am pretty sure that this vote won't be decided on the basis of any rational analysis by voters of the relative financial benefits or costs, it will almost certainly come down to personal, probably single issue, reasons for voting in or out.

They chased me up to see if I was going to buy, around three months or so after sending me the quote, and I told them openly that I'd bought the same unit from Denmark for a very much lower price than they had quoted. I'm not sure how much difference it will make, but I've been told that it reduces the flow resistance a great deal when fitted (because it completely replaces the heat exchanger unit), as well as decreasing the temperature into the cooling part a bit, so it seems to be worth the relatively modest cost, even if it just increases the air flow rates in summer.

Sometimes questions are raised as to whether it's worth increasing insulation levels and often there seems to be confusion as to what the "ideal" level of insulation is, or even what a "good" or "reasonable" level of insulation might be. I'm not sure whether or not the non-linear impact of improving insulation, in terms of the effect on the heating requirement, and hence running cost during cold weather, is widely understood. I've heard comments like "it's not worth improving the insulation from 0.16 W/m2.K to 0.12 W/m2.K because it would be 30% more expensive and only reduce the heat loss by 25%". Most of the time this is incorrect, because homes have heat sources all year around, from the occupants, incidental heating from appliances, solar gain and even pets (a medium sized dog is probably a four-legged 40 - 50W heater). So, I thought a really simple example might help some gain a better understanding of this non-linearity, and illustrate better why some are so evangelical about trying to improve insulation levels (and reduce ventilation heat loss, too, but I'll get to that another time). Let's build a pretend house, that for simplicity has no doors or windows and is a rectangular single storey box with a flat roof. For simplicity we'll assume it's on raised piles, with an air space underneath, just so we can use the same insulation level on all six sides and to make the sums simple. All I'm doing here is making a comparison, so this is a valid way of illustrating this effect. In our rectangular box house we have an average of 100W of incidental heating, coming from things like internet kit, a PC, a cordless phone base station, a TV, a phone charger, a few lights and a handful of intermittently used kitchen appliances. This is a pretty low figure - I struggle to keep our house background load below about 200W, without any lights on. The box houses two adults, giving out around 80 - 100W each and a dog, so lets say there is 220 W of heating coming from the occupants. The box also has a heating system that can deliver whatever power is needed to maintain a temperature of 20 deg C inside, and its night time, so there's no solar heating of the walls. Outside it's 5 deg C, a chilly winters night. This rectangular box is 10m long x 10m wide x 2.5m high inside, so has a total wall, floor and roof area of 300m2 and an internal floor area of 100m2, so fairly average in size (a bit bigger than our current 3 bed bungalow). So, we have a temperature difference between the inside and outside of 15 deg C (20 deg C - 5 deg C), an internal surface area of 300m2 and a constant incidental heating level of 320 W (220 W from two adults and dog, 100 W from electrical appliances and lights). First, lets see how much heat we need to put into this box from the heating system, if we have U values for the walls, floor and roof of 0.2 W/m2.K (K is degrees Kelvin, the same units as degrees Centigrade when only temperature difference is being compared): The total heat loss power, in Watts, can be calculated from the U value, the area and the temperature difference, so for this first example we get 300m2 area x 15 deg C temperature difference x 0.2 W/m2.K U value = 900 W. There is 320 W of heat coming from the occupants etc, so the heating system would need to deliver 900 - 320 = 580 W in order to keep the house at 20 deg C under these conditions. If this were by direct electric heating, then the heating cost would be about £2.09 per 24 hours. Next, let's see how much heat we need to put into this box from the heating system, if we have U values for the walls, floor and roof of 0.1 W/m2.K , in other words, we've made the insulation twice as "good", so might think we've halved the heating cost: The total heat loss power is now 300m2 x 15 deg C temperature difference x 0.1 W/m2.K U value = 450 W. This is what we'd expect, double the insulation effectiveness and halve the heat loss. However, when we now take away the incidental heat gain from the occupants, etc, of 320 W, the heating system needs to deliver 450 - 320 = 130 W in order to keep the house at 20 deg C under these conditions. If this were by direct electric heating, then the cost would be about £0.47 per 24 hours. So, by doubling the insulation level we've decreased the heating cost by about 78%, not the 50% that might have been expected. This is a very simplistic example, but it does illustrate why doubling up in insulation can give a far greater benefit than might be expected. It also shows why, when you improve the level of insulation you can reduce the heating requirement down to such a low level that for a lot of the time you don't need any heating. In that last example, turning on a few extra lights could heat this imaginary box home to a comfortable temperature on a cold night, whereas with only half the insulation it needs something that delivers 446% more heat.

The price I got (both times) was a written quote, I don't think they give prices unless you ask for a quote, do they? If they have seen sense and brought their prices more in line with other suppliers then that's a good thing, but then again it's still a fair bit cheaper for me to buy the Sommerbox from Denmark, even with the expensive shipping.

If I'm honest, I found the first purchase from outside the UK a bit worrying, but that experience was very positive. The supplier really wanted to do business, was very efficient and spoke and wrote perfect English (it was a Dutch company). The next purchase from Europe was the MVHR, where my experience was very similar; excellent customer service and no language problems. We went on to buy some appliances from Germany, and once again found the standard of service to be better than that of many UK suppliers. Overall I'd strongly suggest shopping around, at least within Europe, as it is, if anything, a better experience than trying to deal with some UK suppliers. I lost count of the number of suppliers who just failed to get back to us with quotes, all of them from the UK. My limited experience has been that the European suppliers have been far more helpful. It's not just house-related stuff, either. Many years ago I wanted a bike rack to fit the first Toyota Prius I bought, in 2005. Toyota Netherlands had one listed, but Toyota GB could not (or would not) supply it, even though it was actually made in the UK and approved by Toyota! The UK manufacturer couldn't sell it directly, as they only made the product for sale to Toyota. I telephoned a random Toyota dealer in the Netherlands and asked if they could sell me one and ship it to the UK. They went out of their way to both get the rack and arrange shipping to the UK, including getting the fitting instructions translated into English. Perhaps if more people shopped around and complained about the generally poor service from some UK suppliers things might change, or is that just me being overly optimistic?

200mm mineral wool between the rafters is cheap, but won't get you to 0.16 W/m2.K without some additional insulation inside or outside to both mitigate cold bridging through the rafters and to give the needed level of insulation. It's a reasonably good choice for a roof, though, as it has a medium length decrement delay (better than foams and other very low heat capacity insulation) and it is easier to fit than cutting foam to fit and then going around filling all the gaps with expanding foam. I don't have my U value calculator here on this machine, but would guess that you'd get between 0.18 and 0.19 W/m2.K with just the mineral wool, so you'd need to add a layer of higher performance rigid foam insulation either over the rafters or under them. If the latter, then you can possibly use a foil-coated board and tape the joints to also give you the necessary VCL internally.

It depends a fair bit on the ground work needed, but double the price of an ASHP seems about right unless you're lucky enough to have a big lake or perhaps a stream flowing through your garden, where you can just drop in a collector mat.

There could be valid reasons, yes, except for the Euro, as Denmark is outside the Eurozone, so prices are in Danish Krone. These are the same two Genvex suppliers that I've compared before. In the previous case, for the purchase of the unit in December 2013, the variation was a lot greater: UK supplier - £8,230, including delivery and VAT, £6,858.33 total, ex-VAT Danish supplier - £5,044.16 inc delivery and VAT, £4,035.33 total, ex-VAT In the case of the purchase of the whole unit, the UK delivery charge was £248 + VAT, the Danish delivery charge was £112.10 + VAT, which is just bonkers - how can it cost more than double to deliver it within the UK than it did to deliver it from Denmark?

Here's a link to the story: http://www.greenbuildingadvisor.com/blogs/dept/musings/belgian-passivhaus-rendered-uninhabitable-bad-indoor-air

There are several threads here discussing buying from elsewhere in Europe, because you get better value, and, in some cases, a greater choice or better quality products. I've just been looking at the price for a part for our MVHR, a "Sommerbox" that is a 5 minute slot-in replacement for the heat exchanger to gain better cooling in the summer. I got hold of the part number from Genvex (who are always very helpful, BTW) but Genvex don't sell direct so I asked two of their suppliers for prices. Here are the prices for comparison: UK supplier - unit price £174.00 inc VAT for the part, plus £30.00 inc VAT for delivery, giving a total of £204.00 inc VAT Danish supplier - unit price £128.82 inc, VAT for the part plus £62.48 inc VAT for delivery, giving a total of £191.40 inc VAT Now this was a VAT reclaimable item (I think), so the ex VAT prices including delivery would be: UK supplier - total price = £170.00 Danish supplier - total price = £153.12 Looking at just the unit price, ex-VAT, as the Danish supplier has to charge more for delivery to the UK, whereas the UK supplier presumably gets better rates for bulk shipment, then the prices are: UK supplier - part only price, ex-VAT = £145.00 Danish supplier - part only price, ex-VAT = £103.06 Given that both the UK and the Danish supplier are authorised Genvex dealers, and so are almost certainly getting the same sort of price from Genvex, what's the justification for the UK unit price being 40% higher than the Danish supplier price? My understanding is that the cost of living, doing business etc in Denmark is similar to the UK, may even be a bit higher, as their VAT rate is 25%, rather than our 20%. The only conclusion I can reach is that the UK supplier is upping the price because they can, which is most probably because people aren't shopping around to get a better price.

I looked at earth pipes, but the cost (and a few horror stories, including the infamous one that made the house uninhabitable) put me off. The payback time was going to to be far longer than my lifespan, too. Knowing what I've learned now, I'd keep things as simple as you possibly can, and accept that you might have to use small amounts of direct electricity to provide boost heat for hot water. The cost of this is small, and so not really worth worrying too much about. For example, if you have an ASHP that works at an average year-round, COP of 3, delivering water at 40 deg C (quite probable, if set up and sized correctly), you want DHW at 45 deg C and your incoming mains water is at 7 deg C, then you get about 85% of your hot water at 1/3rd of the electricity unit price and 15% at full price. Another way of looking at it is to pretend that the boost heater lowers the average COP. For the above conditions, the average COP would be lowered from 3 to about 2.55 just for the hot water delivery, the COP for heating/cooling would still be around 3. If you compare this method of providing hot water with, say, an electric shower, then a 10 kW electric shower for 10 minutes probably costs around 25p, the same shower using an ASHP and boost heater would cost about 9.8p.

All I can say is that I did pretty much exactly what Crofter did. It saved money, but there was a significant investment in time, studying past planning applications and reading all the planning policy and guidance . The latter was the hardest bit, as there were loads of cross references to other documents, so I had to keep changing to a different document part way through a sentence in order to understand it. When looking at applications on line, look at who submitted it. Around here there is one planning consultant/architectural technician who seems to get almost all his applications through at the first attempt. If I was looking to use a planning consultant he's the chap I'd choose. The same may well be true in other areas, too.

That's a more eloquent working through of my thinking when I very deliberately chose the provocative original thread title, ST. The challenge, as always, is how to clearly convey concepts that may be a bit difficult for some to understand (primarily those without a background in physics in this case) in a way that most can wrap their head around. BTW, there are still things going on to look at how the screen colours might be changed - from what I can gather it may not be particularly easy and needs some themes purchased and then set up so they are user-selectable.

When I was looking around, I couldn't find any full-flow three way ball valves, and looking at how they have to be constructed internally in order to work, I doubt that there are any. My preference would be to always use two way valves, but that's largely driven by a prejudice of three way valves borne out of having had several fail on different heating systems over the years (every house we've ever had with a three way valve has had a valve failure - maybe we've just been unlucky!). Is there any way you can reduce the number of motorised valves needed? I only have two, one on the return from the UFH manifold, to isolate it when there is no call for heating and one on the flow to the buffer tank/preheat to isolate that whenever there is a call for cooling. I have the absolute minimum number of valves in the whole system, and only fitted isolating valves where it was essential, so there are none at all anywhere in the pipework to the buffer tank, or even on the heat pump flow and return, as the volume that flows from the primary circuit drain is so low that I can catch it all in a large bucket. The UFH pipes remain full of antifreeze when the heat pump is drained down and so the volume is just that in the pipes and in the buffer tank coil.

I apologise for the way I came across. All I can say is that I received a fair bit of what can only be described as "hate mail" when Ebuild closed, because someone was spreading a false rumour that I was somehow responsible for it's closure (I was not, in any way shape or form, but some don't let the truth get in the way of an excuse to let rip). As a consequence I know that I'm taking things here more personally than I should, at the moment. I'm trying not to, but frankly it's not easy when you've been vilified by people you've never met, for something that's not your fault. The tone is a problem, you're right, and I think it arises from telling the same tale over and over again. In this case the original material, and many of the other versions, was roundly condemned as not performing as advertised many years ago, and some of us were involved in very long discussions about it, on the GBF and on Ebuild. The manufacturers gained a pretty poor reputation for misrepresentation, had approvals withdrawn because they were based on false data, in effect, and had to change adverts. It was such a scandal that a letter went out to all building inspectors warning them of some of the shortcomings and that some claims that the material could be used in thin layers and be compliant with Part L1A were not true. It comes down to trust and reputation, and when manufacturers have repeatedly marketed a product with misleading claims then personally I would mistrust any claim they make about any product. This particular thick insulation fleece product, that happens to have foil layers, is a mid-range performance insulation, if the data given is accurate, and it does seem as if this manufacturer has taken heed of the condemnation they've had from some authorities in the past and made an effort to produce a better performing, and very much thicker, product. By the manufacturers own certification data it's performance is significantly worse than high performance sheet insulation, like PIR or PUR foam, but it is a bit better as an insulator than mineral wool, and that may well make it a reasonable choice for some applications. It's very low decrement delay means it really needs to be used with a high heat capacity layer, but then that's also true of PIR or PUR foam. My concern is whether or not the manufacturers data can now be trusted, given their track record. Maybe it can, maybe it can't; people need to look at the long history and make up their own mind. I think those of us who've been around a fair time and done a bit of research into how different materials perform do need to make a greater effort to not allow our frustration at the same topic coming up yet again show, as although it's a repeat event for us, it is often the first time the person raising the issue has come across it. This message has been noted, not just by me, and I'll certainly try to tone things down when one of these relatively frequently raised topics comes up in future.

I was temporarily co-opted on to a a working group set up by three adjacent parish councils, that was set up to deal with a big planning application to turn Boscombe Down airfield into a commercial night air freight airport (it has only ever really operated daylight hours, and then fairly infrequently). One consequence of this was that I ended up on the planning committee, and one application sticks in my mind. It was a local farmer, who had purchased a new forage harvester and wanted planning consent to close his existing farm entrance and create a new one 50 yards up the road, that was both wider and a lot safer, as it was on a straight stretch of road rather than on a bend. The application also included the relocation of a public footpath, that ran up the existing drive entrance. I had read the application before the meeting, could see no reason not to recommend approval, so said so. The proposal would improve road safety, allow the farmer to get his new machinery in and out more easily and actually made the footpath align better with one on the other side of the road. We had one, very vociferous, objector on the committee. Not knowing him at all, I asked why, given all the benefits the proposal had, he was objecting. It turned out that he'd been (quite rightly) told off by the farmer for walking across his land with his dog off a lead (it's a mixed farm, arable and sheep). This was, apparently, a valid reason for objecting to a perfectly acceptable planning application.....................

If you take the time to analyse what happened on ebuild over the years (and I joined that forum in 2007, so do have a pretty good grasp on how it evolved) then there is a clear trend. By 2010/11 ebuild was dead, there were virtually no posts being made and perhaps 5 or 6 active members. Then, around 3 or 4 years ago, another forum had an upset, and a few members from there started posting on ebuild. From that point on ebuild started to grow and become busier, although that growth was slow. The curious thing is that the interest of members that joined after around 2012 did change. More people seemed interested in building lower energy consumption self-builds, or renovating or restoring existing homes to better standards. No one dictated this, no one made it happen by censoring out posts that didn't follow this general trend, it just developed naturally. Personally I think a large part of that change was because people who joined that forum wanted to build themselves better homes, or they were interested in improving the homes they have. No one person controls, or even influences, the direction a forum takes, unless it's one of the few forums that are heavily moderated to try and maintain a particular view. Ebuild developed the way it did because that's the way the members shaped it. The same will apply here, and it's already clear that this forum is different from ebuild in many ways. NSS, if you happen to dislike me for some reason there isn't a thing I can do about it, other than feel regret. I'd rather you just came out in the open and told me what your gripe is with me, because since this forum went live I've very deliberately taken a back seat and not done a single moderation task. The direction this forum takes has not, and will not, be influenced by me, any more than it will be influenced by you, or any other member. I'm at a complete loss to understand why you're seemingly so angry or upset. You've not been criticised, made fun of, insulted, or belittled, as far as I can see, and if you had then I am sure that one or other of the moderators would have stepped in to put things straight. If you feel you have, then point out the posts or parts of posts concerned, so they can be reviewed. I'd not want to be part of any community where someone felt ostracised just for contributing fair comment.

A quick look through the posts made in the few weeks since this forum came into existence shows no evidence at all to support your view. The majority of posts have been practical enquiries or advice, with not a single post I can find "demanding a quantum leap to the Holy Grail" and none "scoffing at anything less". If you can prove otherwise, and that there is lack of balance here, then please highlight the specific post numbers to prove that your assertion is valid. Sure I personally have a low tolerance for inaccuracy and downright misleading information being propagated by those who should know better. I also happen to believe (along with a fairly large body of other people, including the AECB), that our building regs are both pretty poor and that, far more importantly, there is a lack of diligence in enforcing them. However, I'm just one of a 150 or more members; some share views similar to mine, some don't. Frankly it would worry me if things were otherwise.

I think the problem is that they have fooled a lot of people, including building control bodies and even Grand Designs, most probably because people like to believe that there is a "wonder product" that defies the laws of physics. I can still clearly remember that part of the programme where Kevin McCloud demonstrated that around 20mm of this "magic" insulation was equivalent to around 200mm of "ordinary" insulation. As a (now retired) scientist it immediately got me searching for data on the stuff to see what on earth it was. IIRC, the house that was being built in that programme was the infamous "eco house" that managed to get a SAP 2005 EPC of Band F 26 (I jest not, I have a copy of the as-designed SAP here in front of me!).

Our ASHP, like the majority (probably all) inverter controlled units goes into reverse to defrost, so goes into cooling mode, which heats up the external heat exchanger to 40 to 45 deg C or so, very quickly. When it does this, it draws heat from the buffer tank or UFH and pumps back cold water at around 8 deg C to either/both. A single defrost cycle can drop the temperature of our 70 litre buffer from around 35 to 40 deg C to about 15 deg C................... It does defrost fairly quickly, but the cycle still takes around ten minutes, as it has to switch to cooling mode, pause while the 4 way valve operates, start off slowly and then ramp up to full power, presumably so that the thermal stresses of pumping refrigerant at around 45 deg C into a heat exchanger that's probably at around -5 to -10 deg C, and covered in ice, is minimised. It then has to reverse back again when it's defrosted and repeat the process of switching the 4 way valve back and ramping the power back up to maximum in order to try and re-heat the buffer tank/UFH that it's been actively cooling whilst defrosting.

Thanks ADLIan, I was beginning to think it was just me that had read much of the saga and formed a strong opinion as to both the performance and marketing strategy of this stuff! My view is that all manufacturers, of any product, need to show to me that they have always been open and honest about their products. If a manufacturer has been deceptive (and that's fair here, as it was proven and claims had to be withdrawn) then I'd not trust them again, simply because I could never be sure that there wasn't still an element of stretching the truth when it comes to providing performance data. When I first started looking at this stuff several years ago (after that GD programme) I was a bit surprised to find that hard data on the thermal performance just wasn't available. There were lots of claims, including the one claiming the ludicrous lambda value for one multifoil product, and it was damned hard to get hold of independently validated test data. When I did, I was more than a bit shocked at the way that the relatively simple laws of physics that govern heat transmission were being re-written in the advertising material from some companies in order to make certain products look far, far better than they really were. It's interesting to see how this particular company has moved away from the thin multifoils (which were useless) and shifted towards a conventional fleece or synthetic fibre/wool insulation that happens to have some foil layers in it to differentiate it from other similar products.

Openreach have, according to my local engineer, changed their policy. The originally allowed cables direct in to the house to the master socket. They then changed this for new builds and insisted that a BT66A weatherproof box be fitted to an external wall and they would terminate the incoming cable there. This rule was in place when we started, so I fitted a BT66A to our meter fence, with grey 56mm ducts and hockey sticks running from there out to the new cast iron box by the new pole and under our slab and into the house (to avoid messing up the airtightness and vapour barrier by going through the wall) . I ran a length of gel cable through the duct from the house to the BT66A outside and then sealed the inside of the duct up to maintain airtightness. When the Openreach chap came to connect he said the rules had changed again and I could have run the length of gel cable through a single duct and coiled it up at the base of the pole....................................

They seem clever enough to try and do this, or at least some are. I've noticed ours modulate the output down, then back up again, for no apparent reason, and it seems to do it when it's wet and cool. It has an external temperature and humidity sensor fitted to control defrost cycling, so I suspect it may well just reduce output initially as a way of seeing if that's enough to get the primary circuit temperature differentials looking better and only if that doesn't work does it turn off and run in reverse to defrost. It would be nice to know what these things are really doing, rather than have to guess, because it seems clear that the inverter controlled units are pretty clever at managing their own performance, within the limits set by the user.

We bought a house that had been a self-build with no warranty. I suspect the seller, who worked for a building company as a brickie, was a "serial self-builder", as he was in his late twenties and this was, apparently, his second self-build. Anyway, the lack of a warranty was no problem at all. Our lawyer raised it and the solution that kept our lender happy was an indemnity policy, which the seller paid for. When we sold the house 5 years later (when it was 7 years old) we had no problem either. Our buyer's lender just accepted the indemnity. We've talked over the warranty thing and our decision is that if one of us falls off this mortal coil before the other, then the remaining partner won't sell. It's really because we've both put a great deal of emotional effort into it, so neither would want to sell in the event of the demise of the other. I know it does seem commonplace for the remaining partner to sell up following a bereavement (both my mother and my mother in law sold up within a year) there's something very different about a self-build and the sense of ownership. We have a neighbour (two doors up from the new place, about 100m up the lane in practice) and she and her late husband (who was an architect) built their house. She still lives there today, on her own, and is proud of the house they built together.