Jeremy Harris

It's not clear, as the case law is old and hinges on judgements made on cases that pre-date the introduction of the Council Tax. The key point that came out back when I ran into trouble with our council snooper was that in order for council tax to be levied the property has to be valued by the VOA and also has to be in a condition whereby it can be considered to be a rateable hereditament. This hinges on a couple of bits of case law, that have defined some circumstances when a particular property could be deemed a hereditament, and the judgements are here: http://www.bailii.org/cgi-bin/markup.cgi?doc=/ew/cases/EWHC/Admin/2011/2125.html&query=rgm&method=boolean http://www.bailii.org/uk/cases/UKUT/LC/2011/RA_63_2008_Dec.html I know, beyond doubt, that not having a potable water supply to the house makes in uninhabitable, as far as the law goes surrounding it being an hereditament. There is some indication that not having a means of foul waste disposal may also render it uninhabitable, but I think this is less reliable, as there could be a counter argument that a portable toilet needs to be on site in order to comply with HS&E laws. It's possible that not having an electricity supply may also scupper the council tax bods, but again I'm not sure I'd rely on it, as there are plenty of people who live off-grid and still pay council tax. The most reliable way of keeping a house that's still under construction in a state where council tax cannot be charged would be to ensure it has no potable water supply. Our council, who were rude, belligerent, broke several laws when snooping around and were generally determined to get us to pay up, had to admit that not having potable water meant they were unable to issue a notice of intended completion, and so start the VOA process that leads to the charging of council tax. In our case, because we had a borehole, I had the water privately tested to make sure it was safe, but did not inform the environmental health people at the council and did not have the official environmental health water testing done. I will admit I did this out of spite, as the council had annoyed me by their attitude and accusations. As a consequence we had around an extra year of paying no council tax. Had the council behaved reasonably then I would have had the water tested earlier and paid the council tax earlier, but they put my back up, and this was my way at getting back at them.

This was the supplier I used for the panels I cut down for the window cills: http://www.mlpanels.com/softwood-panels/radiata-knotless-pine/ I ripped down three of their 600mm wide, 2m long, 30mm thick boards to make our cills, mainly because the thickness of our walls meant I needed cills that were around 295mm deep.

There is a general rule of thumb that pretty much removes the risk of interstitial condensation, and that is to make sure that there is a gradient in the vapour permeability of the build up of the walls and roof (or ceiling if it's a ventilated cold roof) such that the least vapour permeable layer is on the inside and the most vapour permeable layer is on the outside. Roofing sheets with pre-applied insulation are really for two main applications; well ventilated buildings, often those that are large and where the volume to surface area ratio is high (like warehouses, big DIY stores, etc) or very well sealed structures, where there is no possibility of water vapour getting into the wall/roof/ceiling from either side, or at the edges. Trying to use these materials for a small dwelling isn't a good idea, for all the reasons given. With regard to OSB and vapour permeability, @A_L makes a good point. The water resistant forms of OSB tend to be less vapour permeable than the non-water resistant types. OSB2 is fine, as it is fairy vapour permeable in thinner thicknesses (as used on external anti-racking skins), OSB3 a bit less so, as it is a bit less vapour permeable, and some specialist forms of OSB, such as ProPassiv OSB are almost vapour impermeable, and intended for use as a VCL inner skin.

I can remember buying large (perhaps around 2 1/2 litre or so) bottles of plain bleach, from the local hardware store (now sadly closed), and I agree, I thought it worked better. I think that when Domestos started marketing their bleach as "thick", implying that this was advantageous, many other manufacturers followed suit. The thickened bleach definitely doesn't seem to dissolve as easily; it just seems to run down into the water along the sides and sit there.

Things changed a fair bit, not just the shift away from SIPs, which was driven very much by the unresponsive attitude of the local builder we were original dealing with, but also the shift away from a GSHP, on the basis that it just didn't make any sense for the low heating requirement. Luckily the planners considered that swapping it for an ASHP was a Non-Material Amendment. The language used was a deliberate attempt to try and not seem too cocky; I thought that using that phrase seemed a more humble approach. Interesting to re-read that D&A and see that I only expected to get a SAP EPC of A96. When completed and assessed it actually got a SAP EPC of A107, so we managed to improve things a fair bit by changing a few details.

Here you go, £4.25 for enough to treat around 20,000 litres of water: http://www.ebay.co.uk/itm/200g-Calcium-Hypochlorite-High-Purity-Powder-bleach-Water-Disinfectant-/172864256699?hash=item283f833abb:g:gisAAOSwA3dYVF7P

I've been a very strong advocate of this for decades, as I've always been of the view that you get out of life only as much as you put in. There is a slight drawback to this; every now and again you come across someone who is suspicious of your motives, and can't believe that you're not doing it for some other reason. My personal view is that those that think like this may have been influenced by the greedy, self-centred, selfish society that was the product of a certain political leader's policies in the 1980's, but then again that might just be my own personal bias.....................

A lot of "domestic bleach" is thickened, often with salt or one of the methyl/ethyl cellulose compounds, perhaps, to make it "stick" better to thing like toilet pans. Sadly, it's hard to tell from the product label alone whether this is the case. If the bleach is just like water in consistency, and only smells of chlorine, then there's a reasonable chance that it may just be hypochlorite solution. I looked around on the local supermarket shelves for pure bleach, without success, though, when I was disinfecting our borehole. Even the "own brand" stuff contained thickeners - shaking the bottle was the easy way to tell that it was more viscous than water. In the end I bought a 5kg bottle of "pool shock" which is just pure calcium hypochlorite granules, and made up a strong bleach solution. Buying a 5kg bottle of the stuff was a ludicrous overkill, as I only needed about 5 litres of standard strong bleach solution to clean the borehole. As a consequence, I still have the best part of 5kg of the stuff sat on the shelf. That's enough to purify around 500,000 litres of water................

Only if you can buy unscented, unthickened, bleach that doesn't contain any additives to delay the breakdown of the solution. Often household bleach contains stuff that you wouldn't want in a drinking water supply, although if you hunt around you can find plain 70% hypochlorite solution bleach. It does degrade fairly quickly though, so ends up more expensive than making up your own stock solution from calcium hypochlorite.

The best bet is to buy dry powder calcium hypochlorite. Ebay is as good as anywhere else. A 200g bag will cost under a fiver and will disinfect around 20,000 litres of water. The easiest way to dose the water reasonably accurately, given that so little is needed, is to make up a stock solution, then use that to treat the tank periodically. If you add about 5g of calcium hypochlorite to 5 litres of clean water you will get a solution that will treat around 500 litres of water. If your tank holds, say, 50 litres of water, then adding half a litre of the stock solution will treat it OK. The stock solution doesn't have an infinite shelf life, and needs to be stored in a sealed bottle, in a cool dark place. It should last around 6 months or so, but is cheap enough that you can throw it out and make a new batch when it gets time expired (five litres of stock solution is only going to cost you around 12p or so). Time expired stock solution will still be active enough to use for cleaning patios etc, so needn't go to waste. Don't add too much of the stuff, as it will make the water smell and taste unpleasant. It's also best to not use the treated water for an hour or two, just to let the free chlorine come off a bit, which reduces any unpleasant taste. At this concentration it will kill around 95% or more of water-borne pathogens within about 30 minutes, good enough for making the water safe for cleaning your teeth etc. Boiling the water will drive off the remaining chlorine in the water, removing any remaining slightly unpleasant taste.

An open tank will get contaminated with bacteria and mould spores within minutes, and it's pot luck as to whether any of those contaminants find the conditions in the tank benign enough to multiply. Closed tanks, like those on boats, are a great deal safer, because they only have a small vent hole, they tend to stay cool all year around and there tends to be a lot less harmful bacteria and spores around at sea. If this tank was sealed, like a boat or caravan tank, and kept reasonably cool, then just dosing it with a small amount of hypochlorite (which is all Milton is - but a lot cheaper) every now and again will keep it sweet and safe enough for brushing teeth etc. Right now, the water in an open tank like this is about the same as the water in a toilet bowl after it's been flushed.

I think things may have changed, Peter, as the bit of 100mm PIR I used to insulate our old loft hatch definitely had a shiny aluminium foil layer, much as you describe, but the last sheets of 50mm Celotex I bought (when I was adding insulation to the old thermal store) seemed to have very thin aluminium foil on one side and what looked like silver painted paper on the other. I've no idea what particular type of Celotex it was, it was just whatever was on the shelf at the local BM. It was offcuts of this I used to make an insulated lid to go under our borehole cover, to prevent the pipes from freezing, and when I stuck aluminium foil tape to it, and then pulled it off to correct an error, it was clear that the silver layer was really just like paper.

I'm not sure there is a universal sweet spot. A big house can probably get away with less insulation than a small house, but will reap a greater benefit from reduced ventilation heat loss, as volume versus surface area plays a large part in things. In general, the smaller the house the more important insulation level is.

Energy prices for domestic consumers have been increasing for decades. The rate of change varies, and is impacted by world events, like oil shortages resulting from conflicts, but overall the price just steadily increases in the long term, no matter what governments do. This, slightly dated, blog entry has a reasonably good indication of how prices varied between 1998 and 2012: http://www.yougen.co.uk/blog-entry/2353/What+is+the+real+inflation+rate+for+energy'3F+/ There were some peaks and troughs, but overall the trend has always been upwards, and is likely to remain so. For comparison, my pay over the same period increased at a far lower rate than the average energy price increase. Not sure that's that significant, but I would guess that it's not untypical for energy prices to increase faster than pay, in the longer term.

We didn't bother with one, for two reasons. We bought a new house once, and found that the NHBC warranty wasn't worth the paper it was written on. The house leaked (flashing around the chimney installed upside down, believe it or not), we paid out for surveys to prove to NHBC that the house had been built incorrectly, yet still they refused to pay out. In the end our solicitor advised that it would be cheaper for us to just pay to get the remedial work done than try and pursue NHBC through the courts, as his experience was that they always resisted paying out and this ended up costing clients a great deal of money. The second reason is that we didn't need a mortgage on the house and hope not to have to sell it. Even if we did have to sell it, the cost of a one-off indemnity insurance policy to cover the years remaining until the house is ten years old would almost certainly be a lot cheaper than the cost of the warranty.

There are a couple of points here. First there is the cost benefit one, which is hard to pin down, because you may find that the relatively modest cost of additional insulation fitted during the build may reap a greater return through life that it appears from simple calculations. The effect of local conditions can make a marked difference to heat loss and gain, so it often isn't as straightforward as it seems to work out the benefit. We encountered just this problem, by accidentally creating an area where our build is that is warmer than the surrounding area all year around, gets a lot more solar gain that anticipated and loses a lot less heat than expected. Secondly there is the comfort factor. Having more insulation of a type that increases the decrement delay factor makes a big difference to the way the house feels. Houses with a high internal heat capacity and good insulation, plus good airtightness and decent heat recovery ventilation, tend to have a longer thermal time constant, so they heat up more slowly in very hot weather and cool down more slowly in very cold weather. This tends to improve comfort levels a lot. This latter point is not always well-understood, but there is a good article here that explains, in broad terms, how decrement delay affects comfort levels: http://www.greenspec.co.uk/building-design/decrement-delay/ Simply changing from a low decrement delay factor insulation product, like all forms of foam insulation, to one with an equivalent, or better, thermal performance, but with a higher decrement delay, can make a significant difference to the comfort level inside the house, both in winter and summer.

Well spotted. Having read the test results (thanks to @Temp for updating those on the thread running about this issue) as they came out, I will admit to being puzzled by some of the apparent anomalies. Clearly Celotex are too, having taken the steps they have. This is the brief statement from Celotex (there is more detail on their site, too):

@najem-icf. A bit of research on the appalling way that BBA certificates were issued for cladding materials would be useful. Some of of the polyethylene core aluminium cladding was certified on the basis of a desk top study assumed that it had the same flammability characteristics as ceramic tile, for example. It was never actually tested for fire resistance. To say the BBA certification system is unreliable and untrustworthy, is an understatement. Ever since the great multifoil insulation farce, I've assumed that the system was less than reliable. Since the revelations from Grenfell Tower, I'm convinced that you cannot trust any BBA certificate at all.

Both, but we only preheat the DHW with the heat pump, then boost it a bit, using either a charged Sunamp PV thermal battery, or a 12 kW thermostatic instant water heater, to get the 35 to 40 deg C preheated hot water up to 42 deg C minimum, typically around 50 to 55 deg C when the system is fully charged. The underfloor heating only needs water at around 25 deg C maximum, so the ASHP output is mixed down with a thermostatic mixer valve to lower the temperature a bit.

As we all know, following the detailed analysis of the way BBA certificates are issued, after the Grenfell Tower tragedy, often with no testing or analysis at all, just a "desk top study", you cannot trust what's in the BBA cert when it comes to defining the spec of the material, or even it's performance. I can assure you, beyond any doubt, that the 50mm Celotex PIR (not sure of the exact spec, it's left overs from a sheet I bought to insulate under our borehole cover) that at least some Celotex PIR does not have aluminium foil on the surface, but has what seems to be a silver painted or coated paper, that tears off in fibre layers, just like paper. I'll take some photos as soon as possible, and will also try some basic chemical analysis y to see how it reacts, simply to find out one way or the other what the coating really is. I've got a range of reagents here, and although I no longer have easy access to a lab to do a proper qualitative analysis, I should be able to do a few simple tests to see what happens when the coating is exposed to strong alkali or acid reagents.

Thanks, although to be fair, the site did have a very chequered planning history and the original owner had managed to upset everyone in the village, including the Parish Council, so we knew we were likely to have an uphill struggle to get planning for what we wanted to do. The Parish Council meeting where our application was heard was daunting. I'd made a scale model, to try and help them see what we were proposing, then I ended up having a hernia op on the Saturday morning, before attending the PC meeting on the Monday evening (I was struggling a bit!). The scale model of the site was the thing that swung it, as one PC councillor saw it, liked it, and pretty much forced all the others to agree to it. This was after the chairman had read out all the previous planning applications and objections, including the 14 points of objection the PC had raised for the previous application for the site..............

The main problem is that the usual default setting may have the heat pump trying to deliver flow temperatures in excess of 50 deg C, and they will frost up a lot at this sort of flow temperature when the weather hits the critical temperature and humidity region for icing, around 4 deg C or so in damp or misty weather. I found, by doing a lot of experiments, that setting the weather compensation curve such that the flow temperature never exceeds 40 deg C ensures that there is virtually no defrosting at all, and this gives a much better COP, as well as reducing wear and tear on the compressor and 4 way valve. I have mine set for a flat compensation curve, using the custom settings that the Command Unit allows. My unit is set to deliver 40 deg C flow temperature no matter what the outside air temperature is, and that seems to work extremely well for our installation.

The stuff about aluminium "foil" on PIR is just a bit of scaremongering. Go and look at a sheet of PIR. What you will find is that the silver surface is really silver paper, with a thin glass fibre scrim under some types. It is not aluminium foil, as such, or if it is it is only a few microns thick as a coating on some form of binder, and as such there is not enough of it to react in in any significant way with wet concrete, at least not to any degree worth worrying about, let alone debating to the nth degree. This afternoon I pulled a bit of scrap 50mm Celotex out and peeled off the silver layer, and I can say with absolute certainty that it is some form of "silver" coated or painted paper-like material. I'll take some photos on Monday if there is any doubt about this.

I've done one additional test since the original, and the permeability had reduced a by about a third from the original test figure, but that improvement was largely down to me adjusting the French windows and squirting some thick silicone into the centre of the lock barrels, as all three were leaking air through the keyhole like mad on the negative pressure test. MBC guarantee that every build will meet or exceed 0.6 ACH, and there's a hefty final payment (20% in our case) that isn't paid until the air test result comes in under this figure. AFAIK, every build passes first time, as they've got an inherently good build system, in terms of airtightness, high decrement delay insulation and absence of thermal bridging. The combination of their passive slab and modified Larsen truss "twin wall" structure pretty much guarantees no thermal bridging, as long as there are no unusual design features that get in the way of this. The airtightness won't degrade, I'm sure, as 99% of the fabric airtightness comes from the thick layer of highly compressed cellulose insulation, blown in under pressure, which pretty much guarantees the long term airtightness of the frame, as well as having a pretty good decrement delay factor. The "airtightness" tape used to seal the joins in the internal vapour control skin isn't there to enhance the airtightness, it's just there to ensure that the internal vapour permeability is very much lower than that on the OSB outer skin (the inner skin is a vapour impermeable board). The only significant cause for airtightness degradation is likely to be from the doors and windows, where some adjustments are bound to be required through life to endure the seals remain tight after a period of use.

To be honest, I can't see how the silver painted paper covering that's on one side of Celotex PIR can in any way impede vapour or gas movement. The stuff is clearly permeable, as you can see if you tear a bit off. Also, the edges of the foam panels aren't sealed. The final nail in the coffin for the prevention of off gassing idea is that if the foam was still off gassing and if the silver layer was impermeable, then the pressure build up would just blow the surface layer off and cause it to unbond.