Jeremy Harris

Thanks both, I was under the misapprehension that if you used a gas safe registered trades person then that was all that was needed. I bet it's not that commonly known by potential customers that there are all the various categories, and I doubt that many check. I use a local chap (literally local, as in four doors away from me!) to service our combi every year (having suffered at the hands of the incompetent installers who fitted it - another story, about a dozen call outs to fix the thing in the first year) and I've never thought to ask to see what ticket he has. He used to be CORGI registered, and had that logo on his van when we first used him (to sort out the installation problems that the big installer couldn't fix) and when that changed to gas safe I never bothered to check again.

I agree, but was just putting forward a possible reason why someone would do work like this that's non-compliant. They are putting themselves in the firing line in terms of liability, as I understand the law around working with gas installations, not to mention possibly losing their livelihood by having their gas safe registration withdrawn. Is it possible to be gas safe registered and not hold an LPG ticket?

That is a challenge to work around! I was lucky, because I'd left plenty of time for me to do a lot of first fix work, like the plumbing, ventilation and heating systems, putting a lot of the hardware in place for the electrical first fix etc, so the only real problem I had was delaying the roofers, who were a fairly big company and able to reschedule. The scaffolders seem to be used to changing things at very short notice, so weren't a problem at all. I ended up doing some things out of the order I'd planned, because of the delay and the fairly fixed schedule the electrician had, but that just meant me moving some of my first fix work to after the electrician had finished his bit. As we had Christmas in the middle of this phase, we had a couple of weeks where no one was available anyway, during which I could do some of the catch-up work before the plasterers arrived to start boarding the house out. Even then I was right up against it, as I was still running network cable around and fitting acoustic insulation whilst the plasterers were boarding out - it was a bit of a race at times for me to get things in before they were ready to board that area out!

I agree with you, Terry, and I did much the same as you, building up sub assemblies that I could test before installation, wherever it was practical. In my case, most of that stuff was related to the borehole plumbing and things like the water softener valve set, because the manifold layout I used didn't really lend itself to being tested as stand alone modules.

If it's any consolation, I know that I held up our build for around 6 weeks, because of the drilling rig fiasco during our ground works, and that must have had a knock on effect to those in the chain ahead of and after us. I bet we're not the only ones to have held them up, either, so they have to be pretty good at changing plans on the fly and delays may well be out of their hands (as in our case).

In all probability they would just accept the paperwork, unless the building inspector happened to be familiar with good practice WRG to bottled LPG installations, which isn't very likely, I suspect. My experience was that there wasn't a great deal of detailed inspection done during any of our inspections. It seemed to me that the building inspector was more concerned with getting a feel for the competence of the people doing the work whenever he called. Only two things were actually checked during our build, and they were the drain pressure test and the compliance with Part M for the doors and entrance through to the downstairs WC. The rest was making sure all the bits of paper were on file.

A lot of this makes very good sense, Terry, but you (and I) have the time to do things this way, for our own convenience and peace of mind. Someone making a living from it has to do the job at an affordable price for the customer, and as the saying goes, time is money. The electrician I used for the house wiring was bloody good, but did think that I was going a bit OTT with some of the stuff I'd specified, and even some of the work I'd done before first fix, like fit loads of backing boards wherever fittings were going, all set to the right depth to either set the boxes in the right place or be dead flush with the rear face of the plasterboard where things like lights, pull cord switches surface mount control units etc were going to be fitted. I can understand why, as I had the time to do all this stuff in exactly the way I wanted it done, a luxury that someone making a living from it wouldn't normally have.

Looking at the photo I have, the galvanised straps around our bottles look very much like an anti-theft measure, as the hinge is padlocked closed. If it's still available, then the strap looks like a nice, neat way to secure the bottles to the wall and reduce the risk of theft. Certainly neater than chains or a cage. WRG to there being good and bad in all trades, I'd agree (and my experience with an electrician who couldn't properly fit a 20S gland that I'd supplied to a 1.5mm SWA cable I'd also supplied, leaving it with the armour barely gripped at all, backs this up). However, in this case I'm inclined to wonder whether the gas fitter may just have been unfamiliar with LPG installations. In areas with mains gas, like Terry's, I bet gas fitters don't do much, if any, bottled LPG work. I know there's a very good argument for saying that he/she should have been familiar with the need to use proper hoses, secure the cylinders from being knocked over, etc, but if he/she hadn't done a bottled LPG installation at all, or for some years, then this could just be down to unfamiliarity with bottled LPG.

Worth remembering that this is UFH going down in a refurb that, with the best will in the world, is not going to be close to PH levels! This means the slab heat loss could be significant during the heating season, because the UFH is going to have to run warmer than yours or mine, Terry, in order to give enough heat output. That may well push up the delta T between the slab and the ground to levels that are not dissimilar to the inside air and outside air. Investing in good insulation under UFH, especially in a refurb, is going to be money well spent in my view.

The blower test is a bit extreme, as it simulates you having a fairly large hole in the wall with a wind speed of just over 9m/s (a bit over 20mph, or the lower end of force 5) blowing at it. It's designed to test air leakage, not give a figure for the normal ventilation rate. So, if you have a blower test result that's around the 0.6 ACH at 50 Pa region (that's the PH upper limit) then natural ventilation without MVHR would be very much less than the blower test figure almost all of the time. Because dynamic pressure is proportional to the square of wind speed, the pressure difference at low wind speeds is a lot less than the 50 Pa that the blower test uses. A 5 mph wind speed would give a dynamic pressure of just under 3 Pa, for example, so if the air leakage was linearly proportional to pressure differential (a reasonable assumption, I think) then 0.6 ACH at 50 Pa leakage would drop to around 0.036 ACH at 3 Pa. On a fairly still day like today (here, anyway) where the wind speed outside is around 1 mph, the dynamic pressure is just under 0.1 Pa, so less than 0.2% of the pressure used for the air test and correspondingly less than 0.2% of the air leakage rate. The very low normal air leakage from getting down to PH levels of airtightness is what allows MVHR to work well, as the natural ventilation rate will be extremely low most of the time. If the MVHR was providing a ventilation rate of 0.5 ACH, say, and the house natural ventilation from leakage was around 0.036 ACH, then about 93% of the ventilation will be provided by the MVHR. In practice, the average natural ventilation rate for a house this well sealed will be a lot lower that 0.036 ACH, unless the house was in a very exposed location. If you have sealed the house well, then to all intents and purposes you can assume there is no natural ventilation and that it's all provided by the MVHR. This is a reasonable assumption because the MVHR flow rates will always significantly exceed the natural ventilation flow rates, as long as the doors and windows are closed. So, if you use a high MVHR background ventilation rate of 0.5 ACH, together with the MVHR efficiency (say 80% to allow for a few losses), then the equivalent ventilation heat loss ends up being determined by the effective cold air ventilation rate of 0.5 x 20% = 0.1 ACH .

Terry, I've dug out an old photo of our place in Scotland (sadly a real photo, rather than a digital one, and my old scanner won't work with this machine................). Looking at it, we have regulators on the bottles, connected via braided hoses to a three-way valve (I remember it being two way, but in the photo it has a centre off position). The bottles are secured to the wall with hinged, galvanised steel hoops (with "Calor" labels on, so it looks like the installer supplied and fitted them). The valve is a pretty big affair, with a flange that's screwed to the wall. It has a screw on it that looks just like the one on our gas meter, so I'm certain that's the manometer leak test point. From the position of the leak test screw, it looks like it could be used to test just the house side (with the valve in the centre off position), and the house side to each cylinder in turn (with the cylinder valves off). The rigid pipe runs down the wall and then into the house. It's hard to see the detail because it's a photo I took of the whole back of the house, at the time we bought it in 1993, and the bottles are tucked away in the corner, with a garden fence behind them. I know that all I did was fit the hob to the kitchen worktop and run the length of pipe into the house, leaving it unconnected at either end, as the builders gave me access before we'd completed the purchase to do a few jobs like this; laying flooring throughout the house and making an additional access and hardstanding alongside the garage for my small yacht to go during the winter. I thought that the builder had used his own gas fitter, but looking at the photo the prominent Calor labels suggests it was done by them, perhaps.

The usual ventilation rate is between 0.4 and 0.6 air changes per hour with MVHR, plus the MVHR heat recovery efficiency needs to be accounted for. I think that some parts of the UK have a minimum ventilation rate of 0.5 ACH, but we run our system at about 0.43 ACH and it seems to be about right. Even on full boost we can't achieve 2 ACH, I think we can get to about 1.5 to 1.6 ACH maximum on full boost. The fabric losses seem about right to me (I've not checked them) as they are in the right ball park for a low volume, high surface area to volume ratio building. The ventilation loss you've assumed is throwing your calcs out a heck of a lot, I think, especially when you factor in around 80% of more heat recovery at a more reasonable ventilation rate of around 0.5 ACH.

It depends a great deal on the circumstances. For example, around 20 years ago a developer bought a swathe of farmland outside a nearby town, that was well outside the development boundary. they paid an agricultural land price for it, at that time probably around £3k to £4k per acre or so. They rented it out as farmland and sat on it, then many years later, when the planning policy changed (with, I suspect, more than a little influence from the developer........) a large (as in several hundred houses) plan was approved. I reckon that paid around £500 per plot, so their uplift was around 100 times the purchase price, but over a fair period of time, around 15 years or so. On the other hand, my neighbours field was bought for around £20k per plot, so the uplift was only about 2.5 times the purchase price, but the developers bought it with a condition that the sale would only complete after they'd got PP. In general, the uplift from agricultural land price to building plot land price is usually around 50 to 100 times, hence the motivation for speculative land purchases around areas predicted to grow.

The Munster doors don't need lowering, they are fine WRG to Part M just fitted at slab level, as long as the floor covering is at least 10mm, IIRC. We used 12mm bamboo or travertine and this ended up pretty much level with the low-profile Munster thresholds. I'd rather the thresholds were higher, TBH, as there's only a few mm of clearance under the doors when they open and no room for a doormat (I'm going to have to cut holes in the flooring and fit recessed mats, I think).

Not really, is the simple answer, as there is a risk of induced current in the signal cables. I'd stick to the 300mm separation rule, although the SWA can be directly buried rather than go in a duct, if that makes getting the spacing a bit easier to do. The spacing can be vertical, rather than horizontal, with the power cable deeper by 300mm than the signal cable, but if doing that then make sure that the warning tape is clearly visible above the power cable. I also use contrasting sand (the local sand here is almost bright orange) over the cable and under the warning tape, so anyone that digs down gets a double warning that there's a power cable there. My personal preference is to use ducts for everything, really just because it allows for changes fairly easily, but a buried SWA power cable is going to last for many decades, so sticking it a duct is probably a bit OTT.

From what I can remember (bearing in mind that I'm going back to 1993 here......) the external LPG connection we installed and had signed off, was a manual changeover valve, fed by a fixed copper pipe, bolted to an external wall, and the valve head had the the standard gas screw-in port for the manometer for leak testing, the same as on every mains gas meter. I'm damned certain that flexible pipes with jubilee clips are not only non-compliant with the regs, but downright bloody dangerous. I went through all this with a boat years ago, getting the gas installation signed off to get a Thames licence, and had to replace a couple of (necessary on a boat) flexible hoses with ones with proper crimped fittings and the appropriate certification (some rubber hoses don't like LPG, apparently). Given that properly made-off crimped flexible hoses are relatively cheap and available from just about every LPG appliance or system supplier, and given the hazards associated with gas, I'd be inclined to get these double-checked.

TBH, I was a bit uncertain of what to do with our slab, as I hadn't thought about it until the day before the concrete pour, when the MBC lads asked me what to do at the door thresholds! There followed a bit of mild panic while I thought about their suggestion to cut a 100mm x 100mm section from the wing insulation at every door, and concluded that the effect was pretty small, given that the frame of the doors was a bigger thermal bridge. For us it worked perfectly, the door frames fitted so their outer faces were flush with the frame outer skin and the extended cills projected out about 70mm, enough to overhang the cladding base strip (which is 18mm black uPVC) by a bit over 25mm.

Yes, it does help. I have an antenna on a 6ft mast, poking over the ridge of the house. It's a directional antenna with a fair bit of gain over the sort of antenna in a mobile phone, and that just about allows me to get a pretty weak signal (1, maybe 2 bars) from the nearest base station, which is only about a mile away but over a hill. The type of repeater I have can work well in the right location; before I moved it to the new house I had it on a 12ft mast above the roof of our old house, and it gave us a pretty solid mobile signal at one end of the house. The snag is these repeaters are illegal, without a question of doubt, and there are a few tales of them being detected by the networks are your phone being shutdown, although I'm not at all convinced it's actually happened, or that the network can be sure that a repeater is being used. I've had a look at mine and it is pretty dumb, just a filter and pre-amplifier on the downlink band and a power amplifier and filter on the uplink band, with circulators to keep the signals separate at each end. As far as the network is concerned I'm pretty sure it will look just like a phone. I'd guess that the main issue is interference, or using one of these things too close to a base station and perhaps causing a problem from the relatively high effective radiated power from the directional antenna, but then most people would only get one if they were in a poor signal area.

It's a nice idea, but the planners tend to throw a spanner in the works down here. It was suggested a while ago and the developer concerned was very keen indeed, but it was vetoed by the planners on the grounds that the self-builds may not fit the new development "street scene" and that the timing of them could be subject to delay, leaving the other residents of the new development living close to an active building site.......................... A couple of years ago a developer bought a field belonging to my neighbour, subject to them getting planning consent. They did eventually get planning consent, after making a large S.106 agreement (for something the village can't actually spend the money on, so they will get it back....................) and they still haven't started work on building the 28 houses, more than 2 years after they were granted consent. 30% of the development are "affordable homes" and their argument at the planning meeting was that there was "an urgent need for affordable housing in the village". We now have Bovis putting in an application for 50 homes on another field at the edge of the village, and, guess what? They are arguing that they should be granted planning permission because there is still an urgent need for "affordable homes" in the village. I have a rough idea of what the first developer paid for the land; around £20k per plot, plus planning costs. At a guess the cheapest "affordable homes" will be around £260k, the top of the range homes at the other end of the development, 4/5 bedrooms, will be around the £550k to £700k mark.

If it's any help, we fitted an LPG hob in a new house build in Scotland. I fitted the hob and ran 10mm plastic coated copper in a continuous run from the hob connection point to the external cylinder changeover valve, but didn't terminate the pipe. The gas fitter from the building company then came in and made the connections either end, leak tested it etc and it didn't actually cost us anything, as the builder did it as a favour.

£38k per house is a bit more than the build profit most mass house builders will admit to. Most seem to reckon they work on margins of around 8% to 10%. At a guess, I'd say that the average price of a new house could be somewhere around £250k to £280k, so the Bovis profit looks to be on the high side. My guess is that they make most of their profit on land value uplift, though, rather than building houses. I've no doubt the homes are of a poor quality, that's par for the course with a great many big builders, but this story seems to be about them wanting to get cash on their books before the end of their company FY, which seems to be December for them (as it is for a fair few companies now). It looks like the applied pressure to get people to move into incomplete homes just to boost their completed sales figures for that financial year. In the light of their profits warning this seems understandable, even if it is a pretty grim way to behave.

The pub in the village we're moving to closed a few years ago, and almost certainly doesn't get a mobile signal, and when the MBC lads who built our house were staying in a pub in a nearby village they were moaning that they couldn't get either a mobile signal or wifi! The problem here is that the majority of the population live in the big conurbations, like Salisbury and the surrounding fairly large towns, and they all have pretty good coverage. Once you get out into the countryside, where, at a guess, only around 5% or so of the local population live, coverage just disappears,

That sounds like a very pragmatic way to tackle this! If you could leave the curved wall frames outside you might be able to use them as a mould to get the right curve, but I suspect you don't need to be super accurate, as there will always be a degree of flexibility to play with.

V-Cut make 12.5mm flexible plasterboard, no idea how much it costs, though. The 6mm stuff you fit as two layers, from what I remember. I can't remember who it was did this, but do recall that it looked pretty good when it was finished.

There is some interest in setting up a community service, but at the moment only from a dozen or so people, including some who'd like to work from home. It seems the majority just accept the pretty poor coverage as being the price they pay for living here. We've lived in our old house for 17 years, in a village with a population of around 500, and in that time have never had mobile coverage and have lost terrestrial TV coverage. We'll lose radio coverage too when they turn off FM in 2020. We do, by good fortune, have very good broadband, thanks to a certain military establishment just down the road that had a high bandwidth fibre put in, right along our road to the old telephone exchange less than 100m away. That's very unusual for this area, though, where most of the small rural exchanges aren't yet unbundled and aren't fibre connected.