Jeremy Harris

There's one of those turntables just down the road from me. It was mandated by the standard highways condition they seem to stick on every application around here, saying that vehicles must be able to drive off and on to the highway in forward gear. A hammer head drive (which is what we've done, as in the link from Dave above) seems to be the standard solution where there's space, but the majority of the time it seems that in practice the turning area is used as a parking area, defeating the point of the planning condition!

The main issue is getting the vapour permeability right, so that the gradation from least vapour permeable to most vapour permeable goes from inside to outside. The concern I'd have with using an external airtightness barrier is that a builder may then neglect to ensure that the vapour control layer (VCL) on the inside is as vapour tight as it needs to be, as an air test won't show failings in the VCL if something like this is used externally. That alone could be a recipe for medium to long term structural failure if the builder doesn't make sure the VCL is sealed better than the Wraptite layer, and also raises the question as to what purpose an additional air tight layer has when there has to be a VCL anyway.

I too would be inclined to sign it, although I frankly doubt that it would carry much weight if there were any damage or accident, laws with a far higher precedence would undoubtedly subsume anything that was written on a note crafted and signed without any form of legal input. If the agreement had been drawn up and witnessed by a notary, then it might possibly carry a little more weight, but in general I'm of the view that unofficial documents like this rarely have any legal standing, they are often just a comfort blanket for the person that writes them. I can give an example from personal experience, giving evidence on behalf of an insurer. A gentleman was in the habit of giving friends a ride in his own aircraft, at no charge, just for the experience. He did not hold a commercial pilots licence, just an ordinary private pilots licence, but he was in the habit of asking his passengers to sign a disclaimer, saying they were flying with him knowing that he was not a commercial pilot and would not hold him liable in the event of an accident (this was a common practice, the bits of paper were often called "blood chits"). He was insured to carry passengers, and his actions were entirely lawful, as he made no charge for these flights. One day he took off with a friend from his home airfield, and decided to land on a strip of grass he'd used before, near to where his friend lived. After lunch at a nearby pub (the pilot didn't drink alcohol) he took off, but hadn't properly assessed the wind conditions, and crashed from a height of around 100ft into a car park. Both he and his passenger were badly injured. The passenger sued the pilot, claiming that the pilot was at fault for having failed to properly assess the take off conditions from the grass strip. I went and looked at the grass strip, spoke to the instructor who had trained the pilot and then gave evidence that, in my view, the pilot was negligent, in that the wind conditions on that day made the probability of the aircraft being unable to climb at a rate fast enough to clear a row of trees highly likely. The pilot tried to claim that the "blood chit" signed by the passenger absolved him of responsibility, but the court threw that out. It was not even entered into evidence. The pilot was found liable and the case was then settled out of court.

Yes, that seems to follow the guidance for the current building regs I looked at earlier, although that guidance states "internal envelope", most probably because the majority of houses will have the VCL as the airtightness barrier, and this has to be on the inside (or very close to the inside) of the envelope. The odd thing is that my air test certificate gives two figures, the air leakage in PassivHaus terminology, using the stated house internal volume (0.43 ACH @ 50 Pa) and also the UK Part L1a figure of 1.22 m³/m²/hr @ 50 Pa, with the only area stated on the certificate being the gross internal floor area. It makes me wonder if the air test certificate is in error, as the gross internal envelope area is greater than the floor area. I'd just assumed that the data on the air test certificate defined the measurement, as the version of Part L1a I was working to (2010) didn't specifically mention the area used in the definition. Using the Part L1a 2013 definition, and taking the internal VCL as the airtightness layer (which it is), then the envelope area comes out at 230m², making the measured air permeability (using the measured leakage rate of 166m³/hr @ 50 Pa from the average of the two tests) 1.38m³/m²/hr @ 50 Pa, a bit worse than stated on the certificate, but not enough to lose any sleep over, thankfully!

According to my air test chit, it's internal floor area. Has Part L changed recently? Edited to add: It seems to. It now gives a limiting value of not more than 5m3/m2/hr at 50 Pa internal envelope area for a house with MVHR, limit is 7m3/m2/hr at 50 Pa for a naturally ventilated house. I've edited the earlier posts to show the error I made.

So, with a lot of guesstimating, this house could be around 1000m3 in volume. If the airtightness comes out as 1.7m3/m2/hr, then in terms of ACH it's around 2 ACH. Definitely into the region where MVHR will save a significant amount of energy, so worth doing, I'd have thought. Edited to add: Disregard these numbers, they are wrong. Part L1a 2013 now stipulates a limit of 5m3/m2/hr at 50 Pa, based on internal envelope area, as the limiting air leakage for a house with MVHR.

The "1.7" is probably the oddball building regs way of describing airtightness (it's unique to building regs, they invented a new system, rather than use ACH like every other country on the planet.........). As such it relates to floor area, rather than house air volume (yes, it is bizarre). This means it's probably 1.7m3/m2/hr at 50 Pa. Without knowing the house volume and floor area it's not possible to directly relate this to the more normal ACH. The chances are that 1.7m3/m2/hr is probably a bit better than the threshold where MVHR starts to bring significant benefits, in terms of energy saving. A general rule of thumb is that an airtightness of around 3 ACH @ 50 Pa is about the point where MVHR starts to work well in terms of energy saving, but it will still give a very useful improvement in air quality at poorer air tightness levels than this, it will just probably never pay for itself in terms of energy saving through life. Arguably the same could be said about our active MVHR, but I was prepared to pay the extra to get comfort cooling in hot weather.

Looks good, and they do a pack that's the right size, 6m x 4m. The thing to think about is whether I want to spend £350 on the workshop floor - I could buy some nice tools for that much money................

The Costco stuff seems to be about 2.5mm thick, I think. The mats range from around 4mm to 12mm depending on make and material (the foam ones are the thickest). The workshops in places where I've worked were always just painted, often re-painted every few years.

Thanks for the tip about the reviews, it doesn't look as if it is as good as it's made out to be. I'll keep looking over the weekend and see if I can find anything else, if not I'll just paint the floor as I've done before, and maybe get a couple of mats to lay down where the benches and machine tools are.

Thanks very much, that looks to be just the job.

My understanding is that it runs the pump for 30 minutes on, 15 minutes off, from what I've been able to glean from various sources. This seems to be about right, as the 15 minute rest pauses are enough to save a bit of pump power and wear and tear, yet not not long enough to allow sludge to settle out and compact around the air injection holes.

Thanks, I'm definitely veering towards mats or vinyl, despite the additional cost, just because I feel it might be worth it to be a bit more comfortable.

Thanks for the ideas so far. The interlocking tiles seem to vary a heck of a lot in price, and I'm not at all sure what the major difference is between the expensive ones and the cheap ones. Whatever I fit has to be able to take some pretty hefty loads. The pillar drill is a massive cast iron one, built around WWII I think (it originally had a big rotary switch before I added a no-volt contactor), so that puts a fair pressure on the floor. I could possibly paint around the edges, where the fixed heavy stuff will go, then use matting or interlocking tiles in the middle bit I suspect that metal swarf will get embedded in carpet tiles pretty easily, and that's also my concern with the foam tiles. I'll have to have a look around to see if there's anything like wide, heavy duty, vinyl. If I can get it in a 4m width, so I can have a joint free run, then that would be even better.

I'm in the final stage of clearing all the building stuff out of the garage/workshop, ready to paint the walls and ceiling and do something with the smooth concrete floor. The concrete was power floated, so has a pretty good smooth finish, but the garage will be used primarily as a workshop, with a couple of milling machines, a floor standing pillar drill, lathe, bandsaw, mitre saw etc, plus room for building things, like boats and motorcycles. I was planning to just prime and paint the floor, but I'm now in two minds as to whether to lay rubber tiles or mats instead. It needs to be a light'ish colour, as the lighting is predominately artificial, and without having given it much thought I was just going to apply two or three coats of Leyland floor paint (used it before and it's reasonably tough). The area is around 24m2 (it's just under 4m x 6m internally) and I don't want to spend a small fortune on it, as it's only a workshop. Having said that, there are a lot of claims that standing on rubber flooring is more comfortable, and that's quite appealing as I get older! The flip side is that I'm not sure how the rubber stuff would cope with metal swarf. If I did opt for laying matting or some form of rubber tiles, then I'd probably just seal the concrete with PVA to keep the dust down. Some of the fairly heavy tools are on castors, like the metal cutting bandsaw and the compressor, so I can wheel them out of the way when they aren't in use, and I'm not sure how well rubber tiles or matting will take rolling loads, which is another potential snag. Has anyone any experience of garage/workshop flooring on a fairly tight budget, please?

I used Osmo oil, very impressed with it, it seems to give a nice tough finish, too. Pity it isn't a bit cheaper, but overall I think it's probably worth it.

To be honest, 0.43 Air Changes per Hour (ACH), or 1.22 m³/²/hr, is OK, but not a lot better than the 27 year old PassivHaus requirement of 0.6 ACH. UK building regulations are pretty poor, in terms of energy efficiency standards, and haven't really improved much in recent years, they are still decades behind the requirements of other many other European countries. Countries like Ireland have massively improved their building regulations, for example, to the point where Dublin are now looking at requiring all new houses built there to meet the PassivHaus standard, I believe. This is definitely a step in the right direction, but sadly the UK doesn't seem to want to improve new homes, and is still churning out thousands of new houses a year that are pretty woeful in terms of performance. We used a semi-rigid duct system for our MVHR, probably the easiest system to install when there isn't much room. There are several variations on the same design, as HB+ seem to have licensed it to many other manufacturers. All the duct of this type has the same dimensions, it's mainly the end fittings and plenum chambers that vary from one supplier to another (plus the cost!). The MVHR we went for is an expensive Genvex unit, as it includes an air-to-air heat pump, so can either warm or cool the fresh air feed to the rooms. For us it made sense, as our house is in a very sheltered location, cut back into a hill, and faces South, so tends to be in a warm spot, especially on still, sunny, days.

Welcome, and I have to say that finding a plot was one of the hardest parts of our build. It can be a real struggle in some parts of the country to find a viable plot at a good price.

Depending on species, there can be three types of roost, maternity roosts, which are spring through summer, hibernation roosts, which are late autumn through till spring and foraging roosts, that are temporary stopovers during the active season, often used for just a short period whilst a particular type of food is on the wing nearby. Pipistrelles (both species) tend to use stopover roosts a fair bit, as they switch from one feeding area to another. (sad, I know, but my late father in law was a bat warden, so I accidentally absorbed a fair bit about their habits..........)

A general rule is that you don't demolish anything before getting planning permission for a replacement, even if that replacement might fall under Permitted Development, as there is always the chance that the new planning application will be refused as it stands, or have a condition applied that removes Permitted Development Rights. There have been cases where people have had planning permission for a major renovation, for example, and then had a wall fall down during the process, that rendered their planning permission null and void, meaning a stop to all work whilst they submitted a new application, plus the risk that the new application may be refused. Unless you are 100% confident of the outcome, I think it's probably wise to hold back on any demolition until you have the planning permission approved, just in case.

Years ago I fitted a coffin tank, to replace an old slate cold water tank (the big sheets of slate ended up as two hearths!). I had the same problem of not being able to fit the feed at one end and the take off at the other, because there was virtually no access at the far end (it was lodged on to a massive stone chimney breast in the loft). The fix I came up with was to stick the 22mm tank fitting in the lathe and machine off the stop inside, so a 22mm pipe would go right through. I then fitted a long take off pipe inside the tank that drew water from the far end, rather than the end with the fitting. Worked a treat, for the four years or so we stayed in the house.

My concern would still be obsolescence and emergency repair, though. Heating (and ventilation) seem to me to be just a bit too critical to leave to a system that may not be that easy to fix by an ordinary heating engineer. I accept there are electricians around who have the specialist knowledge to fix this stuff (although not very many, I suspect), but heating engineers tend to be a both plumbers and electricians, having system knowledge that's often specifically applicable to plumbing and heating systems. How many heating engineers would understand enough about a Loxone control system to fix it on an emergency call out over the Christmas holiday, for example? You could end up calling out both a Loxone-knowledgable electrician and a heating engineer, so both could check their respective parts of the system to find a fault.

Websites are, in my experience, a pretty poor way of finding standard building materials. It's better (and usually cheaper) to go around (in person) to all your local BM's, give them a list of everything you want, and get the best price. Often they will price match if you try - my local independent always asked me what the best price I'd had was and tried to match it, even for stiff that was cheap on the web.

I think concern about apps controlling long-lived domestic equipment is extremely well justified. The life cycle of IT kit in general is massively shorter that stuff in houses, and we regularly see items of hardware that are just a few years old lose all support. Two examples, the gizmo my other half bought to transfer photos from her iPad to a USB stick lasted 6 months before an "update" made it into a useless paperweight, my scanner that stopped being supported two years after I bought it and so is similarly a paperweight, as there are no drivers for any newer software. As another, commercial, example, my last work programme included building offices and labs for 900 members of staff. When it was designed a "state of the art" Building Management System was installed, that included hundreds of sensors all over the building, central control of everything from climate to lighting etc. This was all controlled by a relatively small server rack and a single terminal. Within a year of the building being completed, Microsoft announced the demise of the underpinning operating system. A year later the hardware was all made obsolete by the manufacturer, as they had upgraded in line with Microsoft changing the operating system. Nothing was backwards compatible. The choices were to spend the thick end of £100k on an all-new system (that would probably be obsolete again within 5 years) or take the slightly bizarre action of scouring eBay and buying up every spare for the two year old system we could find, to give us a working buffer stock of spare for another ten years or so. We took the latter action, as there was no way that I was going to face the Public Accounts Committee and tell them that our state of the art, BREEEM Excellent rated, new flagship building was already obsolete...................

FWIW, I used planted stops, as for an amateur they are a great deal more forgiving. My only regret is pinning and glueing them in place (they are oak, like the linings) because, even though I tried very hard to fill and stain the filler in the pin holes to match the oak, I can still see where they are and it annoys me. Apart from those filled pin holes, there are no mechanical fastenings on show anywhere in our interior oak joinery - the fixings for the linings are hidden behind the planted-on stops (another good reason for using them!).