Jeremy Harris

In the case of a self-builder, then the data isn't coming from a third party, though. I designed and specified our house, and did the building regs submission, so I was the one that would have supplied the base data to the assessor, had I opted to go down that route. In my case, I opted to just send the assessor the FSAP file, together with the air test certificate (which was the only bit of independent evidence, other than my word), as he happened to use the Stroma software. I can't see how value was added for us, that's all; I'm not being critical of the role of assessors.

Not sure what Nick means, but the only seasonal buffers I've heard of have been a bit mixed in terms of their installed performance. I'm aware of one in Ireland that was sold as being able to store excess summer heat to keep the house warm in winter, but my understanding is that it didn't really work that well. I have some photos of it somewhere, and it looked to be a bit of an expensive experiment, one that I think the client paid for.............. There's another that was in Passive House magazine a couple of years ago that was reportedly better. That was a massive cylindrical water tank that formed the core of a large curved staircase. I can't remember the volume, but it was many thousands of litres I think, and well-insulated. I have doubts as to whether the concept of a seasonal buffer makes sense, economically, as the engineering costs seem very high for what is only a modest energy cost saving.

One reason I like the Prius. You can easily fit 3m lengths of pipe, etc in it. It has the most useful load space of any car I've owned, better than the Pajero in terms of usable load space. It easily takes a washing machine in the back, too, with room to spare.

I'm not at all sure. Blown cellulose insulation is treated with borax, I believe. As far as I can tell from a quick search, it looks like straw bales are inherently fire resistant when incorporated into a structure: http://www.sustainablebuild.co.uk/constructionstrawbale.html http://strawworks.co.uk/faqs/

Straw bales have a lot of advantages, and if encapsulated inside the structure aren't a significant fire hazard. The secret is to stop air getting at them, which you have to do in a house, anyway, to both make the house air tight and provide a vapour control layer on the inner surface. The advantages of bales is that they can provide a reasonable level of insulation, they are reasonably priced, they have a fairly high decrement delay (which helps to stabilise internal temperature) and they are pretty quick to build with. The only real down side with straw bales, particularly for a small house is that they are big, and need to be to give a decent insulation level, so the walls end up being around half a metre or more thick. This reduces the amount of usable space inside the house, to a greater extent than for a larger house. Having said that, the 300mm of cellulose we have in our timber frame walls also ends up making the walls pretty thick; I think our walls are around 430mm thick overall (we don't have any masonry on the outside).

I think the "£41k to make" is the give away with the Welsh houses. Our basic house only cost around £53k to "make", the bulk of the cost is in all the other stuff. Site costs can be high, especially for self-build plots, as often these plots are only available to self-builders because they have site costs that are too high for a builder to be able to make a profit on. Often the plot cost is reduced because of this, but as the supply of plots is a lot lower than the demand, there is still a "self-build premium". Our plot is, perhaps, at the extreme end of this phenomenon. It's a small plot, just 35m x 16m. It would have an open market value here in the Mid-South West of around £150k. We paid a lot less than that for it, because it needed around £56k of ground works, just to get a level bit of land to build the house on. On top of that was another £12k to get a water supply (initial quote was nearly £24k), just under £4k to get the electricity sorted and around £4k to put in a sewage treatment plant, as that was cheaper than the ~£18k to connect to the main sewer. So, before we'd even started the foundations we had incurred site preparation and services costs of around £76k. Land prices around here are a bit lower than in the South East, so much so that when we were plot hunting we drew a line on a map from around Oxford, South as far as the coast at Southampton, and only looked in areas to the West of this line. We pretty quickly realised that we couldn't really afford to buy a plot East of this line, so just excluded that area completely, even though we were living practically on that line at the time. We had around £150k to £180k available to buy a plot, and were only looking for enough space for a 2 bedroom house with a small garden.

@Crofter's blog is here: There are a fair few myths about what you can and cannot build on Green Belt, and the starting point is that there is a presumption against building, erecting, or parking any form of dwelling. Getting permission to put something on Green Belt would be pretty time consuming and costly, so is not really an option if you want to keep costs down, I think. Have you actually got a building plot? If not, then that's going to be the first hurdle, as it can take a long time to find a plot at an affordable price, especially in some parts of the country. In high housing demand areas, the majority of the possible plots have already been developed, and despite slight loosening of the planning restrictions, it's still near-impossible for a self-builder to gain planning permission on land that's outside the development boundary. The big developers can do it, as they make substantial payments to local authorities, which, in effect, means there is a net benefit in terms of revenue that the local authority can use for infrastructure, education, etc. There are some self-build cooperatives around, where groups of people have got together to build a small development, at an affordable cost. There are significant advantages in this, as it allows the sort of housing density that local authorities like to see for affordable housing (something that can be hard to meet for a single self-build) and the costs are reduced because of the economy of scale (it's generally a lot cheaper, per house, to build ten houses on a site than one house on a site). If you can't find a local cooperative, then you could, perhaps, look at starting one.

I wish you the greatest luck, but think you've got a great deal of work ahead to get down to £500/m². If you're in SE England then your task will be a great deal harder, just because labour and other costs will be higher than somewhere like Wales. I think the cheapest build here may well be @Declan52's build, where he did a great deal of the work himself. He's also in a pretty cheap area, compared to SE England, so would guess his costs may well have been around 20% to 30% lower because of this. I'm not sure what his build came in at, but have a feeling it was around £800/m² or so, which is extremely low, probably the lowest I know of. Your going to need foundations, with low thermal bridging if you want a low energy home, and just the cost of the cheapest type of insulated floor and foundation is going to eat up around 25% of your budget, even with you doing all the labour, and getting materials at a keen price. Designing a thermal-bridge free, internal steel portal frame structure is certainly possible, but you'll need to do a lot of the design and thermal modelling work yourself to keep costs down. The devil will be in the detail, like how you deal with the wall to floor junction, how the insulation is continued from under the floor to the walls and how the insulation and rain screen is fixed to the structural frame. It's quite a neat way to build, but I'm not sure that it's particularly cost effective. I have a feeling that a well-insulated timber frame may well be a fair bit cheaper, overall.

There's little technology in the blower. All the aeration treatment units I've looked at use fish pond air blowers, usually Japanese made and originally designed for use with Koi ponds. The process is pretty simple. The treatment plants have a settling area, plus an active aeration area, with a perforated air pipe that blows low pressure air out as a stream of fine bubbles at the bottom of the tank. These bubbles to two things, they increase the oxygen content of the contents, which encourages aerobic bacteria to breed and feed on the effluent, and the bubbles lift material from the base of the unit and cause internal circulation, which reduces the amount of undigested solid matter. Some treatment plants are better at lifting solids and circulating them than others, I believe. In general, I suspect that the conical tanks are probably more effective at lifting and digesting sludge than the flat bottom tanks. The main impact of this is that the conical tanks may well have an increased de-sludging interval (the manufacturer of ours suggests every two to three years, for example). There seems to be a fair bit of copying of ideas going on with these things, with some models being very similar to those from other manufacturers. As an example, our BioPure looks very similar to the Condor unit that ProDave has fitted. I believe the cost was around the same as well, IIRC we paid around £2k for our unit, with pump and alarm system and a pumped outlet option (which increased the cost by a couple of hundred pounds). I think it's well worth shopping around before making a decision.

Welcome. Building for £500/m² is a very, very tall order, and frankly I doubt that it's possible, even with a great deal of work done by yourself, with almost no contractors involved. The cheapest self-builds are probably around £800 to £1000/m² and can only be built at that price because of a lot of hard work by the self-builders. I'd guess that a lot of self-builds tend to come in at between £1200 to £1500/m², at least those that don't have a particularly high specification. Up the specification and it gets easy to exceed £2000/m². Also, a lot of the cost depends on where you live and what the local labour rate is, and also whether some materials are cheaper or more expensive locally. For example, steel fabrication costs have a fair proportion of transport cost in the total, as well as having plant hire costs for erection, and in some areas that can increase the cost a lot. To give an idea of cost, our build is 130m², and I did the design (no architect), the planning and buildings regs submissions, project managed the ground works, did all the plumbing, heating and ventilation system installation myself, did almost all the internal joinery myself, fitted the kitchen, bathrooms, WC etc myself and a fair bit of the electrical work as the qualified electricians "assistant". The cost came in at around £1380/m², or around £180k. I could have reduced this a fair bit by having lower spec joinery and cheaper kitchen and bathroom stuff, and may well have been able to manage to get the cost down to about £1250/m². That's still a long, long way from your £500/m², though. Even our basic watertight shell and foundation came in at around £410/m², without the roofing, windows, doors etc, just a membrane clad shell. It did go up in four and half days, though.

I used small 12V switched mode power supplies, the type that have a built in fuse and that are in metal enclosures, and fitted them in the ceiling void. The metal cased units don't seem to present the interference problems that some of the plastic cased units do, but there are some decent plastic cased units around, as others here have found them (I can't find the thread at the moment). Bell wire is a no-no, as generally the current requirement may well exceed its rating and the voltage drop will be too high, even at a pretty low current. There's nothing wrong with using ordinary T&E for SELV lighting, but best to mark the ends of the cables to indicate that they are being run at 12V. 1mm² T&E is good for 13A when run in a ceiling void with 100mm of insulation, 1.5mm² T&E is good for 16A in the same conditions, but the important thing with SELV is the voltage drop; it's far more critical than with LV. You want no more than 5% voltage drop, which is 0.6V. 10m of 1mm² running at 10A would have a voltage drop of around 4.4V, which is way too much, the highest current you could run through 10m of 1mm² T&E and stay below 5% drop at 12V would be about 1.4A, and for 10m of 1.5mm² T&E the highest current would be about 1.7A. If you use shorter lengths of cable, then the allowable current increases in direct proportion (so a 5m length doubles the above maximum current for an allowable voltage drop). I fitted the power supplies pretty much centrally for each group, then ran radials out to most of the LEDs, to keep the voltage drop down. Some radials have a couple of LEDs on, just because it made the wiring a bit easier. All our ceiling LEDs are wired with 1mm² T&E like this, with a maximum cable run of around 2m or so. Using T&E also means that the cable is mechanically tougher and easier to install. To make it easier for anyone to work out what these cables are in future, every one has a white heatshrink label on the end, identifying the circuit and the voltage. I also used red and black sleeves over the brown and blue cores, to make it clear which is the positive and which is the negative.

It's highly likely that heat loss, and hence heating requirement, will be dominated by the ventilation heat loss, rather than the fabric heat loss, so to get an idea of how the two impact on the total heating requirement you really need to do some sort of heat loss modelling. It doesn't need to be very complex in order to size a heating system, and I would suggest not using SAP for this, as that's not what it's designed for at all; you need to know what your worst case heating requirement is likely to be for the coldest weather you are likely to get, so knowing how heat loss changes with outside air temperature and chosen room temperature is key. I wrote a fairly simple spreadsheet in order to be able to see what effect trading off different elements of the build would have on the heat loss. It's a bit crude and no where near as comprehensive a PHPP or SAP, but others have found it pretty accurate, and it came within about 10% of the full PHPP model for our house, which seems pretty reasonable for such a simple model. It's here if you want to play around with it: http://www.mayfly.eu/wp-content/uploads/2017/01/Fabric-and-ventilation-heat-loss-calculator-Master.xls As @PeterW has mentioned, it's quite probable that hot water will need more energy than heating, and it can be challenging to get a combined heating and hot water system to work well. It may well be better to split the two requirements into separate systems, so each can be sized differently. If you have mains gas, then using that, at least for hot water, makes a great deal of sense, as it's both cheap and relatively low CO2 (which, incidentally, makes getting a decent SAP EPC easier).

Welcome. I've never heard of this company, but the aeration treatment system is a common one, and some of the stuff in their video is a bit misleading, as there are many other plants that fit the air pump in a chamber inside the unit (our BioPure does, for example), and few that run compressed air lines across the ground as they illustrate, or that have the pump in an indoor wall mounted enclosure, like the one they show (I've never seen one like that). They've given timed/pulsed aeration a new name, but again other plants do the same, in order to reduce pump power, and pretty much any pumped system can have a timer added to turn the air on and off in a cycle, in order to reduce power consumption. Most units with continuous run pumps over-aerate, to be on the safe side and met their maximum person rating, so the aeration can be safely reduced and still give good treatment. I'd suggest having a look around at some of the other units around, and comparing the price and performance, some mentioned ihere, perhaps: There are also some other posts here on treatment plants, comparing their relative merits, prices, etc, and a search will probably bring up some additional info. I'd also add that having the air pump in a chamber in the tank is a bit of a nuisance, I've moved ours out of that chamber and into a stone chamber alongside the drive, as you need to get at the pump, to replace/clean the air filter at least annually and replace the diaphragms every couple of years, and lifting the lid on the treatment plant and leaning in to the equipment chamber is neither easy nor pleasant. There's also a very slight hum when the air pump is on, even with the pump in a chamber in the tank, we found. Not enough to be a nuisance, but just about audible on a quiet night, when standing near the unit. Putting the air pump inside a stone chamber has reduced the noise, as it's lost the slight resonance from being in a fibreglass box inside the hollow space at the top of the unit's main chamber. You also really need an alarm, for pump failure, which means adding something that can be seen and heard when there's a problem, and that's better placed away from the unit, where it's easier to see and hear. Our unit was supplied with a battery-backed alarm that sits inside the equipment chamber, and flashes a red light on top of the unit, and make a gentle beep, if air pressure is lost (which is usually either a pump diaphragm failure or a power loss to the pump).

When I was around 12/13, my (disabled, wheelchair user) father decided that I should build a curved raised bed, around 40ft long x 3ft high, so he could plant roses that he could get at. At the time, we were having a two storey extension built, to provide a flat for my grandmother and a downstairs bedroom, etc, for my parents. The builder was a great chap, who showed me how to mix mortar, lay bricks and point them (I still have the bit of bent galvanised bucket handle he gave me to do this). I dug trenches, poured concrete footings and then started building the walls. All the time I was laying the bricks, my father was sat in his chair on the lawn, listening to the cricket and keeping watch on my brick laying. During a lull in the cricket he'd gently remind me that Churchill (who's middle name I share*, because my father was a great fan of him) could lay 300 bricks a day. I think I struggled to do 100 a day, and he was not best pleased....................... *apparently he also wanted to name me Winston, but my (Irish) grandmother told him that it was bad enough him giving me an English name. She didn't much like the English, especially as she got older.

Sadly I'm absolutely sure you're right. I may be just a bit cynical, but I can't help but think that some of these government schemes are partially dreamt up as a way of creating new jobs. The government decides that, instead of enforcing building regulations to reduce energy consumption, by tightening the existing inspection regime (which is clearly a bit lax - there is a fair bit of evidence that shows this) they will invent a new requirement, laid over the top of Part L1a, that needs more accredited people to run it (this is not in any way an attack on energy assessors - they are just taking on a government-mandated role). We've seen exactly the same approach taken in other areas, too, like the Microgeneration Certification Scheme, that typically seems to add at least 20% to 30% to the cost of any applicable installation, often more. In our case, a certified installation of our monoblock heat pump would have doubled the installed cost, an increase we could never have come close to recovering from the Renewable Heat Incentive payments that a certified installation would have allowed. Are MCS accredited installers something special? No, they have no better qualifications than those that any domestic heating company employees would need.

Given they've got CCTV, I wonder if anyone will upload it to YouTube?

Any sampled audit check is, as far as I know, purely a visual inspection. There are two stages, first a design SAP, which is based on how the house is intended to be built, and which is only held on file by building control, then an as-built SAP, which is supposed to be an accurate representation of how the house was actually built, with things like the measured air permeability, rather than the design target air permeability added, plus any other changes made as the house was built incorporated (in our case, I'd changed the model of MVHR and the heat pump from those originally specified). I'm pretty sure that any audit wouldn't go so far as to include a thermal imaging survey. I went around a new development last winter with a thermal imaging camera and it showed lots of missing wall insulation, a lack of insulation (or bad air leaks) in several dormer windows and what looked like air leaks around windows and doors. Every house was much the same, and I looked at around 30 houses all told; the major defects (like the heat loss through the dormers) was common to every house on the development. I'd watched these houses being built (I drive past the site every day, and there's always a traffic queue there, so I get a good look), and I'd already spotted missing insulation and insulation fitted with large gaps, which was the only reason I went around with the camera when they were completed.

Maybe, but then, realistically, how could any assessor add any value as far as I was concerned? After all, I'd done the design SAP, updated that to reflect minor changes during the build to produce the as-built SAP, and so all the work was already done. What's the difference between me emailing an assessor all the base data, and emailing an assessor an FSAP file with that same base data already entered?

I'd second just going for SELV, makes life a lot easier (and cheaper!). I'd run a decent, immersion-rated, two core cable (something like H07RN-F, or perhaps H05RN-F/3182P "pond cable") inside a length of buried conduit. You can then make off the tee junctions easily with pond cable junctions, like these: http://www.ebay.co.uk/itm/Waterproof-Power-Cable-Connector-Joint-Submersible-Water-Pond-3-Core-CE-IP68-/182124643664?var=&hash=item2a67798550:m:mgk4Egab0ithpw7FDF8uGTA which should fit the above cable OK.

Very true. Part of the problem is that there are just so many people holding their hands out for cash from self-builders. On a per-house basis, self builders pay massively more for assessments, consultants etc, purely to tick some box in some overly bureaucratic process that is of no net benefit to them at all. Taking our build as an example, we were asked to cough up for the following: 1. A flood risk assessment that was barking mad, as the house is on a steep slope (but within a flood risk post code), with an estimated cost of between £2000 and £6000. I got around this by discovering that you don't need to show any form of accreditation to do this and can get the source data from the Environment Agency, so I did my own, which was accepted, and saved a great deal of money (I reckon that I "earned" around £200/hour for doing this!). 2. We were advised to use a Planning Consultant when we first approached the planners, as the plot had a pretty chequered planning history, with several refusals. I just sat down and read loads of local planning applications, got a feel for the way the system worked, and saved a fair bit of money by submitting the application myself (no objections, PP granted pretty quickly, without going to committee). 3. We were initially asked to provide an Ecological Assessment, as the plot is within an AONB. This would have cost another few hundred pounds, and again was pretty pointless, as the plot was covered in spoil from two developments further up the hill. Again, I managed to get around this by writing my own assessment and getting the planners to remove the requirement. 4. At the design stage I was first asked to get an energy assessor to provide a design SAP. Given that I'd designed the house, modelled it on my own heat loss model and PHPP, this seemed to be another cost that wasn't going to add value. I spent a few hours getting to grips with the way SAP worked, first using a big spreadsheet, then using FSAP. When I spoke to building control they were more than happy to accept my own design SAP, so that was another chunk of money saved. 5. For completion, I needed to get an as-built SAP, which was dead easy, as it was just a matter of updating the design SAP with some minor changes (change of MVHR model, actual air test result and change of heat pump model). All told the as-built SAP took me at most 10 minutes to complete. However, I wasn't allowed to lodge it, as that can only be done by an approved assessor, so I had to fork out £100 + VAT for an assessor to just add his name and number and lodge the EPC. I know he didn't take long on it, as I emailed him the FSAP file and he emailed me back the completed and lodged paperwork within two hours. He hadn't changed a single item on the SAP data itself, so this was just a complete waste of money for me.

Resin-filled for me, too, as any underground joint really needs to be better than IP68 (or have a specified set of IP68 test conditions); IP68 normally only has limited water resistance when immersed, and some water ingress is permissible, and that's not adequate for a buried junction that could be more or less permanently in water or wet ground. IP65 is wholly unsafe for underground use, as it's only resistant to water jets, not any sort of immersion.

It might be an idea to just get the mods to append this to the original thread.

Yes, I did install an old version of Thunderbird, imported all my old .pst files, backed up the Thunderbird imported files, then installed the current version of Thunderbird as a portable app on a USB stick. It took a bit of time to sort things out, but now I have all the archived emails organised Thunderbird seems to work well.

Seriously. It was a woman, who climbed over the security fence and over piles of building material to peer through the windows. She wasn't wearing any PPE, and in my view wasn't sensibly dressed to even enter an open building site, let alone break in after hours. She was caught on the site security camera, but I didn't actually look at the recording until after I received the phone call from the council saying that I was going to be charged council tax. The problem went away when I pointed out that there was no water or sewage systems connected and that the house was therefore not a rateable hereditament under the Rating Act. I also made a formal complaint to the council regarding their breach of site safety, and entering the site without authorisation. They half agreed about the safety thing, but pointed out that they had an implied right of access under common law, in order to carry out their statutory obligations. At that point I withdrew their implied right of access by formal notice, and informed them that I would let them know when the property was a rateable hereditament. I then deliberately withheld getting a potable water supply connected until just before completion, so stopped them getting around a years worth of council tax out of me, purely because their attitude pissed me off. FWIW, our council actually employs people to drive around, looking for part-completed new builds, so that they can levy council tax on them.

If the private road provides access to a property, then the council have an "implied right of access" under common law. This is the law that allows the postman, utilities, delivery drivers etc to access your land without committing trespass. Council officers have the same rights of access, unless the owner(s) of the property specifically deny them those rights. As an example, after my debacle with our site being broken into by a council employee, trying to gather evidence that the house was complete enough for council tax to be levied, I issued a notice to the council, backed up with signs around the site, removing the implied right of access for all staff employed by, or contracted by, the council.