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Crofter last won the day on May 6

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About Crofter

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  1. Well it's pretty much the whole point of passive house design. There is a great deal of 'waste' heat given off by your hot water system, as well as fridges, and even the occupants of the house. So the idea is that you insulate the house to the point where it only needs this background heat input to achieve an appropriate temperature. There's also solar gain to consider. It's not MVHR as such that allows this- it's more down to the level of insulation, and not having oodles of windows (even the best windows lose heat at three times the rate of a standard wall).
  2. I used JJI joists and yes they are a bit more expensive than a solid timber joist. From memory I would have spent around £25 on each joist in solid timber, and £36 for JJI. So the total extra cost over my build was around £165 (it's a small house, only 15 joists were needed!). The advantages are several. Much much easier to work with- I installed them all singlehanded as they were so light. Every single one was perfectly straight. Thermal bridging greatly reduced. They use less timber overall so are probably a more ecologically sound option. I don't have any experience of posi-joists, but I imagine they offer similar advantages.
  3. Crofter

    Membrane over membrane?

    I put a lot of research into my membrane choice- everything is there on the BBA certs fr tear strength etc. Ended up using Cromar Pro Vent 3 on the roof, it seemed good value for money given the specs, and it lasted very well exposed for many months on a fairly exposed site.
  4. Crofter

    Membrane over membrane?

    I had my membranes exposed for longer than most people (not quite as long yours though) and whilst the roof remained perfectly watertight and undamaged, the wall membrane at the SW corner suffered some rips and tears. After advice on here I put a patch of new membrane over the top, as there didn't seem to be any downsides to having multiple layers.
  5. Crofter

    Door Linings/Frames - Questions

    I had the same headache, ended up buying dressed all round timber and cutting out my own joints with a circ saw and chisel. Worth hand picking your timber at the BM to avoid anything badly twisted. When sizing the liner, the rule of thumb I was told was that you should be able to fit a 2p coin all the way around the sides and top. One essential thing to have to hand is a pack of plastic spacers in 1mm increments- these let you pack out the liner precisely. I didn't cut the doors down at all and propped them up in the doorway, building the liner around them. This ensured that everything was square. I screwed the linings and then filled the holes left by the heads. Primed and painted all skirts, arcs, liners and stops. The walls are all white so the pale blue painted skirts/arcs are a nice feature that gives necessary character. It's also so much easier and cheaper this way.
  6. 12m is a pretty big span. Playing around with the interactive span calculator on the JJI website ( shows that you can only go up to 8m span, and that requires 450 deep joists at only 300 centres. Unless you have a completely open first floor it will almost certainly be worth having a supporting wall.
  7. With windows, I found the savings are to be made by keeping things simple. So go for big panes, not lots of little ones, and have them fixed where possible. Incidentally the bigger panes lose proportionately less heat than a bunch of smaller panes in the same frame. Other tips- source your own fittings where possible. I was shocked at what sparkies and plumbers are charging for fittings, despite them supposedly getting a good deal on their trade accounts. It might be worth checking with them beforehand that they are happy with the quality, just in case. You can also get good deals by being ruthless about pursuing low prices. There seems to be two different worlds out there- you get the people selling to the Grand Designs, Homebuilding and Renovating crowd, and then you get people selling on eBay/Amazon etc. I went online for my bathroom and the whole thing came in well under £1000. A posh high street design studio wanted to charge me double that just for the walk in shower enclosure alone.
  8. I don't have the full breakdown as it's on my old laptop, but rough figures from memory are: - Fees £1200 (planning, building warrant, road crossing, road opening) - Access £5000 (plant hire and several lorry loads of stone) - Drainage £6500 (Puraflo system, septic tank, soakaway) - Services £3000 (water and e;ectricity- no phone line) - Foundations £700 - Structural timber work £4000 (cost to build the shell inc sheathing on walls and roof) - Roofing £1200 (corrugated iron) - Cladding £1000 (larch) - Windows £4500 (3G aluclad) - Bathroom £800 - Kitchen £2000 That lot adds up to about £30k- there was another £10k on the stuff I can't remember off hand, such as plumbing, wiring, plasterboard, joinery, flooring. I've not included the furniture or furnishings. If the site had been easier to develop, with services already in place, then the project would have cost under £600/m2
  9. My build came to about £1000/m2 with three years of DIY labour. So if I costed in my time at say £20k a year, my build actually cost £2300/m2. I would say getting a house built for you by someone else at under £1000/m2 is pretty good going. It's hard to build small houses down to a same price per m2 as a bigger house. Lots of fixed costs, or at least costs that become disproportionately large when the house is small. Fees, services, access, appliances, barely scale at all.
  10. What does this requirement entail? I am aware of a couple of BS numbers for caravans and mobile homes but I concluded that these only applied to use in a caravan park or as a touring van.
  11. Sorry I'm a bit late to the party here! There tends to be some confusion about the status and benefits of portable buildings in terms of regulations, planning etc. The planners want to know what a building looks like and what it will be used for. They don't care how you actually build it. Building control determine how you actually build, and if you satisfy their requirements you end up with a completion certificate, which then allows you get your VAT refund and lets you get a mortgage. To be exempt from building regs there are two routes that I am aware of: - stay below 30m2 and do not include enough facilities to make the building actually habitable (so think garden room, studio, man cave, etc) - build within the definition of a portable building, which is derived from the Caravan Act 19xx I'm only familiar with Highland Council's definition, which is very simple- 10ft ceiling height, and footprint less than 6x18m, with the building being monolithic or capable of being split into two sections. From my own correspodence with the local BCO, I was told that the building did not need to be capable of being moved off the site (mine would not fit down the single track road)- but if it could be moved around within the site, that is OK. Basically this means that you need to stick to the dimensions given, and make the structure from one or two boxes that can be towed, craned, etc. I ended up building on piers with a suspended floor- a more conventional build on a raft or with multiple sleeper walls would not, IMO, meet the definition as you could not really get underneath it and support it when moving it. A solid floor build would clearly fail because you would leave the floor behind! I'm not sure how Rich's supplier is able to zero rate the build, obviously good news for him if that's the case. I tried to get my own zero rated but it seemed that that would be impossible without a completion certificate, and anyway as it would not be my principle residence I was not eligible anyway. If you are building it as a letting business, you cannot claim back the VAT- unless your letting business is going to be VAT rated itself and charge VAT on all of the letting income, which would clearly be a bad move in the long term. From an engineering POV, I don't actually think a log cabin lends itself at all well to being a portable building. You would be far better off with SIPs.
  12. Crofter

    I-Beam vs Standard timber

    I can't answer your specific questions about using I-beams for walls, but I did look in detail into using them for joists, vs solid timber. For my 16ft span, solid timber would have worked out about £20 per joist, whereas my JJI engineered I-beams of the same dimensions were £36 each. So you are paying nearly double, for a considerably reduced quantity of timber! But the benefits are enormous. - much easier to handle due to reduced weight - totally dimensionally stable, giving perfect flat and squeak-free floors - easy running of services through the web - far better thermal properties because thermal bridging is almost eliminated To me, it was a no brainer to go with the I-joists. In the grand scheme of my build, it added less than £300. For walls, I believe that a Larsen truss may be a more common way of achieving what you are looking at.
  13. Crofter

    Dripping tap... IKEA

    eBay! e.g. (no connection/endorsement etc- simply the first one on the listing). If you get one with too long a spindle, it will still work, but you will see some of the brass part showing. How do I know this... It's a straightforward job needing a couple of spanners, but you will need to isolate both sides of the tap.
  14. Crofter

    Dripping tap... IKEA

    It's not just needing a new ceramic cartridge, is it?
  15. Crofter

    Buying a used van or pick up.

    The caravan was from the mid 80s so predates the need for plating. The axle itself had a plate saying 800kg. No idea what the finished trailer weighed, obviously much less than the caravan did. I've never been pulled over for a weight test, police are probably spread a bit thin round here. You hear of people trying silly things with converted caravans, like using them as car trailers, which gives them a bad name. But for picking up long or bulky loads it's ideal. I only had a hatchback to tow it with anyway so 800kg was about as much trailer as I could use.