Crofter

My build is working out at just under £1000/m2 if I include everything except land costs and final decorating/furnishing. If I take out the drainage system, services, and access, the actual building itself is about £500/m2. But, and it is a big but, this is because I have literally done everything myself except for driving the digger. So what you are seeing is materials costs only (plus plant hire). The spec is reasonably high (3G alu clad windows, high levels of insulation, decent woodburner). It will have taken a year of my life full time, and a year or more part time prior to that. All for a 43m2 bungalow! The small size is what makes it feasible to go completely DIY, but it also pushes the price per m2 up a hell of a lot. If I build another one, it will be bigger, and I will get a labourer...

What are the joist spacings, board thickness, board width? I'd just be a bit worried that without being locked together tongue & groove, they might deflect and move too much.

Thanks. The releveant part appears to be:

I have no experience of this sort of project at all but it sounds interesting. So you would take up all the existing floorboards and work from above- how would you keep the PIR in place? Little 20mm battens running along the bottom edge of each joist perhaps? You will possibly lose some strength/rigidity when you space out the (T&G?) boards. Will be interesting to see what other people say.

I like it in principle- who doesn't like to play with fire- but just not sold on the end look. A less scorched effect looks brilliant, IMHO (e.g. http://www.urbanrealm.com/buildings/1144/Blakeburn.html) but presumably still needs some sort of treatment as the charring is not heavy enough to do the job.

If one were to build a leaky house on purpose, where would be the best place to put the leaks? This is not an entirely facetious remark: my neighbour was complaining that his house has been built 'too airtight' and he is counting on the sparky and plumber making a few holes. I find it hard to believe that these randomly placed holes are going to result in a better environment than a planned, active, ventilation system.

Ah and I presume you would need PP for the oil tank?

Is A2A a ducted warm air system, then? Tempting price, for sure, but for a house that already has rads and pipework installed, it would be a much more disruptive installation tuning the ducts around the place. Another question comes to mind- would a building warrant be needed to install a new heating system? I have come across reference to regulations about the storage of oil so wondering if this is enforced via a BW?

How does the circulation of air via MVHR compare to the effects of convection? Of course in a PH you don't have the heating on (or it is a very low background heat through UFH) so there will be less convection happening than an ordinary house.

Thanks, to be honest I'm not sold on the black look. Not really part of the vernacular around here, although the planners are fairly open minded IMHO. I want to avoid using any sort of traditional paint as it would be much higher maintenance than an oil or stain and the wood is not smooth enough. Leading contender at the moment is probably the Barrettine stuff. I'm concerned that the rough sawn planks will drink up whatever I put on them, so I need to go for something fairly cheap and cheerful. For initial application, I am going to lay out all of the planks inside the wind and watertight shell of the building so I will not be held hostage by the weather (it has been known to rain occasionally on Skye).

Hmm, maybe we should ask @Barney12 ... I would have to run it past the planners, as I said I would be going for a natural finish.

Whoosh....

My council's website mentioned a list of BC approved contractors who would carry out perc tests, but when I phoned to ask for this list they sounded very confused and then said they no longer had such a thing, and 'normally your builder does it for you'. So I just did it myself, it's really rather easy, just a bit tedious. My drainage system is now complete and signed off so there do not appear to be any problems. It could well vary between different LA areas though.

I don't have the figures to hand, but I believe that the UK is way behind many other countries when it comes to the proportion of houses that are self built.

Good idea from Dave there. My preference would be to pursue the first solution as I would imagine it could be easier to get permission to lay pipes containing treated effluent, rather then raw sewage, especially across someone else's land. If drainage was refused based on site conditions, there are specific ways around things like high water tables, although proximity of boreholes or water courses is harder to do anything about.

Extra ventilation can definitely reduce this. I had a big condensation problem in my loft (retro fit insulation, no ventilation) and simply cracking open the skylight has made an enormous difference. I will eventually add some high level vents as well when I have some time.

So, my larch is now onsite and I can no longer put off the decision on treatment. By my estimation, I have 120m2 to treat- this is the front face only of the back layer of boards, and the front plus sides of the boards that will go on the top layer. I'm getting pretty bewildered by all of the options available. Sioo works out at about £850 which is just too much- about the same as the wood cost itself. It would have to have magical properties for me to justify spending that much. Plus, as has been said, it is an accelerated weathering system and what I really want is to preserve the fresh cut look. Next in line are Osmo products- either two coats of the UV Oil, or a base coat plus the UV oil on top. Either way works out at about £450. I am inclined to go for the two different products as they have quite different jobs to do and it works out about the same cost. Then we enter the world of cheaper finishes with more recognisable names, e.g. Ronseal, Barrettine. There are a wide range of products available including ones for log cabins, which sounds fine, but what I need to do is avoid cheap and nasty stuff that might only be suitable for a garden shed. These products would work out around £300-£350. Comparing the different products is tedious as the coverage and number of coats varies, so you have to be methodical and work out the total cost for each option. I'm starting to see the appeal of leaving it untreated!!

Solar gain is a potential issue, but I have heard good things about IR-blocking films that can be applied to windows to make a big difference to how much heat is absorbed. As far as I understand, all you have to do to turn a passive house into an active house is to open some windows. But it's much harder to do it the other way around.

No current EPC- house hasn't changed hands in over ten years. Would one be necessary before being able to let out? I did live in a place with an electric boiler for a short while- it was also ex council. I can see the benefits for the landlord but I don't remember finding it particularly cheap to live in myself. Is it possible to fit some sort of low level cut off for an oil tank, so that it shuts off below a certain level but does not subsequently need to be bled?

Thanks Nick, good info. I'm likewise a fan of cooking on gas. We had a big dual fuel range cooker in our last house and even running a wok burner etc the 47kg propane cylinder would last about 18 months (admittedly only a 2 person household). Inicidentally, we found that we could get gas at less than two thirds the cost of Calor, and with no bottle deposit, simply by shopping around- although in the scheme of things it's a very small annual cost. However for the house in question a new electric cooker was recently fitted so I guess that will be staying. Is there anything wrong with a cheaper oil boiler? E.g. Screwfix do ones from around £850. I don't think there is anything wrong with the existing DHW tank so what would be the benefit of a combi in this instance? Ta

1960s at a guess. Cavities are filled and there is some loft insulation, not sure how much. Suspended timber floors, not insulated. Timber double glazing about 15 years old. Yes I know you seem to have had some bad experiences with tenants. My thinking is that it is probably worth upgrading the house a bit to move it up the price range and avoid being the cheapest rental on the market. Storage heaters would involve a fair bit of work though, removing the existing radiators and running new wiring around the brick and plaster walls. Also I don't think the owner would want to be locked into a system with high running costs as he is currently living in the house and may wish to do so again at times in the future.

The DHW could stay as-is I suppose, but install an E7 meter. What sort of ballpark figure would an ATAHP be? The prices don't seem to be readily available online unlike e.g. oil boilers. It's a 2 bedroom house by the way so not enormous. I don't know the exact size but it must be in the region of 80m2.

Asking for a friend... Ex council house currently served by an open fire with back boiler feeding radiators. DHW off this system with additional electric immersino heater. The owner wants to rent the house out and is thinking that it would be beneficial to update this system but obviously does not want to embark upon a major project at high cost. I am advising him to research ASHP or, if he is feeling brave about future energy prices, just go for oil. No mains gas, unfortunately. He is interested in a multifuel stove but my feeling is that prospective tenants would not want the hassle, and most people these days don't expect to wake up to a cold house, which you would get unless you incorporated a TS.

Not exactly what you are describing, but I got my insulation from 'seconds and co' who claim to be the only seller of kingspan seconds. Basically if a batch has too many flaws, Kingpan have to landfill the whole lot and these people take it off their hands for free, then bundle it up into pallets and sell it on at about a third of the normal cost. i got eighty boards this way. Two of them are closer to 40mm rather than the 50mm I require; about half a dozen more are a bit skinny but close enough that I will just use them anyway. Two have big voids within the foam, one was right at the edge and the other in the middle- you can tap the skin and play it like a drum. I will fix these using expanding foam. Many of the others have creases or slight hollows running in lines down the length of the board, where the foam filling has not fully risen (I guess they inject it from a row of nozzles about six inches apart?). Perfectly usable. And then there are the lengths of the boards, almost all are a little under 2.4m; sizes vary a lot but the majority are about 2.27m.

It wasn't actually the SS ones that I got, but 'TurboSilver' whatever that means. Won't be directly exposed to the elements, but will be behind the cladding.