I am planning to build a 3 bedroom one and a half storey house in the north of Scotland. I plan to use a 200mm SIPs structure with additional insulation on the inside of the panels. The SIPs company claim that the insulation values of the completed house will exceed passive house standards.

My main heating sources will be: solar gain, solar thermal panels for domestic hot water, and a 4/5 kilowatt wood burner with back boiler. The SIPs company are convinced that the house will not require any further heating. I’m not sure that I’m ready to take that `leap of faith. On the other hand, I don’t want to waste money on an expensive renewable heating system if I don’t need it. I would be grateful to hear from anyone who is also considering this approach or has actual experience of building and living in a passive-type house.

  • Anonymous

    I think this is great idea , and should work as they say !!!!! but you could also install pv and solar to get some money back — )))) approx 9% on investment should cost about £6000 to £9000 not bad better then money in th bank if you need any help call me as well

    Good luck

  • Tim Pullen

    A 200mm SIP with extra internal insulation will be achieving a U-value of around 0.10W/m2K which, assuming similar or better levels are achieved for the remainder of the house, will be very close to PassivHaus. And, notionally at least, you will not need any further space heating. But there are a few issues to consider.
    The solar thermal scheme is unlikely to deliver enough hot water in winter and will need topping up. In addition, it is very likely that the space heating will also need topping up in the coldest part of winter. You may have the back-boiler in mind for that but at 4-5kW output it is only big enough to do hot water or top up the space heating, not both. Bear in mind that a log-burner only achieves its rated output when it is full of logs and burning well

  • Anonymous

    We have built an 170m2 house with no central heating in northern Scotland recently. Tonight we are sitting in our open plan space with no heating at 21 degrees and the upstairs is sitting at around 20 (though quite a warm day today). It is 200mm sips like your planned project but with an MHRV system. We have a 5kw woodburner with a back boiler for extra water heating, solar thermals and a back up immersion heater on the tank. The house will require some extra space heating in winter for which we will use electric oil filled heaters. We have electric towel heaters in the bathrooms which come on for 1/2 hour in the morning so far only to help dry towels rather than to heat the space. We are delighted with how well it is working. We have had to do some extra draft proofing on the doors with some silicone sealant which has made a bit of a difference. Attention to detail from your builder is key to seal the house really well.

  • Anonymous

    Thanks to all of you who responded – it’s very re-assuring and gives us the confidence to move on with our plans. I should have pointed out that we intend to install a whole-house MHRV system, and will have electric under-floor heating in both bathrooms. On the basis of your advice, we will consider a slightly larger wood-burning stove and possibly electric under-floor heating in the kitchen area (but I’ll seek further advice on these points).


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