• Blackhouse Model for Green Homes

    by  • 22 October 2008 • Archaeology, Health & Food, History, Life in Uig • 1 Comment

     An article by Mary Beith, first published in the Scotsman in July 1990.  Thanks to Mary for the opportunity to republish it.

    A group of architects and others at Manchester University who had been devoting a great deal of time and thought to devising the environmentally ideal house of the future were understandably well pleased with the outcome of their researches.

    That home would be long, narrow and rectangular, easy to span – thus cutting down on timber – highly insulated and with minimal windows; it would be a single volume house, not a series of separate rooms to ceiling level but divided by two-metre high partitions where the air could circulate freely above; and there would be a centralised heating source.

    When one of the group contacted Bruce Walker, a lecture in architecture at the Duncan of Jordanston College and Dundee University, now on secondment to Historic Buildings and Monuments, the latter listened with not a little quiet amusement to the list of specifications for the ultimate in green homes.

    “What you have just described,” he told his informant, “is a Western Isles black house – without the peat smoke.”

    They have tremendous advantages, says Dr Walker: “Especially in that they were so much easier to heat with 100 per cent energy efficiency from the central fire which could generate the equivalent of 7 kilowatts. Later island houses had gable hearths with only 18 to 20 per cent efficiency with the bulk of the heat going out the chimney and even a modern stove is only 65 per cent efficient.”

    Careful experiments with plastic models, incense and lightbulbs have proved not only the energy conservation qualities of the blackhouses but also the ingenious methods of their builders. That very peat smoke had its uses and there were ways of avoiding its disadvantages.  The uneven-looking roofs and somewhat ill-fitting doors were not, Dr Walker had found, the results of haphazard and shoddy workmanship but a clever way of setting up convection currents caused by the heat given off by the cattle in the integral byre.

    Those currents acted against the smoke coming from the living end of the house by forming a warm air curtain that prevented smoke passing beyond the entrance lobby, where the roof dipped, and affecting the livestock.

    However, visitors in recent years to the preserved blackhouse at Arnol on the west coast of Lewis, an object of particular study by Bruce Walker, may not have found its byre a particularly smoke-free zone.

    That was no fault of the original builders and the matter is being put to rights with complete re-roofing and thatching.  Advisers to Historic Buildings and Monuments, who took over the house at 42 Arnol in 1965, believed that the then low pitch of the byre room was the result of some failure and accordingly adjusted the height of it in line with the rest of the building.

    Older locals, however, constantly jibbed at the inaccuracy of the reconstruction and Bruce Walker’s recent researches have confirmed their opinions to “official” satisfaction.  (Always listen to the well-informed local is an axiom that should ever be borne in mind.)

    As HBM has now admitted: “The low pitch was a design feature calculated to prevent the penetration of smoke into the byre area when the cattle were in residence.”  At the same time the smoke in the house acted to keep down fungal growths and insects and prevented the timbers rotting.

    In the living area the smoke level was always at least three and a half to four feet off the ground and that was countered by using chairs and settles with especially low seats – if chairs were brought in from the mainland, suitable lengths were simply sawn off the legs.

    “People were working outside all day and just used the houses for eating, sleeping and shelter,” says Dr Walker. “There are records of Bonnie Prince Charlie insisting on having a higher chair than his subjects when he was hiding in the Isles and, of course, he ended up coughing and spluttering.”

    In earlier times the very thatch of the roof itself was a forerunner of our own new philosophy of recycling.  When the house was re-thatched, the old, nutrient-rich heather and straw, heavily impregnated with smoke, made and excellent fertiliser for the tattie patch.

    Often oblong, with rounded rather than strictly rectangular corners, the houses could be up to 60 feet long with walls five or more feet wide – the black house or taigh dubh constructed of drystone walling with earth infill being so named to distinguish it from the later “white” house or taigh geal, with its cemented stones.

    “Over it,” Bruce Walker explains, “the roof was pitched to 45 degrees at the living end, then to 25 degrees at the entrance and was only 11 degrees at the furthest end of the byre.  The doors, originally of wattle and later of timber, didn’t fit on purpose – allowing free circulation of air which helped to winnow the stores at the barn at the back.”

    Yet Chrisetta Smith, the third generation of her family to act as an official custodian for the house her ancestor built, although she lives in a modern house nearby, will tell you the living quarters are draught-free.

    “I can’t ever hear the wind when I’m in the black house even if there’s a howling gale outside.”

    As for the dampness, that was an affliction of abandoned, not the inhabited, blackhouses.  Stories about never letting the fire go out were not mere superstition.

    “There is never any damp when the fire is kept going,” says Mrs Smith.  “The floor is always quite dry because the heat of the fire on the stone floor spreads out and radiates through the house.  At night we bank it up.”

    There are drains of stone and clay underneath the floor to divert the numerous springs in the area.  Underfloor drains, as noted in the guidebook to the house, have a long history and are to be found even in neolithic houses like the ones at Skara Brae.

    At one time byre dwellings were common all over Europe and the Western Isles designs are scaled down replicas of the very large Friesian and Netherland farm buildings.  Other similar houses are found in Western Scandinavia, Iceland and the Faroes.

    “It’s a plan that’s been around for a very long time,” says Dr Walker. “The Arnol type is very similar to one excavated in Newfoundland and dated to 1000AD.” Yet other designs are reminiscent of the even earlier figure-of-eight Pictish house at Buckquoy in Orkney.

    For the specialists at Manchester University to have re-invented them – minus the peat reek and the cattle breath – as the houses of the future is something to conjure with on dark nights round the decorative but energy-wasteful gas fires.

    ©Mary Beith

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    One Response to Blackhouse Model for Green Homes

    1. 13 January 2009 at 8:15 pm

      just what i was looking for!!!!!!BRILLIANT.We are planning the restoration of the old blackhouses on our croft in Bernera. a very helpful article. THANK YOU

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