The igloo's apparently simple design masks an engineering marvel and
could teach modern builders a thing or two, says Dan Cruickshank, who
helped build one for his new TV series.
Last year I flew into the Arctic, heading for the east coast of Greenland. My plan was to see, indeed to help make, an igloo.
This inspirational and economic miniature-engineering marvel has long
fascinated me. How did the igloo evolve, when and where? No one knows
for sure but traditionally they were built only by specific Inuit
communities in relatively small areas of Greenland and Canada, and were
used only for temporary accommodation in winter months, or by Inuit on
hunting expeditions.
Dan Cruickshank with his igloo
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What's more certain, although perhaps surprising, is that the humble
igloo has a lot to teach the modern British house-builder. Last year, a
report by the government's architecture watchdog, Cabe, found more than
four in five new homes built in Britain since 2002 failed to meet the
needs of those who came to live in them.
By contrast, the design and construction principles enshrined by the
igloo are enduring and are a response to the essential reasons people
build - to create shelter from the elements and protection from danger.
Yet the way the igloo achieves these basic aims is ingenious and raises
it from a mere utilitarian structure to a piece of architecture. It is
not just a highly functional habitation but also a creation of
elemental beauty that's an intensely pleasing and perfect expression of
its function and manner and means of construction.
The igloo utilises what must be the potentially weakest of
building materials - frozen water - and gives this unlikely structural
material immense strength. Its domed form is not only a beautiful, and
in many cultures a sacred form representing the heavens and Divine
creation, but also a shape that is immensely strong.
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Dan Cruickshank's Adventures In Architecture is on BBC Two on Wednesdays at 2100 BST from 2 April
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Frozen water - snow and ice - also have other striking qualities.
It's the only readily cheap and available building material in much of
the Arctic and is, of course, an utterly renewable resource. It's a
construction material that causes no pollution whatsoever in its
manufacture, use or disposal.
This paradoxical material - weak in its nature yet capable of great
strength when used with intelligence - is the product of low
temperature but an incomparable insulator, so that an igloo excludes
external cold while retaining all the internal heat that is generated.
Consequently, an igloo can resist the onslaught of the most fierce
freezing gale, while its interior can be rapidly warmed by nothing more
than body heat and the flame of a blubber lamp.
Ice has it
I landed at a tiny airport and made my way, across frozen fjords
and pack ice, to the Inuit town of Ittoqqortoormiit to meet Andreas
Sanimuinaq, who would teach me how to build an igloo; how its dome can
be constructed with nothing more than a saw and without any need for
props or supports during the construction process.
Andreas Sanimuinaq, master of a dying art
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We boarded a sleigh and went in search of the correct, wind-compacted
snow needed for igloo construction. Soon we found the right place.
Andreas stamped out a circle in the snow - the plan of the igloo - sung
a song to dedicate the circular structure we were about to build to the
life-giving sun, and we got to work.
First we quarried blocks of snow - heavy brutes - and then
carried them a few meters to the construction site, located on the
snow-covered ice of the frozen fjord. The first three courses were
laid, block on block with sides nearly vertical. The igloo is not a
perfect hemispherical dome but more of an egg shape - in section a
catenary arch - which is about the strongest form in nature. Halfway
through the fourth course Andreas cut a wedge-shape block. This was the
key structural moment.
From here the blocks rose upwards in a continuous spiral - a
far stronger construction technique than placing course upon course
that allowed the dome during construction to be self-supporting. I also
discovered, as we worked, that blocks are held not so much by their
tailored form as by friction and freezing. Surfaces that are to be
joined are rubbed with the ice saw, the ice melts through the heat of
friction and the blocks are rammed and held together while the surface
moisture freezes, with the ice acting as mortar.
When we eventually completed the igloo I was able to enjoy the simple
but effective science of the design. Hot air rises while cold air
sinks, so as cold air lurked in the lower portion of the interior the
warm air - created by our body heat - rose into the dome where it was
trapped. We basked in this pleasant warmth while sitting on the high
snow-block and skin-covered interior bench. The igloo is indeed a
clever machine in which to live, for heat is balanced delicately
against cold - it's a structure in which nature is harnessed to tame
nature.
As water, caused by our body heat, trickled down the interior
surface of the igloo, it completely filled the joints between blocks to
refreeze during the cold of the night to form a grout between slabs
that excludes all drafts. This constant thawing and refreezing would
rapidly transforms the igloo from a house of snow into a far stronger
and windproof dwelling of solid ice.
Melting point
But Andreas tells me that igloo construction is a dying art. The
loss of the igloo is partly to do with changing culture - younger Inuit
prefer to live in timber houses flown in from Denmark, and have little
interest in learning the mystery of igloo construction.
Slotting ice blocks together
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But perhaps more alarmingly, the demise of the igloo is to do with
climate change. The area within the Arctic circle is now one of the
most rapidly warming places on the planet. Here temperatures are rising
nearly twice as fast as for the rest of the Earth and the permanent
sea-ice cover has declined by almost 40% in the past 30 years.
This means that building igloos in the areas where the Inuit live and
hunt is becoming increasingly difficult. Snow of the right consistency
is harder to find and it is ever more difficult to freeze blocks
together. The igloo has many lessons to teach, but tragically it seems
that it may not be around much longer to teach them.
BBC Magazine
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