22 Building for a Future Winter 2002/03
Lothian gridshell
Gridshell is in vogue. BFF has featured at least two other gridshell projects over the last year. Previous projects have portrayed the method as a highly technical use of a low tech resource. This, however, need not be the case as we see with this project - the new home of the Life Science Centre Trust. Oliver Lowenstein reports...
Lothian Gridshell
Building for a Future Winter 2002/03 23
Today, two buildings rest within the Centres grounds. The rst,
a timber-frame barn off to the edge of the Trusts land. The
other is a craft centre near the entrance, with signs of continu-
ing workmanship everywhere around; unstacked timber, builders tools
and materials. The building is almost complete. It sits easily under the
pine bowers, log columns on each side, and grass roof and stone walls
providing a deeply organic, quasi-rustic feel to the building as bets
the work of its architect, the respected Christopher Day. But it is upon
hearing about the heart of the building - the craft room, that ears have
been perking up, for its roof is a ten metre span self-built gridshell,
constructed entirely by the craftsmanship of working hands. News
of the gridshell has already leaked out into at least one mainstream
architectural journal. The other gridshell Riba magazine announced
months ago, immediately setting off comparison to the recently opened
and widely praised Weald and Downland
Museum gridshell in Sussex. There are
comparisons to be made, both are, after all,
gridshells. But in reality both are completely
different buildings constructed from related
but different mindsets. The Weald and
Downland gridshell is a notable achievement,
but it has been completed with international
architectural and engineering practises and
equally international level funding resources.
If you happen to have a spare 1.8 million
you too can build a gridshell of the scale
and dynamism of Weald and Downland, but
it doesnt need this writer to reiterate that
most organisations dont have that kind of
depth to their pockets.
This means it is out of reach of many in
the community who might want to explore
such forms at an equally valid if far smaller
scale. Which is where the Pishwanton
building (although it is beginning to be
known as Lothian gridshell) comes in.
Through what appears as a mixture of forti-
tude, foolhardiness and staying power, the
Pishwanton building has been completed over four years in a stop-start,
almost hand-to-mouth fashion. It is testimony to those involved that
against the kind of odds where more mainstream professional opera-
tions would have not entertained being involved, the Life Science Trust
has seen the project to completion. And they have done so at a cost a
fraction of its giant cousin far to the south between 50 and 60,000
- considerably inside the grant released by the Heritage Commission just
to begin the Weald and Downland gridshell reseach.1
Pishwantons story began with the founder of the Life Science
Trust, Margaret Colquhoun. A committed Anthroposophist2, Colquhoun
had, for many, years nursed the vision of creating a centre dedicated
to developing the work of Goethian life science.3 In the run-up to
the Millennium with Lottery and other money suddenly available she
appears to have seen a way of making it happen, or at least begin-
Top left: internal view of nished grid Above: nished turfed roof of central space Left: modelling of grid
Photos by Tasker/Lowenstein
24 Building for a Future Winter 2002/03
Lothian gridshell
ning on her dream. After some preliminary on site work
by a local architect, Richard Shorter, Colquhoun enrolled
Christopher Day, the best known of a small band of
Anthroposophical or Steiner architects in this country, and
a revered inuence in certain segments of the architectural
rmament. Colquhoun and Day had already begun working
together right from Pishwantons inception. Even before
the land was purchased the two would go to Pishwanton
to, as Colquhoun puts it, listen to the land, applying
the same intuitive approach which Goethian Science
uses to try and sense what the land wants, and indeed in
their view, whether it was actually the right place for the
Centre to grow from. Colquhoun points out that her and
Days approach are in fact inseparable. As it was listen-
ing to Pishwantons landscape, its genius loci, extended
to everyone involved, and worked through a number of
stages aimed at heightening the senses to the atmos-
pheres and moods of the place, which in time resulted
in becoming aware of where exactly and what forms the
buildings would, as it were, manifest. This communal and
apparently all-inclusive approach is what Day means by
Consensual Design, enabled by a process of opening to
the environment. In fact Day would not claim the build-
ings are his, rather he expresses what those participating,
in their sensing of the place as a living animate entity, say
is needed. Such an esoteric process-led approach mat
appear bizarre to even the environmental building sector,
or at least those who nd it difcult to give credence to a
living, vitalistic environment. So it was out of this intui-
tive precognition that the building projects at Pishwanton
grew, initially three buildings, but as various funding constraints began
to bite, the focus turned to the craft building.
Day began sketching out the architectural ideas in 1997, using local
engineers, although design continued throughout the rest of the year
and into 98. At the same time Colquhoun did the landscaping, based
on the same Goethian Science principles. Originally, the rst of these
was going to be, symbolically, the Seed building, out of which the
other buildings would grow. But the Seed building needed 900,000
to make it happen, and although there was funding of sorts it wasnt
on this scale.
The nance there was came in the form of National Lottery
funding, a three year start up, plus other donations, some in kind,
some in money. With nancial support, but not enough to begin the
Seed building, there was a sense that a beginning needed to be made
somewhere, so attention turned to the craft building. The rst work was
begun by Malcolm Lemmon, a local forester and builder in residence (as
well as sawmiller and joiner). The building is to provide both sheltered
facilities for Life Science Trust activities in bad weather, and for pottery
classes, wood carving and other woodland crafts.
Initially work went well, but in 1999 things began to become
muddled. Completing the building was nowhere in site. The local
engineers were proposing an apparently sophisticated but prohibitively
expensive truss system, which would apply beams and columns to
the central area. Although interesting, it would have needed a very
extensive, and costly amount of timber. It was at this point that David
Tasker, a structural engineer well known both in and outside the Steiner
movement, who had already been involved was brought in to reassess
the situation. And Tasker, upon seeing the column planned, thought
this wants to be a gridshell.
The resulting plan envisaged three pod-like gridshells resting on an
Building for a Future Winter 2002/03 25
irregular hexagon, nine metres in diameter. Today on each side of the
completed hexagon room, are two wings, one for storage the other
comprised of two smaller rooms.
There was limited structural analysis, which Tasker describes as
backyard engineering, mainly scaled modelling and basic shell
theory, but without the usual fancy software programmes; a full 3D
structural analysis wasnt applied both because of uncertainties over the
wood and the prohibitive cost. Tasker also acknowledges the jointing as
very basic - partially as a result of its computer independence. However,
for Tasker what has emerged is a unique organic building.
Apart from the wood used in the gridshell, beams and truss, the
building used primarily locally sourced limestone, sand, and wool. No
Portland cement was used at all; a Colquhoun stipulation. In its place
jura limecrete was imported for the foundations, and as mortar for the
stone walls. Given the commitment to being as ecologically benign
as possible, as well as its relative expense, bringing in this specialist
limestone from half-way across Switzerland may appear quixotic, but
within the lime community it is generally considered amongst the best
of limes, with a very low embodied energy. Recommended by Douglas
Johnson of Masons Mortar (a limesman extraordinaire quoth David
Tasker) its characteristics include its strength and quick rate of curing.
Also given that the Scottish have a predilection for using lime, its use
isnt a complete surprise. A second, St Astier lime, this time from France,
was applied to all the above ground walls. The walls were built up by
a contracted stonemason from local stone brought in from a farmers
old dry-stone wall a handful of miles along the hill ridge. The sand used
was from the local quarry. Mineral wool was used in the external walls
and cavity walls, whilst in the other openings sheep wool was used.
Marketed as Cosywool, it came from the Wool Marketing Board; being
made into tops on site, small long sausage shapes cut from 100 metres
of the material. The work took time having to repeatedly
fold the wool over, but was pleasant on the hands - unlike
many comparable glass and mineral wools.
At rst, admits Lemmon, he was sceptical about
gridshells. They didnt appear to follow the way the wood
wanted to go, rather, it seemed as if the form was ghting
against nature. But soon the challenge got the better of
him, and quite quickly the technical problems of realis-
ing the project, apart from delivering mighty headaches,
became fascinating issues with which to wrestle and nd
solutions to.
He found 40 tonnes of larch from a Steiner project in
Perthshire, which had oundered and was closing down.
Lemmon bought this after checking its sustainability
factors. The timber for the window frames was Highland
Douglas r - an increasingly popular, and durable,
tree crop in Scotland - manufactured into windows in
Edinburgh. The alternative, oak, was too costly to have
been considered within the spartan budget.
The work was carried out, evolving and creating, as the
team went along, fresh drawings and sketches frequently
arriving, so as to integrate new and added-on ideas. For
Lemmon, as for all those centrally involved, it was a steep
learning curve. What analysis there was happened on
site as the building progressed. Happily, once construc-
tion was underway the roof turned out to be not as
difcult as Lemmon had presumed it would be. Tasker
had prepared a small experiment with a miniature pine
dome model, and Lemmon used this to see how the wood
would respond. From this he realised that young green
26 Building for a Future Winter 2002/03
Lothian gridshell
larch would work well; the saps elasticity ensuring the bending needed for the
curvature. From there, Lemmon went looking for the right potential larch, nding
it eventually in one of the Earl of Roseberys estates forests, a few miles south
of Edinburgh. Trained to be able to uncover woods from eye, he hand-picked the
larches, and took them away as part of a management thinning project with the
estate. These were prepared as laths around four metres long, and next, initially
by trial and error, Lemmon began constructing longer laths, scarf jointing three
together to make twelve metre lengths, until there were two sets of 20 laths, able
to cover twelve metres. These were made up in two layers of 35mm by 25mm by
600 cm squares, with the bits drilled in to form the nodes. These were checked
using pilot bolts, on the jig, to hold each square of the grid together.
Once it was ready, the grid was put together and bolted up in one day,
with nearly two dozen volunteers helping at the site, including many disabled
adults from a local Steiner Camphill community. It must have been quite a sight
watching Lemmon choreograph twenty or so people as they inched forward up
a specially constructed ramp. Two hours later the volunteers had manoeuvred
the grid into position as part of the roof, an inch too far and the fresh green
larch could all too easily break. In the event only two joints needed replacing.
Completely oppy, the gridshell was at this point both very supple and fragile
until the boards covering the laths were also put in place. After this further
boarding was applied, and the structural shape formed around a scaffolding
tower and temporary timber struts.
While the corners were held down by rope, the rst two layers of 100mm
boards were screwed into the lattice, the shell, according to Lemmon, becoming
more uniform, as it began to dry out. The board wood was found from a local
forest four miles away, an economic choice since this was small enough to be cut
into shape. In fact the whole gridshell cost was minimal, Lemmon believed the
fasteners for the roof came to 350, and the boards less than that. The whole
gridshell was in region of 2500, although as Lemmon points out that when you
add labour, his work and two intermittent paid helpers, it inevitably increases
the cost. As it was put into place, each layer of boarding soon reinforced the
emerging shape. Alternate layers were placed at 90 degrees to each other, to
reinforce the strength. With
three layers across the whole
dome, and four at the edges
this produced an effectively
extra-tough roof. An extra
complication was that the
shell was being placed onto
the hexagon. Domes have
been placed on square and
circular rooms, tting these
proportions easily, but they
have not been sat upon
hexagons. Not surprising,
perhaps, as they do not t so
readily. Lemmon pulled the
gridshell dome down upon
the two opposing sides of
the hexagon walls initially,
until they began to bend into
shape. Once the gridshell
dome and boarding was in
place it was covered with a
turf roof, and the Rubberfuse
membrane was sourced as
the best eco-friendly option
available. Insulation contin-
ued to be a problem and
cork was eventually applied
to the membrane. The cork,
another import, this time
from Portugal, compared well with polyutherene and other polyester insula-
tions. A cob wall was designed for the right hand side of the entrance, and this
late feature is currently on the verge of being passed by East Lothians building
and planning control ofces. At the same time the oor is suspended above
the ground, enabling the full ventilation system to work. The roof was nally
completed at the beginning of the year, being covered with horse and cow dung,
and presently sports a thick grass matting.
Before it went up, no-one knew whether the gridshell would actually work
and although Tasker felt condent there wouldnt be any real structural problems,
there were quite a few nerve-wracking days wondering what they were going
>>>>
28 Building for a Future Winter 2002/03
Lothian gridshell
to say to the funders if it didnt. Unsurprisingly, the load testing was
unconventional. Rather than computer analysis, the building group
hand calculated 700 bags of sand which when massed equalled 13.4
tonnes of sand, so that the deection on the roof could be carefully
measured it came in at 25 millimetres, equalling the worst snow cover
scenario.
Work out it did, however, and in the summer of 2002 it began to be
used, even if it needs some nishing off. As such it represents a success
story for the small-scale and self-build, and it also demonstrates some-
thing of the tenacity of a small team. One can easily speculate that
were local building contractors let loose on such an unknown quality
as a gridshell, given so few have any experience of the form, let alone
have worked on one, they would price the risk
into budget oblivion. Since only one or two
companies have the relevant experience, this
must be one of the main constraints on its
growth in use, with specication and design
generally so expensive. The Pishwanton
gridshell demonstrates that with resolve and
patience people can construct for themselves.
All those involved state there were a variety
of things learnt, and could improve on it if it
was being constructed again. What would
be helpful is a further step by the team to
make available the step-by-step approach
for anyone interested. This would show
possible contractors some of the pitfalls and
begin to bring the prospective price into the
realm where anyone could, in theory, build
a gridshell. Certainly such smaller-scale
applications seem obvious. Gridshell pod
roofs could be used for 10 m classrooms both
in, and outside, the Steiner-Waldorf context.
Their further uses in a variety of contexts are
also easy to imagine.
One real surprise is that gridshells were
new to Day. Even if there are very few,
they suit his Spirit and Place aesthetic,
as expressed in his book4, very well. He
believes the double-curved parabolic form
contains considerable strength, and describes
the internal space as a very gracious and
harmonious gesture. All of which helps make
the form so satisfying, in Days words, at
a preconscious level. Tasker himself came
across gridshells in the seventies, when he
was a student at the Bartlett with the German
Architect, Florian Beigel, who today runs the
Architectural Research Unit at North London
University School of Architecture5. It is a
footnote of architectural history that Beigel
was instrumental in bringing gridshells to Britain. He came to Britain
from working with Frei Otto on another of the renowned Germans
gridshells, the Munich tent structure. This was a cable grid structure,
in contrast to Mannheims compression structure. Originally, Otto had
uncovered the possibilities of gridshellls by observing the biological
structure of double-curved coral, a textbook example of nature as a
strategy for design. When he came to Britain in nineteen seventy, Beigel
brought the gridshell concept with him. In 1974, along with his students,
he constructed a series of four gridshell structures on Highbury Fields
as experimental exercises. From there he tried to get funding support
from Arups and then Happolds to continue the research, just when
the two big engineering companies were rst beginning to research
Building for a Future Winter 2002/03 29
tension structures, but to no avail. The Highbury Fields gridshells are
documented in one of the Stuttgart Institute for Lightweight Structures
booklets6, although Tasker recalls coming upon the form through a
brochure that Beigel published. Tasker found what he was looking at
very refreshing. Similarly Beigel in conversation, although not directly
involved in gridshell design for a number of years, to this day remains
absorbed by its simple elegance. Despite being double-curvature forms,
the use of laths makes for a very simple element. Usually such double-
curvature is difcult and the manufacturing expensive. I still nd the
elegance of the idea very fascinating, Beigel says. With wood there
was, for the rst time, a way of making the square of the form into a
parallelogram. He is also, as with Day, attracted to the gentleness of
the structures form, with its soft curves, compared to the tent gridshell,
with their lofty peaks. Given these curves Beigel feels certain of a
connection to the human body. It is very much a bodily relationship
he believes. His last direct involvement in the form was in 1992 when
he was centrally involved in plans for a gridshell theatre and arts centre
in Brentwood, Essex, it never got any further however. Were it to have,
the beginnings of this gridshell movement might have been earlier
off the starting block. By this time, the inuence of the Mannheim
building on the two Teds, Cullinan and Happold, was already water
under the bridge, an inuence Beigel helped along. He also notes that
Mannheims project engineer, Ian Liddell, was actually British. Today,
he points out the Weald and Downland gridshell is exactly the same
shape as the structures he and his students were playing around with
on the playing elds near-on thirty years ago. The difculty remains
with the decking, with its borrowed boat-building technique, and impli-
cation of hours and hours of craft input. As he says the actual structure
is straightforward and easy.
It is the spores of Beigels journey to Britain with the gridshell
fresh in his imagination and the subsequent exploration on Highbury
Fields, which is a primary inspiration for all three gridshells, which
have emerged during this millennium time. Last summer, the Weald
and Downland gridshell opened, and at a celebratory conference in July,
Time for Timber, it again reminded one what a remarkable building
it is. It did, however, also remind one of its exceptional showcase
nature. Whilst one cant but hope there will be further opportuni-
ties for such grand schemes, Tasker and Days smaller relative, way
up north, suggests that gridshells can also come in many varieties,
small and perfectly formed, as well as large-scale. At the Time for
Timber conference the word optimism close to the word wood was
on many peoples lips. The sense that the resurgence of wood is on
the cusp of a new growth, was underlined there, and that the Weald
and Downland gridshell constituted a springboard, so to speak, from
which this resurgence could develop. In fact it forms a midpoint in a
short triadic necklace of related buildings; Frei Ottos 90s Hooke Park
Workshop to the west in Dorset, and to the east, the smaller adapted
Flimwell Woodland Centre Chestnut gridshell. Even if Hooke Park is not
a gridshell, it belongs to the same family. One might also mention that
Gensler designed a four-double gridshell building, for a Home Counties
nancial services trading extension, but in reality this in a different
category, sharing neither the rural context, nor the ecological or craft
concerns of the other buildings. There is much that could grow from
this belt of projects, potentially stimulating a further generation of
such buildings over the coming years. And with the Pishwanton Lothian
project complete, a fourth family member brings another, accessibly
small-scale dimension to the growing band of buildings, which are
pulling this genuinely exciting, elegantly ecological and twenty-rst
century form into material existence.
Oliver Lowenstein
Refs:
1 Putting this in some context, this budget would hardly have paid for
all, or even much of the worktime of the complete team, if this had
been at the heart of the matter. At Weald and Downland, much of
this initial research budget apparently went on prototyping and timber
testing.
2 Anthroposophy is a spiritual philosophy founded by the twentieth
century thinker and mystic, Rudolf Steiner. Best known as founder
of Waldorf or Steiner schools, Steiners philosophy extends to many
aspects of life, including a specic approach to architecture. There are
anthroposophical architects throughout many parts of world, although
the majority are found in Europe, with a small number working in
Britain, the best known being Christopher Day.
3 The Goethian approach is one element at the heart of holistic
science, and is based around the qualities of the observation of the
onlooker on the subject of study, invariably, though not inevitably, the
processes of nature. Although contemporary Goethian science has a
variety of strands, if it is immediately related to any twentieth century
movement, it is that of the Anthroposophy of Rudolf Steiner, founder
of Waldorf or Steiner schools, and scientist of the invisible, whose
spiritual philosophy has been described as a resurrection of Goethes
scientic impulse, although Goethe is better known as the father of
German romantic poetry and literature.
4 Spirit and Place, Christopher Day, Architecture Press 2002
5 See www.aru.unl.ac.uk
6 IL13. Institute of Lightweight Structures, Stuttgart, Germany
Oliver Lowenstein runs the green cultural magazine, Fourth Door Review, www.fourthdoor.co.uk [email protected]
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