Timber gridshells
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[edit] Early historical precedents
Whilst perhaps not always listed in relationship to gridshells, it is worth mentioning some of the earliest forms of vernacular dwellings that in many ways maintain strong connections with and often formed the inspiration for what have come to be known as timber gridshells.
It is believed, through carbon dating of a structure found in Moldova and in parts of Russia, that circular dome-shaped dwellings made from branches and animal bones covered in hide were used by Neanderthals and early humans as early as 40,000 BC. There is some evidence that suggests that cone-shaped tipi dwellings may have been in used as far back as 10,000 BCE. The Bedouin stretch tents date from around 6000 BCE, as they engaged in nomadic herding and agriculture in the Syrian steppe, with larger settlements forming around 850 BCE. Finally, the sarifa, raba and mudhif structures dating, possibly earlier than 3,300 BCE (which is the date of a depiction of a msudhif found in Uhruk, later called Babylonia, in Iraq). These structures were made from bent and bound reeds (ihdri) to form parabolic arches which make up the building's spine.
(image credit: Mohamad.bagher.nasery Creative Commons Attribution-Share Alike 3.0 Unported licence.)
Celtic Iron Age round houses were not shell structures but resembled circular timber dome structures and were built between 1200 and 600 B.C. However the yurt, has possibly the closest resemblance to the gridshell typology first appearing in a carving on a bronze bowl, found in the Zagros Mountains of Iran in about 600 BCE. The Mongolian people called these structures ger (yurt is a Russian translation), in particular the horizontal walls of the ger, called khana were formed of latticed and collapsable timbers in tension. These criss-crossing wooden poles were made of light wood, such as willow, birch, poplar, or even bamboo and attached to each other with ropes made of leather or animal hair. The roof was made of straight poles laid from the top of the walls to a circular crown, which itself had a number of bent wood elements in tension, very similar structurally to the gridshell.
(image credit: Adam Harangozó Creative Commons Attribution-Share Alike 4.0 International licence.)
[edit] The first formal gridshells
It was the study of these primitive light efficient building types that inspired one of the prolific builders of both gridshells and tensile structures, Frei Otto, and thus his establishment of the Institute for Lightweight Structures at the University of Stuttgart. Otto generally chose timber as his material for gridshells, whilst steel, fabric and glass tended to be used for his tensile structures such as the stadium in Munich.
The first formal timber gridshell or gitterschale as he would have called them, was a trial he built was in the same year as he built a dome structure using steel rods at Berkley in 1962. He and some students used hemlock laths bolted together, creating what was effectively the first gridshell which then became the engineered gridshell building for DEUBAU German Building Exhibition at Essen, Germany in 1962.
(Image credit: Immanuel Giel Creative Commons Attribution 3.0 Unported licence.)
The seminal timber gridshell where Otto was actually invited as a consultant, was through a competition held in 1970 for the Bundesgartenschau of 1975 to be held in Mannheim. The architects Carl Mutschler & Partners and landscape architect Heinz H Eckebrecht were selected to design the Herzogenriedpark including a huge hall. The team collaborated at Atelier Warmbronn on wire mesh models, which were then re-modelled using hanging wire models which formed the final designs for the gridshell structure inverted.
Whilst the models had given an indication of form and structure the construction of the actual building had many unknowns and construction approaches were tested. The primary components were long timber laths in pars which were laid in a flat grid, then the structure was supported in position and fixed at the crossovers, whilst the boundaries were fixed to the ground base. The end result was a long sweeping and quite free-form structure held in tension. It was the centre piece of the event and although the structure was intended to be temporary it still stands today.
Later in 2000, although initially intended to made only from cardboard tubes, Otto collaborated with Shigeru Ban Architects and Buro Happold on the Japanese pavillion for Expo 2000 in Hannover. A temporary structure, it was built using lengthy paper tubing and timber struts. The final building was 73m long, 25m wide, and 16m high. Also as part of the same Expo the German Architect Thomas Herzog designed a wooden structural roof for the central piazza of lattice shell canopies covering more than 16,000 square metres.
(image credit Harald Bischoff licenced under the Creative Commons Attribution 3.0 Unported.)
[edit] UK gridshells
Following the Hannover exhibition one of the most notable gridshells to be constructed was in the UK, again a free-flowing gridshell structure which was made from green (freshly cut) oak laths - the Weald & Downland Open Air Museum gridshell. It was design by Edward Cullinan Architects, with Buro Happold engineers and built by the Green Oak Carpentry Company, completed in 2002 (sketch by editor).
The construction approach was very similar to the approach originally suggested by the contractors for the Mannheim gridshell. The paired grid of green oak laths were laid flat on supporting scaffolding, then over a number of weeks the edges were lowered gradually, as the green oak was more flexible this could occur with out breaking. This then slowly formed a three hump shell, which once in position was secured at the edges to a curved base frame, and the crossover junctions tightened with bespoke clamps, creating a stable tension structure which over time dried and seasoned, hardening to becoming a rigid curved building frame that was then clad in UK grown Western Red Cedar.
(Image credits: Copyright Janine Forbes and Clive Perrin licenced for reuse under this Creative Commons Licence.)
A second notable smaller gridshell completed in the UK one year later was the Flimwell Woodland Enterprise Centre Modular gridshell by Feilden Clegg Bradley, Atelier one engineers and In Wood Developments. The structure differed from the Cullinan building as it had a series of timber arched supports with gridshell lattices between. The building was innovative because it used small dimension coppiced sweet chestnut timber, finger-jointed into longer laths for the gridshell and also for the cladding.
(Image credits: Copyright Oast House Archive and licenced for reuse under this Creative Commons Licence.)
A third free-lowing UK gridshell was the the Savill Building visitor centre in Windsor Great Park, Surrey designed by Glen Howells Architects with Buro Happold and Engineers Haskins Robinson Waters again built by The Green Oak Carpentry Company in 2006. The building was constructed in the same way as the earlier Weald & Downland gridshell but this time using locally grown larch, it also used timber blocks between the paired laths and maintained a free flow external shape, without secondary waving upper roof.
(Image credits: Copyright Richard Humphrey and licenced for reuse under this Creative Commons Licence.)
[edit] Other examples
It wasn't until 2010 that other notable examples of timber gridshells started to be built with the Toskana thermal baths in Bad Orb, Germany by Fulda / Trabert Partners and Geis and Centre Pompidou-Metz by Shigeru Ban and Arup. Then both the Gridshell pavilion for Naples School of Architecture in the courtyard by Andrea Fiore, Daniele Lancia, Sergio Pone, Sofia Colabella, Bianca Parenti, with Bernardino D'Amico (Structural Consultant) and Francesco Portioli (Structural Consultant) and the pavillion in Selinunte’s archeological site by cmmkm architettura e design in 2012. The Elephant house in Zurich, Switzerland by Markus Schietsch Architekten / Walt and Galmarini and the Bamboo amphitheater space structure, in PUC Rio de Janeiro, design by Bambutec, both in 2014.
The Macallan Distillery Aberlour in Scotland by Rogers Stirk Harbour + Partners (2018) Triaxial gridshell using Eucalyptus by Lugo in Spain in 2018 and a number of others.
One of the most recent and possibly most impressive gridshell type buildings was not in timber per se but in bamboo and was completed on Earth Day in 2021. Engineers Atelier One worked with Ibuku and Jörg Stamm on the design of what is known the Arc - a community wellness space and gymnasium for the Green School campus in Bali. It is a complex buildings made up of a series of bamboo arch formed gridshellls, creating a dramatic flowing vaulted roof. It spans 23,5 metres with a height of 14 metres over a length of 41 metres.
--Editor
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Really thorough article thanks.