The Arboretum project, on the banks of the River Seine at Nanterre, near Paris, will provide 125,000 square metres of office and service space and is almost entirely timber-framed. The client is a consortium of developer WO2, property investment fund Icawood and Canadian developer Ivanhoé Cambridge.
The cross-laminated timber components are supplied by Finnish specialist Stora Enso.
The €650m (£557m) development comprises five buildings, each of which will be named after a tree: Almond, Pine, Cedar, Fir and Spruce. A park, a fruit and vegetable garden for the use of campus restaurants, and two renovated industrial buildings will complete the development.
The campus is supposed to maximise exposure to the natural environment, allowing employees working there to relax and concentrate better.
Measures designed to reduce the site’s carbon footprint include the reuse of materials, ‘bioclimatic’ architecture and a geothermal system that will satisfy up to 80% of heating and cooling requirements.
Liebherr is doing all the heavy lifting for the main contractor, GCC. “We opted for Liebherr cranes because of our longstanding business relationship,” says Antonio Silva de Almeida, site manager for GCC.
The 10 top-slewing EC-B series cranes are closely spaced and have to be carefully coordinated with each other to avoid clashing.
To ensure this, all cranes are equipped with an anti-collision system supplied by French manufacturer AMCS Technologies. The cranes are also equipped with Liebherr’s LiUP operator lifts.
The LiUP system is designed to carry two people or a maximum load of 200 kilogrammes. It gives crane operators quick access to their workplace and spares service engineers a strenuous climb during maintenance work.
“The cranes are reliable and powerful, and the LiUP lift ensures a high level of safety,” comments Silva de Almeida.
GCC is operating two 220 EC-B 10 cranes, two 250 EC-B 10s, one 250 EC-B 12, two 285 EC B 12s, two 340 EC-B 12s and one 370 EC-B 12. The largest of the cranes can lift a maximum load of 12 tonnes.
Jib lengths vary between 47.5 metres and 60 metres and hook heights range from 41 metres to 59 metres. As a result of these configurations and their flat-top design, the cranes can slew above each other without fear of any collision. The AMCS system monitors hook positions and prevents jibs from interfering with suspended loads.
The Liebherr cranes are being used for positioning timber and concrete elements such as posts, beams, columns, staircases and lifts. The Arboretum project involves the erection of 20,000 cubic metres of engineered wood components and the placing of 55,000 cubic metres of concrete.
The lifting operations are controlled by Liebherr’s Micromove fine positioning system, which positions components with precision to ensure accurate load placement and avoids any risk of damaging delicate components or surrounding elements of the construction.
Most of the cranes are new machines that GCC has hired in under a leasing agreement with Liebherr-Grues à Tour, the manufacturer’s French subsidiary. “Leasing means that customers always benefit from the latest cranes,” says Sébastien Chalvet, Liebherr’s key account manager for the Île-de-France region.
The cranes are also managed and maintained by Liebherr-Grues à Tour. “Working this way ensures that cranes are perfectly maintained for maximum availability, and that we can guarantee our customers the highest possible safety standards,” says Chalvet.
Spare parts are readily available from Liebherr’s parts warehouse in Fontenay-Trésigny, south-east of Paris.
Grow your own campus
Hailed as Europe’s biggest timber-framed complex, the Arboretum project is the brainchild of French firm WO2, an integrated property developer launched in 2014 and specialising in the development of buildings made from cross-laminated timber (CLT).
WO2 claims that, over its cradle-to-grave lifecycle, the development will emit 47% less carbon into the atmosphere than if it were built using conventional materials.
The CLT elements, supplied by Finnish firm Stora Enso, are said to contain around 15,500 tonnes of carbon, absorbed by the timber during its growth. And it makes the remarkable claim that “less than three hours is the amount of time it will take for the wood in the CLT provided by Stora Enso to grow back in the Austrian forests on a summer day.”
Other sustainability claims for the Arboretem project include 80 tonnes of on-site organic waste transformed into 16 tonnes of compost per year and 20,000m3 of drinking water saved each year through the use of rainwater harvesting.
A 3,200m2 vegetable garden and orchard in the grounds of the development is expected to produce 10 tonnes of fruit and vegetables every year.
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