SUSTAINABILITY WAS A KEY FOCUS IN THE DEVELOPMENT OF BESTSELLER’S NEW DISTRIBUTION CENTRE. THE AMBITION WAS CLEAR: TO CREATE A DISTRIBUTION CENTRE THAT WAS AS SUSTAINABLE AS POSSIBLE. CONSTRUCTION IS INEVITABLY LINKED TO THE USE OF RAW MATERIALS AND THE PRODUCTION, PROCESSING AND ASSEMBLY OF MATERIALS, WHICH RELEASE CO₂. AS CO₂ PLAYS A SIGNIFICANT ROLE IN GLOBAL WARMING, THIS PROJECT HAS DELIBERATELY SOUGHT WAYS TO OFFSET THESE EMISSIONS BY STORING CO₂ WITHIN THE BUILDING.
Bio-based materials play a key role in this. Materials such as wood and straw store CO₂ as they grow. Straw is a by-product of the grain harvest that is normally often burnt, causing the stored CO₂ to be released back into the atmosphere. By using straw as insulation material in the façades, this CO₂ remains stored for the long term and a low-value by-product is given a high-value application in construction.
PREFABRICATED STRAW MODULES
Prefabricated straw modules from Ecococon in Romania, the Czech Republic and Ukraine were chosen for the façades. These modules consist of a wooden frame into which straw has been compressed under high pressure. Each module is 400 mm thick and, due to production constraints, has maximum dimensions of 800 × 3,000 mm. The modules formed the building blocks for all the façades of the distribution centre.
Contractor Van de Ven transformed the straw modules into complete façade elements by constructing a structural framework of CLT and LVL timber, into which the modules were incorporated. The façade elements were fitted with fire-resistant cladding on both sides and then installed on site as prefabricated elements.
STRUCTURAL CHALLENGE
For Pelecon, this innovative façade presented a number of specific challenges. Pelecon designed and detailed the connections and joints between the timber façade elements and the timber, steel and precast concrete main supporting structure. This involved close coordination with the manufacturer Ecococon and the contractor Van de Ven to ensure structural safety, manufacturability and feasibility.
The relatively thick, bio-based façade elements also required careful coordination of the structural design, façade construction, detailing, fixings, deformations and prefabrication. It is precisely with innovative construction methods that an integrated approach is essential to reconcile structural safety, feasibility and sustainability.
THE RESULT
A total of approximately 40,000 m² of Ecococon cladding was installed, an exceptional scale for a project involving bio-based façade construction. Due to this scale, the production of the straw modules at Ecococon took over a year.
The result is an innovative façade construction in which an agricultural by-product has been transformed into a high-quality building material. By not burning the straw but incorporating it into the façades for the long term, a significant amount of CO₂ is sequestered and the façade makes a direct contribution to Bestseller’s sustainability ambitions.
THAT LITTLE EXTRA
For Pelecon, this project demonstrates that structural engineering advice goes far beyond simply sizing a load-bearing structure. By actively contributing ideas on material choices, manufacturability, detailing and collaboration between the manufacturer, contractor and structural engineer right from the initial design phase, Pelecon helps to deliver innovative and future-proof construction solutions. It is precisely in bio-based projects that the strength of integrated structural design really comes into its own.