ETFE foil cushions

Technical / General information:

Architect: RTKL
Engineer: Arhi.pro
Main Contractor: Eagle Hill
Membrane: ETFE foil-cushions
Steel Contractor: Jedinstvo Uzice, Serbia

Project

BW Galerija Shopping Mall is one of Serbia's newest attractions. Located in the Belgrade Waterfront 'district' on the banks of the River Sava, BW Galerija is also the largest shopping mall in Serbia and has already been a recipient of the "Concept & Design" award in the retail category at SEE Real Estate Awards 2017. BW Galerija is home to outstanding retail facilities with both international and local brands, a state of the art 12 screen cinema and exciting dining opportunities. It offers a much needed recreational area for the residents of Belgrade and visitors to the city.

Architects and engineers from RTKL and Arhi.pro wanted to replicate the existing street grid of Belgrade within the mall. The ambitious design incorporates a series of "open" internal public streets covered in ETFE cushions that create an instant connection between the mall and the beautiful waterfront along the Sava River. ETFE cushions are very lightweight and as such require significantly less supporting structure compared to heavier glass roofs, which added to the aesthetic that the architects wanted to achieve. Temme // Obermeier was appointed by the client as nominated subcontractor to the Main Contractor, Gradina to complete the detailed design and install the seven ETFE roofs with 186 cushions in total. As with all tensile architecture projects, one of the main challenges during the planning stage is to define the curvature of the cushion roof required to absorb the horizontal tensile forces and determine the foil thickness and the seam layout. As a rule of thumb, the higher the curvature, the lower the associated horizontal forces exerted on the structure. The cushions are pneumatically prestressed with a continuous air pressure of 350 Pa. The beautiful 46-meter transparent domed roof is a fitting entrance to BW Galerija.

ETFE fluoropolymer foils have a low coefficient of friction and Temme // Obermeier recommended the pitch required to aid the self-cleaning of the cushion roof, the rainwater will wash off dirt down from the highest pitch of the cushions. We used a print with a special silver reflective ink on the inside of the top film to prevent solar gain and ensure comfortable ambient temperatures while simultaneously allowing daylight to flood into the space reducing the need for unnecessary artificial lighting.

After only 7 months of assembly, Temme // Obermeier successfully installed the final ETFE cushion in December 2019 making the building watertight two months ahead of schedule. The excellent quality of the load bearing structural steelwork with precise layout of T-saddles provided by Gradina played aided the fast installation of the ETFE cushions. We are particularly proud to have completed this project well within the agreed time frame. This quick installation meant that the adjacent trades could get on with the internal finishing to the satisfaction of our client, Gradina. https://www.to-experts.com/en/membrane-construction/membrane-roofs/etfe-foile-cushion-roof/

Another unexpected highlight for us during this build was the excursion of around 200 architecture students from the University of Belgrade to site in October 2019. During this visit, Temme // Obermeier was able to showcase the advantages of ETFE membranes live - and the students also had the pleasure of seeing our dedicated installation team in action. Our installation teams are incredibly flexible and went far beyond the call of duty to ensure that we finished the roof two months ahead of schedule.

Belgrade Waterfront and BW Galerija by Eagle Hills are impressive additions to the city and economy of Belgrade and each visit promises to be an extraordinary shopping extravaganza. You can find the movie of the opening of Galerija Belgrade here: https://www.to-experts.com/en/company/publications/movies/