Fereastra - Portal de afaceri - revista de specialitate pentru furnizorii de sisteme si producatorii de tamplarie din PVC, Aluminiu si lemn stratificat cu geam termoizolant. Aici gasiti informatii utile despre: ferestre, usi, pereti cortina, termopane, geam termopan, etc.

In many respects, Bromma Airport, located just a few kilometers from Stockholm’s city center, looks like a time capsule. Its authentic 1930s architecture, the compact, easy-to-navigate terminal and the short walks from the apron to the aircraft are still reminiscent of the exclusivity of that golden era of propeller aircraft.

 

The two distinctive main buildings, designed by Paul Hedqvist, have been listed as outstanding examples of Swedish functionalism architectural movement since 2000 and are of special architectural-historical importance. The original terminal building (Stationsbyggnaden) constructed in 1935, underwent extensive modernization between 2023 and 2025. The aim was to preserve the delicate steel and glass construction with its characteristic ribbon windows while complying with the contemporary standards for comfort and energy efficiency. The former single-pane glazing from the 1950s was therefore replaced with state-of-the-art FINEO vacuum glazing. A total of 1,270 glass elements measuring 1,100 by 750 millimeters were replaced across a façade area spanning some 850 square meters.

Upon its opening in 1936 Bromma ranked among the most modern facilities in Europe and was the first airport to have a fully concreted runway. Hedqvist applied the classic modernist maxim of “form follows function” to the architecture, organizing the workflows, functional zones and infrastructure of the original terminal in such a way that the principles of Scandinavian functionalism are immediately recognizable: clear volumes, a horizontal structure, large glazing sections and a deliberate absence of ornamentation. Bromma remained Sweden’s gateway to the world until the completion of Stockholm Arlanda Airport in 1962. In the 1950s the Stationsbyggnaden was extended and converted into a departure hall. From the first-floor restaurant above the passenger concourse, large windows offered a view of the runway.

 

 

After many decades of intensive use, the steel and glass structure was in urgent need of renovation. Moisture ingress, corrosion of the steel profiles and damage to the glass were characteristic of its deteriorated condition. This was caused among other things by wooden spacer blocks under the interior windows that encouraged water accumulation, and the original linseed oil-based putty, which had become porous, brittle and permeable to moisture. “Since the building is a listed monument, structural changes to the steel profiles were out of the question. All work had to strictly follow the prescribed reference photographs and as-built drawings,” says Thomas Sjödin, project manager at Ryds Glas Stockholm, the company responsible for the window restoration.

The single-pane glazing also dated back to the 1950s and no longer met modern requirements in terms of its energy efficiency, comfort and operational safety. Selecting the new glazing was therefore a highly complex task both in terms of preserving the listed building and from a technical perspective. Triple glazing with high thermal insulation performance would have been around 35 to 40 millimeters thick and would have overloaded the historic profiles. The FINEO Heritage series, specially developed for listed-building projects, was therefore used to modernize the historic windows in terms of their energy efficiency.

“The slim FINEO units fitted perfectly into the delicate existing frames. They also satisfied the conservation requirements because they precisely reproduce the optical qualities and texture of the historic glass,” Sjödin continues. The slightly irregular surface texture and characteristic reflection match exactly the appearance of the panels from the 1950s. This was achieved by laminating a 4-millimetre restoration glass from SCHOTT onto a 9.5-millimetre “FINEO 10”, resulting in a total thickness of only 13.5 millimeters for the new elements. The insulating units comprise two panes of extra-clear Clearvision glass from AGC, which is characterized by its particularly high levels of light transmission.

 

 

In addition to their optical authenticity, the energy performance was also a decisive factor. “Even with a minimum thickness of just 6.7 millimeters FINEO achieves U-values of 0.7 W/m²K, which would otherwise only be possible with triple glazing, “ says Ivar Nilsson, International Building Project Manager for AGC/FINEO, Nordic/Baltic Area, “opening up new possibilities for improvement of the energy performance of sensitive historic buildings.”

He explains the principle: “The functional heart of FINEO vacuum glazing is a vacuum cavity of 0.1 millimeter between two glass panes. Unlike conventional vacuum glass, there is no evacuation opening; instead the glass edge is hermetically fused. That guarantees permanent tightness without any need for maintenance, improved transparency and preserves the delicate historic character of the façade.”

For the Bromma renovation the vacuum glazing also delivered further properties relevant to the large-format ribbon windows of the departure hall: owing to the greater glass thicknesses available, the structural behavior was assured even for larger pane sizes without having to modify the existing steel profiles. At the same time, solar, UV and acoustic protection requirements could be integrated without compromising the historic appearance of the façade.

“FINEO Heritage was developed in close collaboration with leading suppliers of restoration glass manufactured using the traditional Fourcault process. Using five glass types we can reproduce the typical glazing of the periods from 1880 to the present day,” explains Clément Lemoine, Product and Market Manager at FINEO by AGC.

 

 

The renovation of the steel and glass façade commenced with the complete removal of rust from the existing profiles. They were then re-coated using a specialized corrosion-protective paint. Overall, the Ryds Glas team removed more than 3,500 rusted screws, which were replaced by new stainless-steel fasteners. A crane could not be used because the façade lies directly adjacent to the runway. All the panes therefore had to be lifted into the structure by winch or by hand.

“The decision in favor of vacuum glazing was also convincing from a sustainability perspective,” adds Lemoine. Vacuum glazing contains no noble gases and, by virtue of its very slim design, uses significantly less material than conventional double or triple glazing. AGC is also the first manufacturer to have obtained both CE marking and the general construction approval from the DIBt for FINEO. FINEO is also the first and the only VIG product with a third-party verified EPD, achieving an outstanding low value of 18,9 kg C02 equivalent per square meter, in its Low-Carbon version. This standardized and verified assessment gives a crucial advantage for projects and regions with high sustainability requirements. Long-term tests also demonstrate thermal and acoustic performance for more than sixty years. “Examples such as the renovation in Stockholm show that historic buildings can be significantly improved in terms of their energy efficiency using this technology without losing their character,” concludes Lemoine.