Steel window frames: slim and strong

The Zuid-Nederlandse Ramenfabriek (ZNR) is a strong advocate of steel as a material for window frames. The Rucphen-based company specializes in windows, doors and glass constructions made of steel. Here aesthetics are just as important as the added value through insulation, fire resistance and burglar resistance.

The South Netherlands Window Factory makes windows and doors from steel. Commercial director Jörn Jochems. "Steel can be recycled for 87% and reused for 12%. Therefore it fits perfectly within the concept of circular construction. It has a technical lifespan of 100 years and retains the same properties during that time, unlike aluminum. Steel is also three times as strong and much slimmer to execute." 

Advantages in renovation

According to Jochems, this makes steel window frames ideally suited for the renovation of old buildings. "Van Nelle Factory, for example, has chair profiles; we can ensure that this classic appearance is preserved while meeting today's needs. With aluminum this is not possible." For the monumental city hall in Leiden, ZNR supplied rear windows with the same sleek profiles as the original. They are mounted so that it is possible to wash between the windows. "Insulation was important here, as was extra fire resistance and burglary resistance," says ZNR. 

As early as the design phase, ZNR can assist architects with product knowledge and a pragmatic approach. "Our customer and solution orientation ensures that we can also provide contractors with optimum support. Unburdening from the design phase to assembly, in other words." In addition to standard products, customized solutions are also possible. 

Steel window frames also have good fire-resistant properties, Jochems explains. "Steel window frames meet higher fire resistance requirements and yet remain very slim. Architects are also looking for this, because large window sections are popular and large distances can be bridged with steel."

Burglar resistance is also an important issue for ZNR's customers. For example, the company recently supplied burglar-proof doors for the temporary housing of the House of Representatives. "We test these doors ourselves. By using steel, it is possible to achieve a high class." For a prison in Sittard, burglar resistance was of course important. For this project, ZNR provided SKG-IKOB-certified burglar-resistant windows, from the window, to the glass and bars. 

Also tested are ZNR's wall doors. These fall flush with the wall and can close automatically in the event of a fire to slow it down significantly. The Rucphen-based company is the only one that can provide such a solution.