Due to its proximity to the city of Frankfurt, numerous large corporations such as Arcor, DB Real Estate or Ernst & Young have settled in Eschborn in previous years. Most recently, the high-rise office building 'Matchbox' has been completed on the last available plot on Frankfurter Straße. The name is derived from the deliberately calm, rectangular ‘box’ shape of the building in terms of urban planning and the many possible uses of the property. The generously glazed new building, which was completed within a construction period of just 15 months, integrates flexible office spaces across ten pillar-free floors that can be split into open-plan offices or individual areas as required. On the ground floor, there is also a showroom for medical imaging technology.

The newbuild is characterised architecturally by the harmoniously subdivided glass façade, which makes an important contribution in optimising the building's sustainability through the integrated photovoltaic modules. The starting point for implementing BIPV from Schüco was the demand from the client. "The objective was to create a sustainable and future-orientated building with high energy efficiency that is operated entirely without natural gas or other fossil fuels," says Salar Ebadollahi, CEO of Lang & Cie. Real Estate AG. "During planning, we had run through various options with everyone involved such as biogas, pellet heating or geothermal power and we decided then on air-to-water heat pumps combined with a roof-integrated photovoltaic system." For an additional reduction in electricity demand, it was ultimately decided to also use the façade for generating power as well as the roof surface. 

The façade was completed as an individually adapted special design of the Schüco AWS 75 BS.HI+ highly thermally insulated aluminium window system combined with the building integrated photovoltaic system from Schüco. The Cradle-to-Cradle-certified system was consciously put into practice to achieve a unified overall impression and to obtain a maximum total return in spite of reduced efficiency on the less light-exposed northern side. The integrated PV modules supply an output of around 180,000 kWh per year and, in combination with the PV system on the roof, cover more than half of the total energy requirement for electricity each year. The PV units generate a direct current via the inverter which is fed directly into the home network. Heat and refrigeration are generated purely electrically via two heat pumps and two cooling units. Surplus power is dispensed to the public network during summer peaks. "The transformed façade solution ensures a significant reduction in operating costs. It also enables considerably easier leasing and a higher return," says Salar Ebadollahi, summarising the added value.

Despite its high energy efficiency, the façade is not recognisable as a solar façade, but instead follows the design requirements of the architects. "Based on our concept, the implemented solution is ultimately just a representation of a load-bearing structure in a well-proportioned way," architect Nicolas Schrabeck explains. "BIPV does not give the façade anything formalistic or decorative, but simply reflects the usage and statics of the building within the sense of ‘form follows function’."

The architects also came forward to positively praise the support from Schüco. "The company acted not only as the system supplier, but also stood by us as a partner for the project-specific implementation of the façade," recaps Nicolas Schrabeck. "We have utilised the option to adjust the shade of the PV units individually to design the façade in a monochromatic, almost black shade. The bronze-coloured edging of the windows forms a subtle contrast to this." As a result, the glass shell, which is otherwise characterised by windows and PV elements, has gained a pleasant and high-quality rhythm. Distracting reflections, e.g. the reflection of sunlight, are prevented. This clearly demonstrates that a design-orientated façade and the use of BIPV are by no means mutually exclusive.

The BIPV modules promise long-lasting operation and thereby swift amortisation. And should a PV module need to be exchanged, this can be done at a low cost. This is because the building was not only designed with sustainable operation in mind, but also in view of deconstruction and recycling: the Schüco AWS aluminium window systems selected for Matchbox are Cradle-to-Cradle-certified. And equally the integrated BIPV modules can also be recycled via glass recycling. Consequently, complete recycling within the material cycle is possible. "Disposal does not involve hazardous waste,’ explains architect Nicolas Schrabeck.

With this project, the façade specialist Schüco is demonstrating its claim to reduce the carbon footprint of a building holistically over its entire lifecycle with the help of Schüco Carbon Control – from design to construction and building operation through to recycling. The backdrop to this concept is the European Green Deal, which envisages Europe to be climate neutral by 2050 and therefore requires significant steps in terms of building operation. "Ultimately around 42 percent of the annual global CO₂ emissions are being caused by the construction industry alone and around 27 percent of this quantity is attributed to the building operation," as Schüco project engineer Marco Schech explains. In view of this and in order to achieve a clear reduction in these emissions, as a pioneer within the industry, we offer the modular Carbon Control initiative, which makes it possible to control the decarbonisation of the façade throughout the lifecycle of a building on a property-specific basis." The outcome is a building envelope that is designed to be holistically systematic and saves CO₂ throughout the entire lifecycle.