Perhaps more than anything else, the facade determines the visual character of a building, while also making a significant contribution to the energy performance and comfort of occupiers. Here, we examine some of the key design trends for modern buildings, and the technical advances enabling architects to achieve them.
One of the biggest trends we are seeing is clients demanding, and architects delivering, building designs that are unique, innovative, sustainable, reflective of its use of history, and even structures that are instantly iconic. Due to the continual advances in design, manufacture and construction it is now possible to make these concepts a reality.
For example, the internationally acclaimed extension to the German National Library in Leipzig was designed to give the appearance of a book laying on its side. The roof and curving facade form the 'cover' and 'spine' and are constructed from triangular aluminium composite cladding panels using our WICTEC 50EL unitised curtain walling system. In the UK, our WICTEC and WICLINE systems were used to create the facade of the RIBA Award winning Gasholders development in London. The fully cylindrical buildings were built inside the Grade II listed steel framework of town gas storage structures dating from the 1880s.
Another key trend is the integration of vegetation into the design of buildings. This is achieved in several different ways such as living walls, where plants are grown in vertically installed panels with their own watering system. We are also seeing more instances of specially designed frameworks being used to support the plants as they grow up the facade. In contrast to living walls, these are rooted in soil around the building or grown from a plant located on a lower rooftop terrace. This offers a simpler and much lower maintenance solution and allows living elements to be integrated into a wider range of buildings.
Growing plants onto the facades in this way not only helps introduce much needed vegetation into urban areas but also has benefits for the building. For example, it has been shown to reduce solar heating of the building interiors, minimising air conditioning costs during the warmer months.
Designing for Energy Efficiency
The ongoing emphasis on the environmental impact of buildings has only increased since the UK Government's pledge to pursue a 'net zero' carbon target by 2050. Increasingly, designers are taking a 'fabric first' approach to this challenge.
This means that every element of the facade must provide effective thermal insulation to prevent heat loss. A big part of this is minimising the air permeability and creating an increased thermal break between the interior and exterior surface using insulation elements built into the facade systems. Building specifications now increasingly demand that building envelope elements meet the strictest standards and have undergone rigorous testing and certification. This is why we continue to invest in our state-of-the-art Test Centre near Bellenberg in Germany where new WICONA products and project specific solutions are tested and evaluated.
The push for improved energy efficiency has also been one of the drivers behind the growth of 'kinetic facades'. As the name implies, these are facades that include elements that are designed to move. In some cases, this has been used purely for aesthetic reasons to create an eye-catching building exterior. However, the concept is increasingly being employed to help manage the environmental conditions within a building and therefore improving the energy efficiency. Kinetic elements may include solar shading that moves throughout the day to prevent overheating or automatically opening sections that can provide the correct level of ventilation throughout the day and night.
At WICONA, we have developed the TEmotion intelligent facade system, that integrates the facade with the Building Management System to optimise the efficiency of the heating, lighting and ventilation systems.
Looking at Lifecycle Impacts and Embodied Carbon
The materials used in facades are also changing. With the industry becoming more aware of the environmental impact of traditional materials such as brick, the use of lower carbon footprint options is growing.
In particular, aluminium now has the fastest growing demand among all metals for construction and is seen as having a crucial role in reducing the total environmental impact of the building - known as embodied carbon. This includes everything from extraction of raw materials and manufacturing of components, through to the occupation of the building and finally, its demolition and disposal.
Unlike other materials, it is endlessly recyclable with no degradation in quality and is easy to separate from other waste. A further advantage of recycled aluminium is that melting it down for reuse requires only around 5% of the energy needed for primary aluminium production. This means that products, and therefore, buildings that use recycled aluminium have a much smaller carbon footprint.
As an example, we are adding new products to our range that are manufactured using Hydro CIRCAL 75R, a high-quality aluminium that contains a minimum of 75% recycled post-consumer aluminium. At just 2.3kg CO2 per kilo of aluminium, it has one of the smallest carbon footprints in the world - 84% less than the global average for primary extraction. The systems already available that feature this 'infinite aluminium' include WICTEC 50, WICSTYLE 75 and WICLINE 75 MAX, the innovative window series that has been recognised by the Red Dot and If Design Awards.
The facade design is an element of the building that is always evolving, driven by new technology and shaped by a range of local, global, environmental and societal factors.