Building shell
integrative planning

Facades that "think" –
why good engineering planning is so important

Suppose you are the customer of an office building which you want to market with a good return – what is important to you?

You will require an attractive appearance in order to offer your customers optimum workplace quality. Needless to say that the building is to operate with high energy efficiency whilst complying with all statutory requirements and generating the lowest operating costs possible. But: who can tell you how to achieve your aims within a short construction time and at a reasonable cost? The architect recommends a double facade, arguing in favour of "natural ventilation". However, if the windows remain closed at night, the positive effect is foregone. Should the opening and closing of the windows then be controlled centrally, or are decentralised air handling units the answer? What about the planned fairfaced concrete? Or should one use concrete core temperature core control and central ventilation instead? What are the pros and cons of the different solutions, and what does this mean for the costs? And what about the cleaning concept?

"Intelligent facades" are en vogue. Forward-looking customers expect a facade which does more than just look nice. In short, what it is needed are facades that "think". This claim has its price: Up to one third of the capital invested in new construction projects is today be spent on the facade alone. The facade has hence experienced an enormous increase in value within a construction project. Not least because of growing energy requirements, the facade is understood, together with the roof, as the building's breathing shell. This building shell has important functions. It controls all the exchange processes between the inside and outside. The selfregulating building shell performs part or all of the heating, cooling and ventilation functions. Integrated control equipment does not activate the technical building systems until needed. The same holds true for lighting where the use of daylight is a top priority.

Innovative materials and a well-conceived sun protection design ensure glare-free light, reducing the use of artificial light sources to a minimum. Although modern facades do not render technical building systems superfluous, technical building systems and facade are combined to form a system which is connected by the appropriate control systems. This increases the feeling of comfort in the building and at the same time saves significant amounts of energy. Finally, a facade fitted with photovoltaic modules also covers part of the building's energy demand.

In this way, the "intelligent facade" is also a visually perceived element of sustainable building. What two decades ago still was a clumsy and unattractive "eco"-building and deterred architects from a design perspective, is today an aesthetically interesting and multi-faceted solution. After the engineers, architects then also discovered the attraction of the technical sophistication of thinking facades and embarked on sustainable building. In the design of new buildings, the "sustainability" aspect is today particularly popular – and the facade returns to its initial purpose of representation: Bold, transparent and sustainable architecture can today be implemented without conflict.
However, the technical and financial input also means risks. The intelligent facade depends on the seamless interaction of all factors and components, so that the intended effect is achieved not just in the simulation model, but also in real life. This can fail and thereby cause costly extension of construction time, revision of plans and designs or even subsequent rehabilitation work on the completed building.

The only way to avoid such unpleasant surprises is a design and planning approach which brings all the engineers and specialist planners together from the very beginning. The traditional approach is no longer sufficient where the individual planning and design disciplines, i.e. architecture, bearing structure, technical building systems and building physics, were handled by the individual specialists without interaction. From the very beginning, i.e. from the point of idea development on, the architect needs the support of the engineers assisting him in the implementation of his design concept. There is no other way to rule out serious planning and design mistakes which eventually cost the customer a lot of money.