It's Just A Façade..?
The word ‘façade’ has a few different meanings. (That’s what happens when we steal words and phrases from our Latin friends!) It literally means “face”, which over time has been extended to mean ‘of limited depth’, or ‘shallow’. This negative context can then be absorbed into the psyche to mean that it is of little substance and therefore not important.
It’s just a façade? Its just a front, isn’t it? Well, of course that is true - that is all it is, and there is no getting away from it. It doesn’t support the building and is considered structurally - at best – to be of secondary importance.
When engineers design buildings, the façade is often considered as an “additional weight” that must be carried by the frame, or a means from which wind is applied to the main structure. An inconvenient part of the process if you like.
However, let’s consider the façade as a “skin”. (I know this might be pushing the emotive analogy a bit too far, but bear with it…)
If we forget about the gooey stuff and think about what a skin does? It is a fairly important organ. It regulates our temperature. It protects us from the sun. It stops water coming in, but allows water to leak out, even though it has all sorts of other things sticking out from it. It can absorb some stuff, but not others. It stretches when we move. It stretches a bit more when we get fat. It gets a bit thinner as we get old, but it lasts a long time and is pretty (certainly, we are prettier with it than without it!)
Do you see where we are going here??
Building façades (or skins) are amazing things. They may be shallow in depth, but they must also provide all these functions for our buildings. They create colour and texture and shape and give buildings their character. Façades dictate how much light flows into a building, and has a major say in temperature regulation and all the M&E design that follows, to ensure that the buildings are comfortable. A well-designed façade can significantly reduce energy requirements and contribute towards a sustainable future.
Building structures are amazing, but they are tricky little so and so’s. They sag and they sway, and they shrink and tilt. Sometimes they decide to settle a bit, and they often take years to do it. And with a change in wind direction or usage they move again in a different way. They really are alive in that sense. Moreover, the façade that is erected right at the start of the building’s life needs to account for all the things that may happen over the subsequent 30 years or so. That is a big ask…
Whilst façades may not immediately appear to be of “structural significance”, it is well understood that resistance to wind loading is a critical stability requirement for most buildings – and yet without a façade there is very little load on a building.
Bomb or impact resistant façades most certainly are of structural importance. They save lives. The way these façades move, absorb energy and interface with the supporting structure are so important to how they perform such a critical function.
We love structures, but we do have a particular soft spot for façades. We will be posting a few articles over the coming months on various aspects of façade design. As structural engineers, these posts will undoubtedly have a structural bias, but we will look at other aspects in less detail to give them a bit of colour and context.
However, they won’t all be “this is one we did earlier” Blue Peter style, where we bask in the ambiguous glory of a finished building. We will try to cover some of the mucky stuff, and lots of the stuff people pretend to know but don’t. We will also discuss the bits we don’t know (yet) either!
We hope you enjoy them.