Two main arguments are for the use of 3D printing, I would say.
This is the customization at no extra cost. 
But also then that we can create complex geometries that are not possible before.
My name is Benjamin Dillenburger, I’m professor for Digital Building Technologies
at ETH Zurich.  
So, I’m an architect and
I’m researching how one can use the computer to design
new kinds of architecture, unimaginable architecture
and then also finding the right, appropriate tools or strategies
how to fabricate those with robots.
Our project uses 3D printing in combination with concrete works.
But we are not directly 3D printing the concrete, we are
printing the formwork.
This means that we basically can take the advantage of 3D printing,
complex geometry is not an issue anymore,
bespoke geometry is not an issue anymore, 
but we can combine it with the traditionally very
strong structural capacities of concrete.
The idea is that we design a slab structure
which does not require so much material. 
That’s very relevant because usually in buildings slabs are
the part of the structure which take most of the material,
compared to the columns, or so.
Sometimes over 80% of the entire structure are slabs.
So if you want, and we have to, save materials in these structures,
we need to start to differentiate and optimize the forms.
And we are trying to tackle this challenge by using 3D printing to
make it cheaper and possible at all to save material and only use
concrete where needed.
The productivity in the building industry has to change.
We are facing
challenges in future, I think, some reports say in the next 50 years, 
we will build more houses than we’ve built so far – as mankind.
And if we want to do this in a sustainable way, we need to find 
new ways of building.
This makes total sense to scale up to, for example, high-rise buildings,
because every optimized slab would add on in terms of efficiency.
We could maybe save the floor height and then maybe gain a couple of
floors for an entire high-rise building.
So there’s a huge potential and we believe that technologies like robotic
fabrication and 3D printing is very well-suited to enter this market
because in architecture, in the best case we anyway don’t want to 
standardize each building.
Architecture is much stronger and much better performing if you have
really customized solutions for the specific context.
And here then digital fabrication comes into play.
