It is no coincidence that the projection, i.e. the depth of a floor-standing washbasin, has levelled off at around 48 centimetres over time. Not only the ceramic appliance, but also the matching furniture units and even the taps are normally precut to this dimension.
Just like with many other things that we use on daily basis, these elements have been standardised as a result of industrialisation. In the past, washbasins were considerably larger, but there has been a trend towards minimisation. Of course, apartments and their bathrooms and guest WCs have also become smaller over time. But this minimalist trend has not stopped at 48 centimetres: Nowadays, there are a large number of mini washbasins with a projection of 37 or even 25 centimetres, which are specifically designed for small guest WCs.