Imagine you are a city or any other public administration with urban planning powers. How to foster the use of a given architectural shape without paying for it? Reducing the cost for those producing it. In a given moment, the city of Madrid decides that the floor area of a bow window is accounted for just about 50% of its size in the overall floor area permitted by the municipal plan on each lot. So it is a more profitable space than other square meters in the building. This explains why you so often this shape in the Madrid architecture of the last two decades.
Is this a better architectural solution? A more elegant one? You cannot say, as this depends on each project. Conversely, some cities as Barcelona are much less welcoming towards these bow windows, and this has been a tradition for more than a century. It is a matter of local sensibility… Barcelona’s position derives from the overcrowding in the old city before the Cerda extension in mid XIXth century, when cantilevering rooms sometimes covered the street. I could not trace back the reason for Madrid’s permissiveness.
That’s interesting. I think there is a similar rule regarding the setback from the street in a lot of towns in the US that applies to 2nd floors. The setback is/was often measured at grade level. So, if the 2nd floor is cantilevered out an additional 12-16″ it doesn’t affect the measurement. Now, that has become an architectural style of its own. However, I’m sure they are taxed for the sq footage 🙂
Well, it seems a case of universal unanimity: urban planners are ready for a discount, but the tax man is ever more zealous (something similar happens this side of the sea…))