What Does "Beautiful Architecture" Really Mean?
Canons
Every nation's culture dictates its own vision of architecture. From the earliest times, we have endowed buildings with sacred meaning. European architecture has its origins in Byzantium and Rome. To be beautiful meant to be made according to tradition, to the established order. Over the centuries, almost nothing changed. A single good book on architecture was enough to last 200 or 300 years. Questions about beauty came down to a question of conformity to the canons.
Few classicist architects strove for originality. Among them reigned an almost complete consensus about how every element of the facade and the building's interior layout should be arranged.
The Huntington Library, Berkeley.
The design of the common people's small dwellings came down to a handful of factors. Building materials and climate limited the ways in which walls, roofs, and facade decoration could be built. Bringing materials in from other regions was an extremely expensive undertaking. People had to use whatever was on hand.
On top of that, there were no picture books back then. People rarely traveled to see unfamiliar architecture for themselves. That is why many early Northern European books depict the structure in which Christ was born as a Scandinavian chalet.
Broken Landmarks
Then came books, roads, and scholarly travelers. After many expeditions, written architectural guides to faraway countries were gathered under one roof. It is well known that foreign architects were invited to Russia more than once. There were proposals to build in the Italian, French, or even Indian manner. Experiments and eclecticism blurred the very concept of a norm or canon. What was now considered beautiful and correct? After all, anything could be built.
The Engineers' Point of View
And then a new profession arrived on the scene: the engineers. The Industrial Revolution had come. Cities needed hangars, train stations, bridges, and factories. All of this became possible thanks to steel and concrete. The new aesthetic proclaimed that what is functional is beautiful. A bridge is elegant when we are struck by the lightness with which a thin, seemingly weightless structure can carry an enormous number of cars.
Before long, however, the manifesto of functionality began to reveal its excessive rigidity, hardening into a ban on any discussion of architectural beauty. The engineers had taken over. A building was deemed a success if every element served a function, and a failure if it bore any decorative pattern.
More to the point, the modernist architects remained every bit as romantic as their predecessors. The architecture they created also tried to do more than shelter people from sun or rain; it sought to evoke a particular mood. Their buildings were stage sets for the ideal life of the future they were promoting.
The aesthetic image of modernism mattered so much to these architects that more than once they betrayed even their own ideals of practicality. The Villa Savoye was an expensive architectural whim, built by hand. Its walls and roof were meant to create a special sense of superiority and otherness, much like the jewel-encrusted aisles of a Catholic church during the Counter-Reformation. By modernist standards, the flat roof was just as much a sham as the buildings of the Classicists.
Correspondence between the lady of a modernist villa
and her architect
Madame Savoye 1936

Le Corbusier
Madame Savoye 1937
If modernist architects cared so much about beauty, why did they always talk about a scientific approach? Out of fear of falling under the same suspicion of pretentiousness as their classical colleagues. Rejecting the universal principle of beauty created the conditions for a universal critique of styles. "Science" helped win over the doubters.
So How Do You Define a Beautiful Facade?
And yet we can decide the question of beauty for ourselves. To do so, we have to remember that architecture is always speaking to us. It speaks to each person individually: of longing for the past or aspiration toward the future, of hospitality or threat, of openness or arrogance, of democracy or aristocracy.
Every object makes a certain impression on us. When we call a building beautiful, it is likely that we like the way of life it offers.
The resulting sense of beauty tells us that we have encountered a material expression of our ideas about the good life. This is why judgments about the beauty of architecture turn into broader arguments about people, ideas, and political agendas.
For each of us, judging the beauty of architecture is a decision about what is good and what is bad. Buildings that speak to us help us think about our values, not merely about how we would like the things around us to look.