A building may appeal for its formal perfection, its harmony of proportion and the grammatical discipline with which it matches part to part. But it may appeal despite lacking those things, by offering enticing glimpses of the life within, intriguing apertures, invitations to enter, to explore, to imagine.

The much-loved villages of Provence and the Italian Riviera provide few examples of formal perfection. But they abound in doorways, passages and cul-de-sacs; in secret stairs and alleyways. Their walls are punctuated with votive shrines and niches; their windows are encased by architraves and moldings, often squeezed into corners to reflect the winding corridors of the life within. Basements sink away into darkened cubby-holes, and here and there, between the houses, there are sheds and troughs that serve the needs of the invisible gnomes who haunt the place.

The art of producing these nooks and crannies, and fitting the buildings around them so that they become part of the fabric of the street, is integral to the success of our traditional architecture, and was evident right down to the early New York skyscrapers, where such details occur in the most surprising places, on the façade, the roof, the recesses, the service doors, and in the dim back yards.

Why are nooks and crannies no longer produced? One reason is that their value is not understood, and in any case no longer taught as part of place-making. But their absence is also a result of the prevailing styles—which are not so much styles as the avoidance of style, and which leave no room for the accidental, the decorative, and the fantastic. Gothic architecture, Sir John Summerson once argued, was a kind of generalization of the ‘aedicule’—the little building of pitched roof and upright walls, which was accumulated cell upon cell to form the great organism of the medieval cathedral. The nook and the cranny were the essence of the style, the units of meaning which were picked up and spread by the architect across the whole façade.

Classical architecture used moldings and shadows to create mystery and intimacy within the geometrically organized forms. And vernacular architecture has borrowed from both the Gothic and the Classical traditions, aiming for a free and extendable vocabulary, which can be incorporated into the façade and the street regardless of the life that punches holes and builds shelters where no architect has planned that they should be. But that free response to human need fits ill with our modern ways of building. Walls are no longer shared, buildings no longer evolve or adapt, new apertures are no longer made in old facades, nothing leans on anything else but all stands clear and detached, circumscribed by a function that cannot be easily changed.

Nooks and crannies occur in an ancient town like the endearing wrinkles on an aged face. But how can they be incorporated into buildings constructed on the principles of curtain-wall architecture? Unbroken sheets of glass, prefabricated panels, poured concrete, steel girders—these are the basic units of construction, and all resist the kind of random puncturing and cobbling that subordinated the work of the architect to the changing needs of the community. The frozen and unbroken facades of the curtain-wall idiom make no room for these details; our modern facades encase the inner life of a building, but do not evolve or adapt in response to it.

Sir Roger Scruton is The American Conservative’s New Urbanism fellow.