Sou Fujimoto’s Serpentine Pavilion, London

The grid is something almost preternaturally attractive to architects. The ultimate abstraction, it is a mechanism for overlaying the idea of a building on to the physical reality of a landscape or the exigencies of a city. Usually it fades away, receding into the earliest phases of the architect’s plan as the building rises. But in this year’s Serpentine Pavilion in Kensington Gardens, London, the grid is not only still visible, it has expanded from two to three dimensions – indeed, it has become the whole building. And it is absolutely beautiful.

If you can imagine trying to build a cloud out of sticks, this is it. It sounds completely counterintuitive, the fluffy from the geometric, but what Japanese architect Sou Fujimoto (at 41, the youngest designer of the annual series so far) has done is to construct a seductively complex structure from the simplest possible system – a series of white-painted steel sections and glass surfaces.

When seen in isolation the steel bars appear insignificant, slender, lightweight and barely there. But as you move around (and in and out of) the structure and see the bars’ increasing density in various directions, it starts to seem almost solid. Even the slightest shift in viewpoint proves enough for it to change, as new limits or openings shift into focus.

Horizontal glass surfaces allow parts of the structure to become steps and terraces so that you can position yourself on another level, your body becoming a part of the complexity. Further up still, a series of nearly invisible transparent discs creates a covering for the space below, which will form the auditorium for the gallery’s marathon arts events.

Fujimoto’s pavilion is a magical realisation of an architect’s first sketch, a fuzzy mess of horizontal and vertical hatching in which the edges just seem to fade out and crudely implied figures hover mysteriously at different levels. The impact is similar to that other great Japanese Serpentine success, the Sanaa pavilion of 2009, which similarly seemed almost to disappear into the sky while making an incredible architectural impression.

There is a precedent for the form of this pavilion in Fujimoto’s oeuvre. His “House NA” in Tokyo is one of the most strikingly conceptual houses of recent years. It is conceived as an inhabitable climbing frame with myriad mini-levels which act as tables, seats, plant stands, sleeping ledges and so on. It allows a multi-level existence, in which, rather than creating a space on the single floor of a large room, the dweller inhabits a customisable and complex landscape of levels. Fujimoto has compared this to how a child might choose a branch of a tree on which to sit or find a different way to climb it, each position giving a new perspective on the structure. It’s a wonderful image – though perhaps it better suits the Japanese tendency towards the neat inhabitation of micro-spaces than the messy sprawl of western lifestyles.

That idea of inhabiting an overwhelmingly abstract structure, a three-dimensional grid, was a trope of 1960s radical architecture. Yona Friedman, Superstudio and the situationist Constant Nieuwenhuys (in his designs for a “New Babylon”) all proposed variants where citizens would find their place within a megastructure in which bourgeois hierarchies and notions of private property had disappeared. It was an alternative idea of an anarchic city conceived as a framework limited only by the imagination. (It is ironic that the phrase “off-grid” has come to connote exactly the freedom sought by the designers of these utopian systems.)

The wonderful thing about a pavilion in a park is that the practical problems of creating such a structure in the real bourgeois metropolis of land value, economics and use class just melt away. The Serpentine Pavilion programme provides a platform for pure architectural ideas unfettered by concerns over function – which is precisely what makes it such a delight. Its impermanence makes it an event, creating an intensity that permanent architecture struggles to supply. Fujimoto has delivered a building that is ineffably light and seductively complex, perhaps the most exquisite this site has seen.

June 8-October 20,

Copyright The Financial Times Limited 2017. All rights reserved. You may share using our article tools. Please don't cut articles from and redistribute by email or post to the web.