Reading Peter Zumthor’s own vibrantly eloquent descriptions of his new creation, ‘Hortus Conclusus’ - this year’s Summer Pavilion at the Serpentine Gallery - one is transported to a world of tranquillity and calm. He aspires to create a garden cut off from the hustle and bustle of London; an intimate space in which to reflect. Sadly, the ideals of liberty from the lethargy of London life are far from represented in the work, and Zumthor’s vision, to my eye, fails to reach fruition.

Aesthetically speaking, the impact of the installation is less than profound. The simple black exterior evokes no sense of intrigue, no yearning to discover what lies within. Moreover, it is a blot on the landscape, stark and unadorned. It does not invite you in, it is not welcoming, and, in fact, it verges on blandness. What’s more, the interlude between the outer world and the inner garden of Zumthor’s creation, formed by a darkened alleyway, is far too brief to create any real contrast – it lacks the crucial build up of suspense to give the discovery of the garden any real emotional impact.

The inner realm itself, designed by Piet Oudolf, is equally uninspiring. With the promise of tranquillity, one might expect a wild garden, free of constraints and constrictions, beautifully unkempt and uncontainable. Contrastingly, there is the alternative expectation of a perfectly landscaped, immaculate space: bright green grass, trimmed and preened; the sound of running water; a dominating yet unimposing fountain at the centre – a garden with an ethereal aspect. Oudolf’s design fits neither ideal. The plants grow among each other in a flurry of colours and textures, yes, but the synthesis appears chaotic and frenzied. The colours verge on garishness; there is no harmony in their synthesis.  In one sense, then, this is a wild garden:  unimpeded, unrestrained and free. Yet the plants are held within a strict rectangular shape: contained, constrained, inhibited. It unintentionally becomes a metaphor not for freedom from a fast-paced world, but entrapment.

The open-roofed element is almost a saving grace, suggestive of infinite possibilities and freedoms, but again, it is framed, enclosed, and its impact depleted. Had the walls been higher, it could have been a tunnel to the heavens, making a profound impression, but as it is it has no real strength as a concept.

The installation is set in the heart of Kensington gardens - beloved for its vast expanses of green amidst a grey city, and itself a relief from the furore of the Capital. Thus, ‘Hortus Conlucus’, translated as ‘enclosed space’, becomes not an escape but literally an enclosure. It is too small, too structured, too mundane to encourage inspiration and interest. As a concept, it would be much more effective in the middle of bustling Oxford Street or Canary Wharf. There it could be a haven, a refuge of relaxation from the crowds. Out in the open air of Kensington Gardens, holing away in an encased area seems an unhappy prospect.

Zumthor’s creation follows ten previous innovations in the Summer Pavilion Series. Last year’s design, conceived by French architect Jean Nouvel, was a blazing red geometric phenomenon, contrasting dramatically with the green scope of its setting. In this case the stark quality of the piece was engaging. The colour represented perfectly our capital, imitating the telephone boxes, post boxes and London buses. Comparatively, Zumthor’s work has a standoffish quality; the intimidating black block conveys coldness and hostility. It is underwhelming, uninteresting and utterly tedious.

Peter Zumthor’s ‘Hortus Conclusus’, located beside the Serpentine Gallery, has free entry and is open till 16 October 2011.