Ireland's Letterfrack installation at the Venice biennale is a masterclass in design and metaphor, says Hugh Pearman It is a building, an installation, a memory of hard times in Connemara and an object lesson in how perceptions can be turned around. The Irish entry at the Venice Architecture Biennale, entitled the Transformation of an Institution, carries a far more powerful charge than most of the offerings on display from around the world. On paper it does not look much - a single-project national exhibition in a year when most participating countries crammed as many architects and projects as possible into their showpiece pavilions as the biennale celebrates its 20th birthday. After all, it has become the most prestigious public exhibition of contemporary architecture in the world. But Ireland, which has never had a permanent home at this Venetian arts enclave, has turned this apparent deficiency to advantage. Its single design is ripe with meaning, adroitly displayed as an independent work of architecture in its own right. It also occupies a prominent position befitting its status - difficult to achieve in this jostling kasbah . . . Generally, with a piece of work such as this, you find things that irk you. Architects often do not make good exhibition designers and vice versa. Here, there is nothing I would want to add or take away or even amend. Real, emotionally charged and informative architecture in an architecture exhibition? You'd be surprised how uncommon that is.

