Reasons given were that the irregularly shaped St Mary's Axe Tower - initially dubbed the 'Erotic Gherkin' - is ill-suited to the practical requirements of the financial companies to whom part of it was offered as rental office space.

The tower was sold last week by owner Swiss Re, but it will continue to occupy part of the building as the main tenant. Speculation on the reason for the sale is that the company had difficulty renting out the excess floors not required for staff. Forty per cent of a 41-storey tower is a considerable amount of wasted space, and critics of modern architecture will cite this as an example of design taking precedence over the function intended.

A number of architects in Ireland suggest that efficient use of space must be balanced with aesthetics and civic pride, especially in a landmark building.

"When you look at that figure of 40% loss of use, you could point to Dublin's historic Georgian buildings that have been converted to use as office space, " says Joe Kennedy of Smith Kennedy Architects. "These buildings are not really suitable as office space, aside from the conservation issues involved in any refurbishment. The space of the typical Georgian townhouse is usually 3,000sq ft.

But in terms of efficiency you are losing about 20% of usable space because, apart from the high ceilings that comprise part of the space, you really couldn't have more than four people working in an average-sized Georgian room.

"In any building, you have about 15 to 18% of space given over to lifts shafts, and other services. Add that to the 20% mentioned, and you practically come up with that figure of 40% unused space as reported in the Gherkin."

It seems that many companies are prepared to sacrifice a degree of function and want status buildings, whether historic or avantgarde modern, for the kudos they bring. Setting aside the matter of efficient use of space, innovative building design in itself can have benefits for the wider community in a major city. Bilbao, for example, could have been a dull place with its cityscape of efficiently used buildings, says Joe Kennedy.

"Then along came Frank Gehry with the Guggenheim museum which gave the place a unique identity and the look of everything around it. At another extreme, the typical Soviet building was based on the square, as it was considered the best use of space.

That may have been so, but it resulted in very bland and uninspiring architecture."

The 120 metre Spire has radically changed the Dublin skyline and although created as a landmark of modern art, there are some who feel that the chance to also use it as a lofty viewing point was a missed opportunity. John Graby, director of the Royal Institute of the Architects of Ireland, is having none of that.

The 'wow' factor - which Dublin is lacking elsewhere - is what's important here.

"The whole point of the Spire was to create a landmark. I don't necessarily feel that the facility to climb it as a sight-seeing vantage point would be that big a draw these days. I can remember going up the original Nelson's Column and that was a novelty back then. We have moved on since then. Now we have the Smithfield tower, and the Gravity Bar at the Guinness Hop Store. Another tall viewing point is not that unique.

The Spire inspires in what is a public street. And in a city, we need a civic wonder. Euro4.8m is not a huge amount to pay for something that gives back civic pride."

As one commentator said of the Gherkin: "As a piece of real estate, it's not very clever.

But it put Swiss Re on the map and it's been very good for London."

FOSTER'S GHERKIN THE prize-winning St Mary's Axe Tower - referred to by Londoners as the 'Gherkin' - was designed by renowned architect Norman Foster using his trademark glass and steel construction. It opened in 2003.

Other landmark projects of Foster's include the Reichstag in Berlin, the Milau viaduct bridge in France (the highest bridge in the world), and Wembley stadium.

Owners of the Gherkin, re-insurers Swiss Re, had dif"culty renting out 40% of unused space in the building due to the circular design incorporating irregular shaped "oors and curving walls. Any criticism of the design of the tower is unlikely to cause any wobble with regards future commissions, however, even though the architect's work has never been far from controversy .

The Millennium Bridge, between Tate Modern and St Paul's in London, had to close as soon as it opened in 2000 because it wobbled too much (the problem was recti"ed by the architect after a closure of 18 months).