A major discrepancy between the winning scheme for the U2 Tower at Britain Quay in Dublin's Docklands and the much taller structure intended to be built is revealed by a drawing obtained by The Irish Times.
This follows a hotly contested competition involving four development consortiums for the contract to build the tower, which would include an egg-shaped studio "pod" for the U2 rock group suspended above a public observation deck.
The drawing supplied by the Dublin Docklands Development Authority (DDDA) shows two versions of the west elevation of the tower designed by international architects Foster + Partners and chosen by the authority as its winning scheme last month.
On the left is the scheme which was adjudicated on in the competition. It complied with the requirements of the DDDA's brief and, in particular, the height limitations of the amended planning scheme for the Grand Canal Docks.
The planning scheme specified that the main element of the U2 Tower should not exceed 100m in height to its "shoulder", and any accommodation above this level was not to bring the overall height to more than 120m.
It said "architectural features having non-useable floorspace" above these maximum recommended height would be considered on a case- by-case basis. Foster's winning scheme availed of this allowance to clock in at 130m.
But the tower intended to be built (shown right) would rise to 180m - 50m higher than the scheme which was adjudicated on. This additional height would house its energy centre, including vertical wind turbines.
Looking at the two images, it is clear that the taller one is well resolved geometrically, in that it comes to a clear point. The lower version looks truncated by comparison, as if it was "lopped" to comply with the height limits.
The lower element of the scheme, resembling a butterfly wing, would provide a five-star hotel, with social housing tucked underneath it.
Between this and the tower containing luxury apartments, there is an arched opening towards the river Dodder.
At present, the DDDA's official position is that Foster's clients - a consortium of Ballymore Properties, developer Paddy McKillen and the members of U2 - are the "provisional preferred bidders" for the project, pending further negotiations.
The DDDA says it "may consider the energy centre in due course subject to technical and planning criteria" and insists that "this was not considered in assessing the competition as it is outside the guideline heights".
But if there is any question of building a tower that departs so significantly from the height limits specified in the Grand Canal Docks planning scheme, that scheme - adopted as recently as July 2006 - would need to be amended.
And if this was proposed, the disappointed underbidders - Mountbrook Homes, Treasury Holdings/Sisk and the Riverside Partnership - would have even more reason to feel aggrieved at the outcome than they are already.
Already, there has been talk of litigation to challenge the DDDA's decision to award the project to Ballymore, U2 and Mr McKillen, on the basis that the authority broke its own rules. But so far, none of the underbidders have initiated proceedings.