Dublin Corporation must be commended for its planning decision on Spencer Dock. The fact that chief planning officer Mr Pat McDonnell's report runs to 163 pages is in itself an indication of the corporation's comprehensive assessment of what is by far the largest urban development ever planned in Ireland.

What emerged last Friday was something like Solomon's judgment. The tactics employed by the Spencer Dock developers, on the lines of "don't hit me now with the child in my arms", did not produce the result they were seeking. The child in question, the National Conference Centre, is now virtually an orphan.

The development consortium - Treasury Holdings, Mr Harry Crosbie, the Docklands entrepreneur, and CIE as freehold owners of the pivotal 51-acre site - had gambled on getting a more favourable decision from the corporation than they might have got from the Dublin Docklands Development Authority.

Relations between the developers and the authority had broken down last autumn in very acrimonious circumstances - partly because the authority itself wanted to get its hands on the site and also because it was simply not prepared to make a planning scheme which would have given them what they wanted.

Six million square feet of mainly high-rise buildings, ranging in height up to 95 metres on a two-storey podium across much of the site, was too large to swallow. There was - and is - widespread opposition from conservationists, local residents, Dublin architects, the docklands authority and other interests.

The developers were banking on the city manager, Mr John Fitzgerald, taking a more sympathetic view, but the corporation's decision to cap the scheme at 4.6 million sq. ft mirrors what the authority had in mind, so they have gained nothing from their decision to take it through the normal planning process. Furthermore, of the 26 buildings proposed in the voluminous planning application lodged last April, full planning permission has been granted for just two - the conference centre and a single adjoining office block. Even this is conditional on the submission of an immense amount of further details.

It is evident from the corporation's decision that its planners were not prepared to rely solely on the international reputation of the Irish-born US-based architect, Mr Kevin Roche, to get the details right. Moreover, in granting only outline planning permission for the remaining phases of the scheme, they have rejected his master plan.

The chief planning officer's report is quite scathing in its assessment of this plan. Mr Roche's office had proposed "a somewhat anonymous style of speculative commercial architecture which in total, it must be said, produces a rather low-key, bland appearance provoking images of North American city core development".

The most significant sentence in the 32-page planning decision reads as follows: "The layout proposed, including all details of buildings, structures, open spaces, paved areas, circulation areas and access points, are specifically excluded from this grant of outline permission." In other words, it's back to the drawing boards.

The corporation's decision is also a slap in the face for CIE. Its primary role as the national transport company was clearly subservient to the real estate imperative of extracting as much value as possible from its Spencer Dock site. That is why the transportation elements of the scheme made little or no sense.

Firstly, there was to be basement parking for more than 6,800 private cars. Secondly, the scheme made provision for just one track for a Luas light rail line through the site and, thirdly, the critical strategic issue of providing a new cross-river rail link from Spencer Dock to Barrow Street, on the south side, was left unresolved.

One of the main reasons why only outline permission was granted for most of the scheme was that it could not be allowed to proceed "pending a decision by the competent State authorities in relation to the vertical and horizontal alignment of the cross-river rail link", as recommended by the Greater Dublin Strategic Planning Guidelines.

CIE was appalled to learn that its own light-rail project office had lodged an objection to the plan, arguing that the provision of just one track for Luas on Mayor Street would "severely compromise" the system's efficiency. Senior management forced a withdrawal of this objection, but it was taken on board by the planners.

In its decision, the corporation specified that adequate provision "shall be made to facilitate a future double-line, light-rail track through the site". This was considered prudent to cater for a "crucial transport facility"; the proposal for a single-line track "is not acceptable as it would not meet the demands of the area", it said.

The corporation has also drastically cut car-parking on the site from 6,805 spaces to a maximum of 2,000, as well as insisting on a "mobility management plan". However, given that 1,800 of these parking spaces would be taken up by residents of apartments, that would leave just 200 for everything else, including the National Conference Centre.

There is also ambiguity over the issue of building heights. The chief planning officer recommended that no building at Spencer Dock should exceed a height of 54 metres. However, the city architect, Mr Jim Barrett, said he believed that higher buildings could be accommodated in the middle of the site.

This apparent disagreement may be resolved by a high-buildings study which the corporation is commissioning to identify those parts of the city which could take taller structures. The guidelines set by this study would act as a pointer to Mr Roche and his team, giving them "some design flexibility", according to the planning decision.

An Taisce has rightly attached great importance to the outcome of this study and will be lobbying to ensure that it takes on board the views of amenity and community groups. It also believes the study is likely to result in significantly less than the 4.6 million sq. ft of development on the overall Spencer Dock site. Mr McDonnell is anxious that the conference centre, which would be 45 metres high to parapet level, would "retain its dominance as a landmark building" instead of being almost overwhelmed by tall buildings stacked up behind and beside it. The tilted cylindrical atrium, its most striking design feature, would be almost as high as Liberty Hall.

Given the corporation's decision to scale down the overall scheme, to the extent that funding the centre is a "financial impossibility", the developers are certain to lodge an appeal with An Bord Pleanala. Many of the other parties who made submissions to the corporation objecting to the scheme are also likely to join in.

The Spencer Dock scheme is so enormous and the planning issues involved are so complex that it is bound to take at least six months to process these appeals. Further delay also runs a real risk that the £26 million earmarked for the conference centre by the European Commission could "fall by the wayside", as the developers have warned.

In the wake of the corporation's decision, a spokesman for the developers told The Irish Times they would seriously consider any initiative by the Government to provide public funding for the National Conference Centre in compensation for losing 25 per cent of their development plan. Indeed, without such an initiative, the project may be doomed.