Everyone who thinks that third-level students are a cosseted, self-indulgent and smugly middle-class bunch who couldn't give a hoot about social issues should refrain from visiting the new student centres at UCD and DCU. Because these splendid facilities will only confirm their prejudice.

In fairness, every university needs a student centre to accommodate numerous clubs and societies, offices for the students union, multi-purpose spaces for gigs, debates and the like and, of course, somewhere to eat and drink. And in UCD's case, Belfield has been waiting for just such a facility for nearly 35 years.

For it was way back in 1967 that David Watkins Cronin won a competition to design a student union building for the emerging campus. Sadly, however, his plan languished on the shelf for years because it wasn't a major priority for the college administration and, even if it had been, there was no money to pay for it.

So successive generations of UCD students had to settle for a series of temporary facilities. The first bar, which I was involved in procuring, was a Terrapin hut opposite Robin Walker's monumental Restaurant Building; it was eventually replaced by a much larger, more permanent single-storey structure beside the restaurant.

But look at what the students have today - a purpose-built centre of the highest quality, located between the Science Block (Belfield's earliest college building) and the Sports Centre. Though only two storeys high in the main, its overhanging roof and carefully modulated facade give it a real presence in this modernist setting.

It would be fair to say that the new centre has been an instant hit. Designed with great flair by Murray O'Laoire Architects, it was built at a cost of £8 million (#10.1m), using revenue generated by the £50 annual capitation fee paid by UCD's 18,000 students, and officially opened by the Taoiseach, Mr Ahern, two weeks ago.

But even this building took a long time to materialise. Ralph Bingham, the project architect, a graduate not of UCD but of the DIT School of Architecture in Bolton Street, originally designed it in 1991 for a competition; at one stage, before the funding package was finally put in place, he thought it might never be built.

The Student Centre is laid out alongside a beech walk that leads to the entrance of the Sports Centre. Seating spills out from its cafe onto an open, south-facing terrace while a low concrete wall encloses a sunken courtyard to the west where patrons of the lavishly-fitted bar can imbibe outdoors.

Inside, all the facilities - other than the bar, which has a separate entrance - are laid out around a double-height concourse that's filled with light, even on the dullest of days. Under its hull-like perforated beech roof, flanked by patterned windows, this quite stunning atrium has even hosted a rugby club dinner.

The cafe, franchised to La Scala, and the shop add bustle to the concourse during the daytime and the stepped platform at one end, where students lounge around, can be used as a stage for gigs. The Students Union has its offices on the ground floor; upstairs are the clubs, societies and health centre.

An acoustically-panelled multi-purpose hall with retractable bleacher seating for 600 occupies the eastern end of the building, behind an almost blank wall of Staffordshire Blue brick. Capable of being used for debates, concerts and discos, it has a blue-carpeted ante-room on the first floor where guests can be entertained.

The large surface car-park to the rear - Belfield has no less than 4,000 parking spaces - is pre-wired to provide power for a marquee, if required. All of the main spaces in the centre are available for letting through its manager, Dominic O'Keeffe; recently, its bar was the venue for a Moldovan wedding party.

With a population now larger than Sligo's, UCD needs more amenities, such as a swimming pool. In the meantime, nobody will run out of places to drink; apart from the Student Centre, there's the staff common room in the Arts Block, another bar in the Sports Centre and the old Students Club bar.

DCU is fast catching up. Its extended Student Centre now has two bars, one - tricked out, pathetically, in neo-traditional style - in the original, rather congested building and the other in the bright new extension by Anthony Reddy Associates. And if they're not packed these days, it's only because of exams.

The design of the extension had to be put to a student referendum in the autumn of 1999, which must have given its architects a few heart-stopping moments. Fortunately for this fastexpanding university on Dublin's northside, it was carried and the students are so pleased with the outcome that it's been dubbed "The Hub".

Old and new are joined together by a double-height, toplit atrium, or "inner street", attractively serpentine in shape, which provides a new route from DCU's impressive central quadrangle to a developing student housing quarter at the rear. Painted in vibrant colours, the atrium is a dynamic space that's always in use.

Though the academic blocks on the north side of the vast, landscaped quadrangle are three storeys high, Arthur Gibney and Partners' original Student Centre is mainly single-storey - and much of that is occupied by a convenience store. The new extension adds a bar-cafeteria, offices, a bookshop and multipurpose hall.

More boxy than UCD's version, this hall also has retractable bleacher seating so that it can be used as a theatre or debating chamber or, conversely, as a disco when the floor is cleared. Large timber shutters open into the space from the bar/cafeteria, presumably to envelop everyone in whatever fun might be going on.

Built at a cost of £3.5 million (#4.45m), the extension provides open-plan and cellular offices as well as meeting rooms on its upper level. It was also built to leave open the option of adding another floor later, if required; ideally, this should be added to the original building to bring it up to a scale appropriate to the formality of the quad.

The new entrance is marked out by a canopy and glazed curtain wall, flanked by banded stone on one side and a circular brick tower on the other, part of the original building.

Dundalk Institute of Technology also has a new Student Centre, designed by Murray O'Laoire, though on a more modest scale than either DCU or UCD. Inevitably, perhaps, it shares some of the features that characterise the Belfield building, such as an overhanging roof and a projecting first-floor box (a gym in this case).

In the midst of all the development of new student facilities, it is ironic to note that the daddy of them all - the Students Union at Queen's University in Belfast - now faces demolition, even though it merits listing as a good example of 1960s architecture; London based Dixon Jones Architects have won the job of replacing it.