Ask Dubliners about their favourite architecture and chances are most will mention TCD. The college's elegant, classical west front, built of Wicklow granite and Portland stone, has dominated College Green for almost two-and-ahalf centuries; behind that, Front Square is an oasis of calm in the centre of the city's traffic chaos.

Trinity's director of buildings, Tim Cooper, says it is unique. "It's the only collection of buildings in the heart of a city that has remained undisturbed for 400 years," he says. TCD has grown enormously in recent times - in student numbers and size. The college now owns almost the whole of the "island" site surrounded by College Green, Nassau Street, Westland Row and Pearse Street; the only exceptions are the Dental Hospital at Lincoln Place and one small building in Pearse Street. Trinity is also bursting those island boundaries: eastwards down Pearse Street, beyond Westland Row - a large site between Cumberland Street South and Sandwith Street is the proposed location of a new sports hall; and westward, too - properties in Foster Place, just beyond the Bank of Ireland, have been acquired. In six years TCD has spent £55 million on new developments.

The Pearse Street developments include sites which now house the Samuel Beckett Centre and the student health centre and creche. A glass concourse links the new O'Reilly Institute and Hamilton Building with old properties on Westland Row. The school of pharmacy and the department of genetics are in a new building at Lincoln Place. A major new entrance to the college is planned for the corner of Pearse Street and Westland Row, where an underground car park is also to be built. This site will also contain a new computer science and statistics building. The proposed new library, facing Nassau Street, will be linked to both the Berkeley and Lecky libraries.

Trinity's 18th century buildings were built to rival those of the Oxford and Cambridge colleges. The college employed distinguished architects including Richard Cassels, who designed the Dining Hall, and Sir William Chambers, who designed the Exam Hall and the Chapel. Given that the older part of the college has set extremely high architectural standards, how have newer areas fared? "We take architecture seriously," Cooper says. Architects for new projects are chosen by open competition. "The college is managed democratically and a great deal of discussion and debate about our plans and the design of our buildings goes on." Architects, he notes, clamour to work on college projects in order to enhance their CVs.

The Berkeley Library, designed by Paul Koralek and built in the 1960s, is an undoubted success. More recently, Parson's Podium, designed by Grafton Architects, has been the subject of much acclaim. Aras an Phiarsaigh on Pearse Street, a dreary modern building formerly occupied by the Revenue Commissioners, has had a facelift at the hands of architects Mahoney and O'Byrne. The new Goldsmith Hall, which adjoins Pearse Station, is less successful. The rather grim, limestone-clad building provides a multi-purpose theatre and student accommodation. At ground level, huge roller shutters only serve to underline the bleakness of the streetscape. The original plan for the building included a row of shops on Pearse Street to be rented by CIE - hence the shutters. "The shutters are there for security reasons," says Cooper. "We would prefer to keep them open if we could." Walk around the campus and it's wonderful. Examine the peripheral properties, though, and you'll be less than impressed. Take Westland Row, where the whole terrace is occupied by the college. Formerly home to Dublin's haute bourgeoisie (including Oscar Wilde), the row of houses has an air of dilapidation. Paintwork peels, windows and doors ooze grime.

"When we acquired the buildings they were becoming derelict and as a result of a road-widening scheme were due for demolition. When the city's development plan was changed we were allowed to retain them." The terrace's interiors have recently been refurbished, he says, and the exteriors are shortly to be redecorated. However, Cooper warns, "the environment in the city is terribly severe and our resources are limited - we simply can't afford to keep them gleaming." Pearse Street similarly offers a gloomy prospect - dirt, grime and, in this instance, bricked-up shop windows. The street, Cooper admits, "is a very inhuman space. It's a massive traffic highway, which results in a classic canyon effect." TCD's Development Control Plan (1995) clearly states that "the redevelopment of the existing houses must also improve the appearance of the College on Pearse Street". Even if the surrounding areas remain derelict, surely it is TCD's duty to ensure the face it presents to the world - on all sides - maintains the high standards the college has set for itself on the west front and elsewhere on campus?