A recent feature in The Irish Times described the former Bord Fáilte headquarters, at Baggot Street bridge in Dublin, as a "rundown site". Many people might indeed consign it – and modern architecture in general – to a "failed" moment, condemned as passé or even ugly.

While technically the building might be seen as “rundown”, not least because it has been unoccupied for eight years, the observation points to a widely held perception of mid-20th century architecture in Dublin.

The building has always been dogged by controversy but despite this it is part of our heritage, more than 50 years old, and stands as a built record designed by one of our most celebrated architects of that time, Robin Walker.

Even more important perhaps is the questionable validity of knocking down a building that could clearly stand for at least the next thousand years and replacing it with another building. If we were to adopt that attitude to our Georgian heritage, much of which is architecturally unremarkable and in a much poorer physical condition, our cultural environment would suffer disastrously, eroding our built legacy.

One does not have to be an architectural historian to foster an appreciation of our mid- 20th century architecture: it requires no more than a passing interest to make the mental connection between these buildings and a world of thinking and design.

The Bord Fáilte building was completed in 1961, at a cost of £50,000, soon after Walker’s return from Chicago, where he had studied under Mies van der Rohe. In a paper delivered in 1968 he said: “We need to ensure that our buildings . . . and works of art fit together to express visually and intellectually a harmonious reflection of our society and its age.”

One could perhaps infer from his words a distinction between “our society” – Ireland in the 1960s, with all of its proximity to nature, strangely absent industrialisation, religious iconography and poverty of material – and “its age”, which presumably extends to a global reality. In other words, he may have immediately, on his return from Chicago, saw the Miesian prescription as applying to the task of inventing a local architecture that responds in a nuanced way to its context.

A simple reading of Bord Fáilte as a reworking of modernist language or form in an Irish context is incomplete. Its architecture might just as accurately be described as postmodern – as a way of thinking about time and of the city, and of the value of the city over the unitary built artefact.

It is located at a natural node point, in terms of Dublin’s’s urban plan, and fulfils the requirement for a stand-alone object or building at this point, completing the sweep of the Baggot Street terrace where it meets the Grand Canal.

It has variously been claimed it was the first core- plan office building adopted in Britain or Ireland and the first use of fair-faced concrete in an Irish office building. Undoubtedly there are other devices also derived from Mies, in particular his buildings at the Illinois Institute of Technology.

But here, the raised ground floor and the projecting entrance steps correspond exactly to that of the Georgian house; and the basement storey, with its extended courtyard to the rear, is derived from the Georgian basement area, providing a quiet, private, exterior space for the building’s occupants, away from the street.

The building testifies to an appreciation of the Georgian vernacular, especially Walker’s concern to build at low-cost in the same spirit as the Georgian terrace.

As the load-bearing front wall of the Georgian is flat and unadorned, so Walker exposed the plain, load-bearing concrete frame of the modern, perfectly detailed. As the proportion of the Georgian bay is vertical with openings at the maximum limit of what the structural wall could allow, the building uses the essential defining proportion of modern structure: the horizontal bay uniquely afforded by reinforced concrete.

As the Georgian terrace culminates at its top in a single course of plain granite, so its parapet is straight and flat and aligned with the level of the Baggot Street parapet; and as the terrace uses for the most part basic bricks made on site with local material, so does Bord Fáilte use the humblest of all modern, local materials – the grey stock brick.

Of course, buildings must evolve over time - in the case of Bord Fáilte, it would be relatively simple and inexpensive to remove the non-structural internal partitions, upgrade the heating system and instal double glazing. But the basic architecture is still in a remarkably perfect condition, as any closer examination will reveal.

Bord Fáilte represents an essay in the modern vernacular – no less important for its humble appearance than those more ostentatious contemporary office blocks that rely for effect on expensive façades and high-tech finishes. Beauty may not always be in the eye of the beholder, but objective criteria should also apply.