An Irish solution.

A new British Embassy built in a leafy suburb of Dublin is a restrained and dignified presence, a modern evocation of the eighteenth-century Irish house and an enlightened yet appropriately formal place in which to work.

The new British Embassy, designed by Allies & Morrison, in the Ballsbridge suburb of Dublin, is crisp, formal, distant, courteous to its neighbours and respectful of local tradition and custom - all of which qualities, were they possessed by one man or woman, would make an excellent ambassador.

The main public facade of the embassy, stone-faced under a grey slate roof, faces north-east on to Merrion Road and the building, really a complex of parts, stands well back within its own gardens behind a gatehouse and palisaded wall. The site on the northerly side is occupied by an extravagant and desolate Victorian pile, but the area is predominantly one of red brick Edwardian family houses. Two on the site immediately to the south-east were converted into embassy offices after those in Merrion Square were burned down in 1972 in the aftermath of Derry's Bloody Sunday. Over the years, these buildings became increasingly cramped and expensive to maintain, and by the end of the '80s, it was plain that new premises were needed. The adjoining site was bought from the Royal Dublin Society whose showground is behind the embassy.

Building the embassy in a leafy Dublin suburb inevitably imposed constraints; but in juggling competing demands, Allies & Morrison have arrived at an architecture that exists without compromise in its own right, with a degree of grace and internal delight. Clear expression in good Modernist tradition (function, structure or material) and thoughtful detailing have been characteristic of this practice's work in the past, and the articulation of hierarchical orders and layering of space to indicate degrees of formality and ceremony are devices that these architects understand very well.

For reasons of grandeur, convenience and security, embassies are prone to occupy large defensible mansions, and the practice's restrained adoption of the model of the eighteenth-century house in Eire, with gardens and stable yard, suggested an ordering and scale which makes the building intelligible while marking the fact of its formal presence in its surroundings.

The embassy is T-shaped in plan, the stem of the T meeting a line of single-storey offices at the back where there is a staff entrance and leafy car park, designed in the spirit of an old stableyard and approached from the direction of the showground. Conceived as this cluster of interconnecting buildings of varying heights, the complex is disposed in Classical manner around a central courtyard, as are many important public buildings in Dublin. Following the city's architectural convention, stone signals the formal and public and brick the informal; the use of the latter for garden walls and rear offices also constitutes a courteous nod in the direction of neighbouring buildings.

The main building facing Merrion Road contains the embassy proper and the consular and visa section, the two parts, each with its own entrance, being made distinct. In elevation, the former is indicated by the facade of a symmetrical five-bay house with the central ceremonial entrance emphasised by a chimney stack and coat of arms. To the right is its extension, a three-bay wing with a more informal public entrance to the consulate. The building's internal organisation - but not its character - is hinted at by its tripartite division into base, piano nobile and attic, with the structure's piers and floors expressed by a trabeated metal grid. A continuous band of clerestory glazing represents the attic so that the massive slate roof oversailing at the gables appears to be floating on air.

The building envelope was conceived as a skin with layers that can be peeled back to reveal the layers beneath. In spirit, more a Soanesque device than a simple conceit, the peeling helps to dissolve mass and animate surface. Manipulation of the skin creates other illusions. As in the practice's design of the Scott Howard showroom in London, metal cladding extends window openings while maintaining the 1.5 m planning grid. Looking at the building from a distance, the apparently solid granite walls and long line of the floating roof predominate. Close to, the granite appears to suggest a subcutaneous metallic layer.

Viewed as a workplace, the embassy is immensely civilised, surrounded as it is by gardens in which Allies & Morrison's screens are part of the sculptural composition. Made of brick or stone, sometimes juxtaposed or perforated, to suggest far, middle and near distance, their part in forming the landscape evokes Barragan. Visitors to the consulate and visa section cross a stone bridge over an elegant elongated stretch of water, like the trace of a moat, within which Susanna Heron's quiet slate sculptures are meant as emblems of peace. The building skin of Wicklow granite has been cut away to create an open porch of Portland stone with a stone seat inset for contemplation.

Having parked their cars, the staff pass through a portal into the internal delight of the central courtyard. This, the kernel of the embassy, is defined by planes of white stone and red brick, with planted borders, lawn and trees. From it there is access to the various different quarters, and to the main central hall which rising clear and white to the height of the floor above has a glazed wall onto the courtyard.

Corridors run off in several directions to offices and to the consulate's reception and waiting room. You climb a delicately detailed staircase to the first floor and an open gallery which furnished with easy chairs can be made private by folding wooden screens. At the upper level of the hall, Susan Kinley's silk hanging shimmers in the light.

The interior is characterised by a lack of pomposity and, say the staff, its apparently simple organisation reflects the logical workings of each department and their interrelationships, making life a great deal easier. Offices equipped to modern standards are high-ceilinged, white-painted airy spaces with lighting concealed by suspended panels. As is typical of this practice, interior and exterior are conceived as interrelated, flowing through glass walls or slots cut into opaque ones. Portland stone used for paving and framing in the gardens is carried through into the public parts of the interior, paving the floors of the Ambassador's main entrance hall, the two waiting rooms and corridors. Stone gives way to powder blue carpet or white American oak in the various offices and apartments, depending on the degree of informality. The initial assumption that for security reasons, the building would have to be sealed and air-conditioned was dispelled by the architects with the help of Max Fordham, and it can be naturally ventilated by means of louvred screens and shutters.

This is an accomplished and academic building, in which detailing and immaculate craftmanship are a constant pleasure. In passing in and out, you are made particularly conscious of heavy duty steel and glass and the burden of security. By architectural sleights of hand, Allies & Morrison have mostly made light of the fortifying measures, which confronted daily can be dispiriting. But such fortifications must be the reason why this building appears to keep its distance. It seemed ironic at the time, that just as the embassy was completed, the IRA cease-fire was declared. It seems ironic no longer.