Sam Stephenson was arguably the most outstanding architect based in Ireland of his generation; he was certainly the most controversial.

In 1962 he and his partner Arthur Gibney won a competition to design the headquarters in Dublin of Ireland’s Electricity Supply Board. This involved the demolition of a dozen or so 18th-century houses that were in the middle of a quarter-mile streetscape with mountains in the background — it was one of the glories of the Georgian city.

All hell broke loose as the Irish Georgian Society and kindred preservationists flexed their muscles for the first time. Princess Grace of Monaco was among the thousands who signed a petition to halt the destruction. Sir Albert Richardson came from London to lend support. The Sunday Times correspondent wrote that no London vandal had done worse.

Stephenson entered the fray, calling down a bubonic plague on preservationists and asserting boldly that Georgian buildings were not worth keeping. He voiced a crude nationalist resentment towards Dublin’s colonial heritage as well as the self-interest of a new class of native entrepreneur who wished to make a killing out of redevelopment.

Stephenson was one of five sons of a librarian who had taken part in the Easter rebellion of 1916. His uncle was a Jesuit so Stephenson went to Belvedere, the Jesuit school that had educated James Joyce, and played wing-forward for its rugby team.

Stephenson was fortunate to enter practice in the late Fifties when the Irish economy was emerging from stagnation and there were pickings to be had from friends in the Fianna Fáil Government. He canvassed for the future Taoiseach Charles Haughey, helped to raise funds from developers and ran unsuccessfully for the Senate.

When, in 1965, the Central Bank decided that to signal its new importance it needed a building that towered over the financial district in Dublin, it retained Stephenson. He designed a building 30ft higher than the level permitted by the planning authority, hoping it would not be noticed. It was. The row that resulted deprived him of the kudos that he deserved for a remarkable hanging design that had been inspired by the great Irish- American architect Kevin Roche. Stephenson joked that it was his “biggest erection”.

The rich of the brave new Ireland, like Stephenson’s close friend Haughey, preferred to live in old gentry houses so, apart from a commission to build an Irish house for the broadcaster Eamonn Andrews, Stephenson was denied the opportunity to make a mark in domestic architecture. However, buildings for the Irish Turf Board and the Currency Centre of the Central Bank in the 1970s are acknowledged masterpieces.

More controversial were the new civic offices on the old Viking site in Wood Quay, consisting of four bunker-like towers, a design that owed something to Stephenson’s admiration for Hitler’s architect, Albert Speer. The city fathers took fright at the outcry after two of them were built and brought in other architects to complete the job. Stephenson comforted himself by proclaiming that the great architects of the past had not been appreciated by contemporaries.

Stephenson dabbled in property speculation with developer associates and lived extravagantly. In the lean years of the 1980s this led to financial disaster. As there was little work for architects in Ireland, he dissolved his fruitful relationship with the talented Gibney and set up in London with Stone Toms. Irish developers were pleased to employ him and through his friendship with one of them, the Tipperaryman Ned Ryan, he joined the circle around Princess Margaret.

Stephenson’s marriage was a casualty of the changed direction of his life. Only in 1991, when he married a much younger woman, did he regain domestic stability. He set up home in a Georgian house at Leixlip, near Dublin, and had a second family. He kept up his architecture, albeit in lower key than in his palmy days, and exhibited his well-crafted watercolours and drawings at the Royal Hibernian Academy.

Although short in stature, the bearded Stephenson with his white linen suits and lime-green shirts was always a presence. He was self-assured without being arrogant and was possessed of a delightful ease of manner and ready wit. His instincts were generous. He made friends easily, even with those who had been his sternest critics. A hot-tempered man in need of some forgiveness himself, he bore no grudges.

In later life he expressed regrets for his former abrasive disregard for the great architecture of the past and claimed that he now went to bed with Palladio and woke with Lutyens. But if he abandoned the Modernist faith in architecture he rediscovered his faith in religion and became a daily Mass-goer in recent years.

He is survived by his wife and by six children.

Sam Stephenson, architect, was born on December 15, 1933. He died on November 9, 2006, aged 72.