Would architect Patrick Keely be spinning in his grave at the changes awaiting his magnificent Holy Trinity Church? Or would the Tipperary-born builder understand that times change, and be grateful that his artistic vision will remain at least partly intact on the South End corner that the church has graced since 1877?

Developer David Goldman and his company, New Boston Ventures, purchased Holy Trinity Church, at 136 Shawmut Avenue, from the archdiocese of Boston. Although the church cited severely declining attendance as the reason for the sale, the moves came amid other sales of church property in which the money went to paying damages incurred from the abuse scandal.

The Boston Redevelopment Authority has granted the developer permission to redesign the edifice, dubbed the “German church” because it tended to the rising numbers of German immigrants in the 19th century, and rectory into at least 33 boutique condo units. Much of the church’s interior will be demolished and an 8-story, 58,000-square-foot modern steel-and glass structure will rise on the site. The developer has assured the city that Keely’s graceful spire and classical architecture will remain a highlight. Perhaps, but it raises the time-old issue of progress versus preservation.

Patrick Keely understood progress. His soaring churches and cathedrals – including nearby Holy Cross Cathedral – still soar above the landscape from the East Coast to the Mississippi, in places like New York, Charleston, Chicago, and Milwaukee.

He was lauded by his eulogist for how he changed the social, religious, and architectural landscape of Boston and beyond: “The largely Irish congregations who in their native country were forced to attend Mass on an open hillside, a rock serving as an altar, and with men on guard to watch for the coming of soldiers were quite content with a space for the altar and a roof over their heads. Keeley [sic.] was able and gave them more…”

While Keely’s early years in the town of Thurles in Tipperary remain murky, historians speculate that his family was fairly well off. According to town records, the Keelys lived in a home “that had been occupied as a convent by the Presentation sisters and which had been built by a wealthy distiller named McCormick. Apparently young Patrick received the education available to boys that were expected to be tradesman and mechanics.”

Keely immigrated to Brooklyn in 1842 and initially made his way as a carpenter. In an era when master builders devised their own construction plans, the lines between architects and gifted tradesmen could become blurred, and tradesmen without formal academic training nonetheless designed and built structures. Still, the formal practice of architecture was taking shape in America as young Keely started his career.

His presence in Boston began in earnest in 1851, when he tackled the renovations, rebuilding, and enlargement of the Church of Saints Peter and Paul in South Boston. The granite Gothic Revival church had been designed by Gridley J.F. Bryant in 1843 and completed in 1845, but had been heavily damaged in a fire in 1848. Keely, hired to restore and expand the structure, completed his work in 1853.

The impressive results of his renovations on the South Boston church led to numerous commissions from the Boston archdiocese, and Keely oversaw the construction of his houses of worship from blueprints to spires. More than twenty of his churches still stand in the South End, Dorchester, East Boston, South Boston, the North End, Charlestown, Roxbury, Hyde Park, Brookline, and many other Massachusetts cities.

After his death, in 1896, his sons and son-in-law continued the firm of Keely and Houghton. Their projects including St. Margaret’s Church in Dorchester (1899–1904) and St. Mary’s School in Charlestown (1901–02).

While the hundreds of churches Keely designed testified to his skills, his cathedrals – his vision on a grander scale – cemented his reputation as one of the greatest neo-Gothic architects of the era. Some of his smaller churches were built on such a scale that they were nearly cathedrals themselves. In 1884, the University of Notre Dame bestowed its second annual Laetare Medal on Keely for “changing the style of ecclesiastical structures and modified architectural taste in this country.”

In Boston and beyond, Patrick Keely’s reputation for getting his designs right and rendering them with the highest professionalism and integrity led to an admiring adage among tradesmen: “It must be true since Mr. Keely says it is.”

This past spring, the architect James Alexander, leader of Holy Trinity’s redesign team at Finegold Alexander + Associates, told Boston Globe correspondent Dan Adams “You could tear it [Holy Trinity] down and start over, which would be a tragedy. You’d lose the details, the social and religious history. But re-using it as it was, with the shape of the roof and the square footage, it just wouldn’t generate the return.”

One can only hope that Alexander and his associates do not forget another sort of return. Every time that anyone with even a passing interest in Boston’s history stops and looks at Holy Trinity, the Cathedral of the Holy Cross, or any of Patrick Keely’s churches, they view the literal landscape of Keely’s genius and his historical impact. The toniest of condo developments pales in comparison.