It may be hard to get a sense of the building that now looks like a giant abandoned carpark. But when it was first opened in the mid-1960s, St Peter’s seminary in Cardross, near Dumbarton, was recognised as a highly visionary and forward-looking piece of architecture.

The firm of Gillespie, Kidd & Coia were commissioned in the early 1950s to design a replacement for the old seminary building which was damaged in a fire in 1946. Plans were finalised in 1961, and construction completed five years later. Filled with timber and glass throughout the modern concrete shell, the building was designed in the brutalist style.

Images of the building when completed in 1966 by architectural firm Gillespie, Kidd and Coia. Photographs: GSA Archive

St Peter’s College exterior. Photographs: GSA Archive

The decline of the Catholic church in Scotland meant that the building never fulfilled its intended use, as there was an insufficient number of students for it to operate as full-functioning seminary. Chronic problems with building maintenance have been attributed to the unusual design and remote location.

It was closed officially as a seminary in 1980, and was used throughout the following decade as a drug rehabilitation centre, although most of the patients had to be accommodated in the adjacent Kilmahew House, owing to the maintenance problems. The modernist buildings were A-listed in 1992, though a fire in 1995 led to Kilmahew House being demolished after it was declared unsafe. The rest of the site has lain unused since then.

The view from the upper floor of the central chapel as it is today.

In 2005, the architecture magazine Prospect declared St Peter’s Scotland’s greatest postwar building, and. There have been many attempts to restore and redevelop it. Plans have included building a 28-unit housing development in the grounds.

The brutalist style was not universally popular.

In 2007 it was announced that the former seminary was to be included in the World Monuments Fund’s 100 most endangered sites list. Later that year, the developer Urban Splash became involved, working with the architect Gareth Hoskins, and in 2009 the environmental arts group NVA were awarded a grant by the Scottish Arts Council to develop temporary and permanent artworks as part of the redevelopment of the building and surrounding woodlands.

In 2011, Urban Splash pulled out owing to viability issues. and the archdiocese of Glasgow reiterated its view that no commercial scheme would be viable for the site. ERZ landscape architects applied for planning permission for a site focused on regeneration in 2013. The National Lottery Heritage Fund helped initiate a major cleanup of the site in 2016, and that year the environmental and public art collective NVA stage a sellout 10-day a sound and light event.

NVA’s Hinterland in Performance in 2016, St Peter’s Seminary.

NVA hoped to make it a cultural centre but the plans never got off the ground. This month, the Catholic church, which still owns the site, said the building had been degraded by fire, rain and vandalism and described it as a “ruin”. Ronnie Convery, the director of communications for the archdiocese of Glasgow, said the building was an “albatross around the neck” of the archdiocese, which has theresponsibility to maintain, secure, and insure it. The archdiocese could not sell, give away, or demolish the A-listed building, he said, adding that public funding was the only way forward.

Graffiti now adorns the concrete through the shell.

“If someone were to go today through the forest and try to find this A-listed masterpiece they would probably be shocked because it looks to an average person, who does not have a lot of architectural background, a bit like a concrete car park that has fallen into ruin,” said Convery. “For those who understand such things, the brutalist architecture of the day, the materials used, were unique.”

On the concrete structure remains. The staircases and bannisters were timber, and there was wood panelling throughout. Photographs: GSA Archive

He added: “It draws heavily from Le Corbusier’s work in the south of France and was part of the Gillespie, Kidd and Coia empire and is considered the best of their works. Therefore it is a significant building for the nation and probably one that needs public money to survive.”

The convent block now, and when it was first completed.

A Scottish government spokesman said: “In the first instance, the future of the building is a matter for the archdiocese of Glasgow, who own the building. Scottish ministers asked Historic Environment Scotland for advice on potential options for the future of the former seminary, and the wider site. This is under consideration.”