David Page, head of architecture at Page/Park, said it was unclear if the firm would be able to use the same materials sourced by Charles Rennie Mackintosh for his masterpiece.
The Glasgow-based practice, which has previously carried out work at the Mackintosh-designed Hill House in Helensburgh, was chosen last month to lead the multi-million pound restoration project.
The building in the heart of Glasgow city centre was ravaged by fire in May last year, causing extensive damage to its celebrated interiors.
With work due to begin on the building next spring, the firm is holding discussions with the school about how best to approach the project.
Professor Tom Inns, director of the school, appeared to signal an end to debate about the future of the iconic library by saying that it would be reconstructed.
While opinion is divided in architectural circles over whether to reinstate the damaged parts of the building faithfully or pursue a more contemporary design, Mr Page believes enough is known about the library to reconstruct it.
However, he has admitted that approach may be made difficult due to the way it was built. He said yesterday that the library had been constructed in an extraordinary way and had been “nailed together like a garden fence”.
The practice, he added, was “looking forward to the dialogue” with the school over what to do with the building, but said it would be a “challenge” to see whether the new library could utilise the same materials such as oak and timber from New Zealand.
Others in the architectural community, however, believe it will be in keeping with Mackintosh’s spirit by pursuing a bolder vision for the school.
Rory Olcayto, editor of Architects’ Journal, Britain’s leading architecture magazine, urged Mr Page and his partner, Brian Park, to ignore the “heritage bores” calling for the creation of an exact replica.
He said: “If the school of art is to be the ‘Joycean exercise in exploring the life of a city’ that Mr Page clearly wants it to be, his team will have to muffle their ears when heritage bores insist on authenticity. Joyce was a deviant. So was Mackintosh. Neither conformed to popular taste.”
By taking risks, he added, the practice would “be faithful to both Mackintosh and the city of Glasgow”.
Mr Park said last month he could see no reason not to stay true to the vision of Mackintosh.
“We keep coming back to what we know. We know a huge amount of detail about the library, so it can be reconstructed. So why not?” he said. “If we had no records, we could be in support of a contemporary interpretation but we do have so much. But I understand architects – even in Glasgow – saying they are quite vehemently against this approach.”
The restoration of the internationally renowned school will require the production of 1,100 drawings and 20 hand-made models, Mr Page has said.
The project is expected to cost up to £35 million. It is hoped staff and students will be able to use the building by the 2017-18 academic session, with work completed by 2020.