The overlords of Mirabel Airport have given the green light to demolish an unused terminal that has cost $30 million for minimal maintenance over the last decade.

“We’re at a point that there are some major repairs required, the roof is showing signs of deterioration, if we don’t repair the roof it’ll cave in,” said Aeroports de Montreal President and Chief Executive Officer James C. Cherry at the ADM public annual meeting.

The ADM has attempted without success to re-purpose the 15 acre building since it was vacated in 2004.

The 6,000-acre airport belongs to Transport Canada, which has also given the thumbs-up to the demolition.

The authorities will take tenders for the demolition contract and the final approval for the granting of the contract will come in September.

The building requires an estimated $15 million in repairs, while an upgrade of the entire terminal would cost an estimated $36 million.

Even if the upgrades were done, the building would still be stuck with an “unorthodox interior layout, ceiling heights that are either too high or too low, an energy-inefficient glass envelope, and high levels of asbestos,” according to a press release issued Thursday morning.

In spite of the bad state of the building, the aerospace industry is booming in the Mirabel area, with 3,700 people employed by such companies on the Montreal-Mirabel airport lands.

The Bombardier CSeries project is expected to make that total grow further.

Cherry noted that ADM will invest $100 in the Montreal-Mirabel facility in the next few years including a $40 million upgrade of Runway 06-24. He noted that tenants are also investing in the airport.

Construction started on the airport in 1970 and was completed in October 1975 at the cost of $500 million.