This boarded-up building lays bare Montreal's crumbling social housing system

The windows have been covered with plywood, the property is fenced off and a "danger" sign warns passersby who might want to trespass.

The building at 5210-5222 Walkley Ave. in Montreal's Notre-Dame-de-Grâce neighbourhood was once a vibrant public housing complex and home to more than a dozen families.

The last of its residents were ordered to leave in 2014, after water damage and mould had made the place uninhabitable.

The city's social housing agency owns the building, and tenants' advocates say it is one of the most egregious examples of the consequences of a woefully underfunded system.

Since the last tenant moved out, the building has been left to fall further into disrepair. 

Byron Cameron, who has lived across the street for 30 years, said people used to meet inside after it had been abandoned. 

In 2015, a fire broke out. At last, the building was secured — but nothing has been done since. 

"It's an eyesore," said Cameron.

"Having that building just sitting idle, and so many people need places to live: it's just a disgrace."

Spanning three city lots, the building once offered 11 three-bedroom units, ideal for families — a rarity in the city's social housing stock.

Montreal's tight rental market has made affordable units like those even more hard to come by. 

Across the city, nearly 24,000 people are on the waiting list for subsidized housing, according to the agency that manages that stock, known in French as the Office municipal d'habitation de Montréal (OMHM).

Côte-des-Neiges–Notre-Dame-de-Grâce has nearly 2,500 people on that list — the second-most of any borough.

Joel DeBellefeuille, who founded the civil rights group Red Coalition, lived next door to the building until last year.