This old Victorian home has a secret: it's part of the Montreal Metro system

Unlike its neighbours, the house at 1423 Towers St. in downtown Montreal seems to have withstood the test of time. While its stone Victorian walls appear unchanged, the building itself is hiding a secret: it's not a house at all — at least, not anymore. 

For years, Montreal's transit authority has been discreetly building a sprawling ventilation system within — and below — the abandoned building. Behind its snow-crusted front steps lie the hidden depths of the city's Metro system.

The STM said it chose the old house for its ventilation station because land is scarce in the downtown core, especially near the Metro's Green line, under de Maisonneuve Boulevard.

Martin Allard, an architect with the Société de transport de Montréal (STM), said the house was built as upper-middle class Montrealers moved closer to the city's Golden Square Mile.

"It was important for us to preserve it, that spirit, of what it was like in that era."

Allard explained that the building had been empty for decades, often used by squatters and in disrepair. The wooden structure wasn't salvageable and little of the original interior was left intact behind the stone walls, he said.

To make sure it was rebuilt properly, the STM scanned the front of the building, numbering each stone and marking its place on the facade so it could be rebuilt exactly as it was. The outdoor woodwork was rotten, but a craftsman was able to make identical replacements, Allard said.

The original stained glass window above the door was restored. Allard said they had to dig through 364 layers of paint to find the original colour of the wood frame — it was green.

Finally, to perfect the illusion, lighting was installed in the front hall, so the home looks inhabited.

"It looks believable," Allard said. "People even leave flyers on the porch, and we have to make sure to remove them once in a while!"

But the illusion ends at the front door. Pushing it open, one is met with a gaping concrete stairwell — one that descends 18 metres underground, into the tunnels of the Metro system.

Up above, an opening — disguised in the original's house's roof — lets sunshine and snowflakes tumble in.

"To the left is the tunnel that will go to the Metro," explained Éric Perreault, a project director with the STM. At the bottom of the tunnel are huge fans and silencers, recently installed.

Perreault said there are three functions of a ventilation station: to bring in fresh air in, especially on hot summer days; to exhaust the fumes from diesel equipment used at night; and evacuate smoke in case of a fire.