Tens of thousands of high-rise apartment buildings around the world are in serious need of love today. But how do you rejuvenate these tall buildings often stuck in increasingly dense metropolises? A Quebec company believes it has the solution.

Passers-by in downtown Montreal will probably not have noticed it, but a tower in the Complexe Maisonneuve has been undergoing a major facelift since last spring. Its exterior shell will be completely renovated: new siding and new windows, with enhanced insulation along the way.

Where are the workers? They are housed in a large, two-storey nacelle that completely encircles the 28-storey skyscraper, inaugurated in 1983. The exterior covering of the shelter, made of polycarbonate panels, allows it to blend in almost elegantly with the ‘building. Attached to the roof, the structure descends little by little as the work progresses.

A freight elevator, integrated into the nacelle, allows workers to go incognito to the site without going through the interior of the building. This same freight elevator allows materials to be transported and waste to be removed discreetly. “No noise, no dust, no visual disturbance,” notes Joey Larouche, President and Founder of Upbrella.

This Boucherville company had already made its mark in the world of high-rise construction sites, in 2016, with an unusual construction method: start by building the roof at ground level. Powerful lifting jacks then raise the structure, to which sheltered working walkways are attached, to allow construction of the ground floor.

The floors are thus built one by one. When a floor is finished, the roof and walkways are raised to build the next floor, and so on. The workers can thus always work sheltered from the weather, with both feet on a solid floor.

This method has been used in different places around the world for new construction or the addition of floors, such as at the Germain Hotel in Montreal in 2018. It was also chosen for a social housing building under construction. construction in Monaco, to the delight of the neighborhood of the construction site.

“There, in a single year, the manufacturer had received 600 tickets of $1,000 each for exceeding the sound limit of 85 decibels. He hasn’t received any since installing our process,” says Larouche.

The idea of ​​a closed, minimally intrusive site is now appealing to contractors specializing in the renovation of large buildings.

These tall apartment towers flourished in major cities around the world from the 1970s. In Hong Kong alone, there are tens of thousands, says Joey Larouche. Half a century later, these residential parks show their advanced age: faded materials, end-of-life windows, outdated look or energy-intensive design according to future standards.

Called Local Law 97, this 2019 municipal regulation will require owners of buildings over 25,000 square feet to reduce their carbon emissions by 40% by 2030 compared to their consumption in 2005. They will have to achieve another target even higher in 2040.

In Ontario, Toronto Community Housing has also undertaken an energy improvement plan for its buildings, spread over several years.

In London, a large construction site is also being prepared in the wake of the fire at the Grenfell residential tower in 2017. More than 70 residents lost their lives. The public inquiry had revealed that the fire had started in the motor of a freezer before igniting the exterior covering made of flammable materials.

According to UK media, some 640,000 people across the country live in thousands of buildings with a similar fire risk.

However, in the British capital as everywhere in the world, these once a little lonely towers are now stuck in a tight maze of major arteries, mature parks, cycle paths and other imposing skyscrapers. The complexity of sites increases costs and lead times.

” We do not have a choice. You have to find another way than traditional methods,” says Joey Larouche, who claims that the Upbrella process reduces construction time by 20% and pollutant emissions by 55%.

Upbrella is currently in the running for two major projects: the Montparnasse tower in Paris and the Brittany tower in Nantes. “They are two icons in France. It would be a tour de force for a Quebec company to be part of these projects, “said its president.