Lina Ghotmeh has focused her career on sustainable construction.

The Franco-Lebanese architect wants to transform her industry by drastically reducing the use of concrete – a major CO2 polluter – by using more local materials and reusing existing buildings and materials.

“We need to change our value system,” the 42-year-old told AFP last month.

The aim is to reduce the carbon footprint of the construction industry and create buildings that are better able to withstand the effects of climate change.

But it’s not an easy fight.

According to the United Nations, industry is responsible for almost 40 percent of global greenhouse gas emissions.

Ghotmeh, who designed the Estonian National Museum and taught at Yale University, isn’t advocating fewer buildings — she knows that’s an unrealistic goal in a world with a growing population.

“That would be like saying, ‘Stop eating,'” she said.

Instead, we should “retain what already exists, not tear it down”, but renovate and retrofit old buildings as sustainably as possible.

According to the French Agency for Ecological Transition (Ademe), the construction of a new family home uses 40 times more resources than the renovation of an existing property, and for a new apartment complex even 80 times more.

And where new construction is needed, local materials and designs should be used in a way that incorporates the natural environment and conserves energy.

Ghotmeh used more than 500,000 bricks from local soil for a new Hermes building in France, due to open early next year.

The bricks also regulate the temperature of the building and reduce energy requirements.

The building will produce as much energy as it consumes by making it energy efficient and using geothermal energy.

Architects need to “think circularly” at the beginning of the project process, Ghotmeh said, opting for reusable organic or natural materials such as wood, hemp, canvas or stone.

That shouldn’t get in the way of the design process either, she stresses.

“In Canada we build wooden towers, in Japan too. This is a material that is definitely suitable for tall buildings,” adds Ghotmeh, who will build a wooden tower in Paris in 2023.

Another important approach is to build lighter, use less material and less toxins.

And then there’s concrete, the main material in so many modern buildings and perhaps the most difficult to move away from.

“We need to drastically reduce the use of concrete,” she said, insisting that concrete should only be used for essential purposes like foundations and buildings in earthquake-prone areas.

According to the Global Cement and Concrete Association, around 14 billion cubic meters of concrete are used every year.

It emits more CO2 than the aerospace industry, largely because of the intense heat required to manufacture it.

Alternatives to concrete already exist, such as stone or making cement – a component of concrete – from calcium carbonate. There are also pushes for low-carbon cement made from waste from the iron and steel industry.

Greener building often comes at a higher price – it costs more to double or triple glaze windows and properly insulate a home – but the long-term benefit is lower energy bills.

For Ghotmeh it is a compelling investment in our future.

It was her birthplace, Beirut, that inspired her to become an architect and a desire to rebuild the so-called “collapsed city” devastated by war.

In 2020 she completed the “Stone Garden” residential tower in the city, built of concrete and covered with a combed coating, a technique commonly used by local artisans. Because of the risk of earthquakes, they used concrete in the construction.

The building was strong enough to survive the 2020 port explosion that destroyed much of the city.

And the city still inspires her today, also when it comes to climate sustainability.

“Since there is practically only one hour of electricity per day, all buildings now have solar panels. There’s a kind of energy independence that’s inevitably emerging,” she said.

“Does it take a disaster like the one in Lebanon to make that transition?”