CNN  — 

Monaco may be the second smallest country in the world, but it is also one of the richest. Almost a third of its residents are millionaires, lured to the French Riviera city state by its lenient fiscal policy – income tax was abolished in 1869. It is estimated that 70% of the population is foreign-born, while just 10,000 are locals, “the Monegasques.”

DR: Valode & Pistre
Construction has begun on Monaco's $2.3 billion offshore extension project to reclaim 15 acres of land from the sea.
VALERY HACHE/AFP/Getty Images
Monaco is smaller than New York's Central Park and home to nearly 38,000 residents. Only 10,000 were born locally -- they are known as the Monegasques.
VALERY HACHE/AFP/Getty Images
But the second smallest country in the world is running out of space. Since the early 19th century, Monaco has expanded an additional 100 acres into the sea, accounting for 20% of its total territory.
Valode & Pistre Architects
The planned extension will reclaim the equivalent of approximately 11 American football fields (15 acres) from the sea.
DR: Valode & Pistre
The new ambitious offshore extension project -- Portier Cove -- will house an additional 1,000 permanent residents in luxury apartments and villas.
Valode & Pistre Architects
Additional public spaces will include a hill and landscaped park, a seafront promenade and a little marina.
DR: Valode & Pistre
Private financers will front the $2.3 billion project and are expected to make over $4 billion from the sale of real estate, according to Urban Extension Project Director Jean-Luc Nguyen.
Bouygues Travaux Publics
The extension will be protected by a seawall consisting of 18 concrete-filled chambers -- called caissons.
Bouygues Travaux Publics
The foundation will be filled with quarried rocks and marine sand extracted from northern Sicily.
DR: Valode & Pistre
Prior to construction, protected plant species inhabiting the project area were relocated to nearby marine reserves. A wide variety of artificial habitats will be installed to compensate for the loss of natural habitats.
DR: Valode & Pistre
Once complete in 2025, the sun and sea will provide 40% of the district's energy needs, through the use of solar panels and pumps that use sea water to heat and cool buildings.
DR: Valode & Pistre
Elongated balconies will provide shade from the sun in summer and help recover heat in winter.
DR: Valode & Pistre
The district is designed to follow the curve of the coast so it does not obstruct marine currents.
DR: Valode & Pistre
The plan is to install a Mediterranean landscape of tall pines and other native vegetation in order to make the artificial extension feel more natural.
DR: Valode & Pistre
Each apartment will span over 4,300 square feet (400 square meters), while individual houses will measure approximately 11,000 square feet (1,000 square meters).
VALERY HACHE/AFP/AFP/Getty Images
The hope is that this eco-district will be a natural extension to the French Riviera, attracting new residents and adding to the appeal of Monaco.

Consequently, Monaco’s 38,000 residents are today squeezed into less than one square mile of land (2.02 square kilometers) – a territory smaller than New York’s Central Park.

And when an additional 40,000 people cross the borders from France and Italy each day to work, the problem only gets worse.

A new millionaire’s bay

As the people and money have poured in, more and more land has been reclaimed from the sea. Since the early 19th century, Monaco has gained an additional 100 acres, accounting for 20% of its territory.

Now construction has begun on a €2 billion ($2.3 billion) project to extend the natural contour of Monaco’s coastline a further 15 acres into the Mediterranean.

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Once complete in 2025, the new district, Portier Cove – near the legendary Monte Carlo Casino, which has appeared in three James Bond films – will house up to 1,000 residents in luxury apartments and villas.

Additional public spaces will include a hill and landscaped park, a seafront promenade and a little marina.

While the Government of Monaco is overseeing the project, private financers will front the construction cost and profit from the sale of real estate.

“Revenues for the private group through selling the apartments and houses will be more than €3.5 billion ($4.1 billion),” says Jean-Luc Nguyen, director of the government’s urban extension project.

Monaco is one of the most sought-after addresses in the world, and consequently the most expensive place to buy property.

For $1 million you can buy just 183 square feet (17 square meters) of prime property, according to the Knight Frank 2017 Wealth Report, compared to 280 square feet (26 square meters) in New York or 323 square feet (30 square meters) in London.

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Consequently, many famous residents have made Monaco home, including British Formula One driver Lewis Hamilton and Serbian tennis star Novak Djokovic.

An eco district for Monaco

Portier Cove is designed to fit snugly into the coastal landscape in order to conform to the flow of water near the coast.

“We wanted to give it a curved shape so that it is not an obstacle to the marine currents that oxygenate the sea,” says Denis Valode of Valode & Pistre, who is part of a team of architects working on Portier Cove.

DR: Valode & Pistre

Even so, building into the sea is complex and could potentially damage marine life.

But the key players involved in establishing this eco district are quick to underline its “highly ambitious target of sustainability and environmental protection.”

Prior to construction, protected plant species inhabiting the project area were relocated to nearby marine reserves, and special submarine screens were installed to insulate the site and minimize the impact on the environment.

According to Bouygues Travaux Publics, the French company leading the build, water quality is being rigorously monitored by a team of independent scientific experts throughout construction.

To compensate for the inevitable loss of natural habitats, Bouygues plans to install a wide variety of artificial habitats in vertical and horizontal ecological corridors.

According to Nguyen, this is what differentiates Monaco’s eco district from other offshore extension projects around the world.

“We haven’t seen any other projects with this kind of (environmental) reflection,” says Nguyen.

Bouygues Travaux Publics
The extension will be protected by a concrete seawall.

Currently, Bouygues is dredging silt from the area to lay bare the rocky seabed. The foundation will then be filled with quarried rocks to support a seawall consisting of 18 concrete-filled chambers called caissons. Each caisson is 85-foot (26-meters) tall and weighs approximately 10,000 tons.

Once this protective belt is secured in place, the final backfill of marine sand, extracted from northern Sicily, will be added.

The platform and infrastructure work should be complete by 2020 and the entire district open for business by 2025.

Making the artificial feel real

While it is an entirely artificial extension, Valode says the plan is to install a Mediterranean landscape of tall pines and other native vegetation to “give the feeling that the buildings are immersed in a natural environment.”

DR: Valode & Pistre
Valode hopes Portier Cove will not only be a place of residence, but a place of life.

Oversized balconies will shade the buildings from the sun in summer and help recover heat in winter. Added to this, 40% of the district’s energy needs will be provided by solar panels and pumps that use sea water to heat and cool buildings.

Each apartment will span over 4,300 square feet (400 square meters), while individual houses will measure approximately 11,000 square feet (1,000 square meters).

The topography of the extension will reflect how Monaco has developed, with the structures gradually increasing in height from low-lying villas to towering buildings – echoing the country’s evolution from a fisherman’s paradise to an attractive holiday resort, explains Valode.

“This is a project that is extremely contemporary, but draws its roots in the historical context,” he says.