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Monaco Land Extension Project Reaches Milestone, Caissons Belt Completed / Bouygues Travaux

Monaco Land Extension Project Reaches Milestone, Caissons Belt Completed

The tax haven has a luxury housing crisis – it doesn’t have enough land for the 2,700 multimillionaires forecast to settle there over the next decade

When an area has developed every square foot of land, the next step is usually to start building upward, à la New York City. But rather than squeeze in new skyscrapers, Monaco has always taken a different approach. The city-state on the French Riviera packs a population of over 38,000 into 500 acres (just under one square mile), and its real estate is the most expensive in the world, with buyers paying an average of $4,536 per square foot, according to Savills. So to increase the available land space, the principality is once again expanding into the Mediterranean.

The new district, called Portier Cove, will add an additional 15 acres and is set to be completed in 2025. The project, which is owned by the state, is helmed by civil engineering firm Bouygues Travaux Publics, with Valode & Pistre Architectes in charge of the coordination of the design firms and overall plan. Other firms involved include Renzo Piano Building Workshop, who will be designing a residential building, landscape architect Michel Desvigne, and Monaco-based architects Alexandre Giraldi and Patrick Raymond.

This is not the first time that Monaco has reclaimed land from the sea. The principality first began expanding in 1880, and Prince Rainier, known as the “builder prince,” increased the size of Monaco by 20 percent during the 1960s and ’70s. The new $2.3 billion undertaking will create nearly 650,000 square feet of residential and commercial space to accommodate up to 1,000 residents. The district will also boast a landscaped park, a marina with 30 berths, and a central public square. The Grimaldi Forum, a conference and cultural center, will be expanded into the new land, allowing for a 50 percent increase in capacity.


An aerial rendering provides a view into the new developments planned for Monaco's $2.3 billion expansion into the Mediterranean Sea.

To build the extension, Bouygues Travaux began by dredging the area so that 18 caissons (a watertight structure that's typically used to work on the foundations of water-based structures) could be added. The band of 10,000-ton caissons will be connected to form a seawall surrounding the reclaimed land. Over 21 million cubic feet of sea sand dredged from north of Sicily will be used to fill in the reclaimed land. The maritime infrastructure is expected to be completed by the second quarter of 2020. “The techniques we are using are old techniques, but they are pushed to the limits of what we are used to doing,” says Christophe Hirsinger, director of Bouygues Travaux Publics.

Just one year after the arrival of the first caisson, the Monaco Land Extension Project reached another amazing milestone last week – the 17th caisson was successfully immersed, completing the ‘belt’ that will form a new coastline in Monaco.

The structure, erected during the last 12 months, is 500 meters long and rests at a depth of 20 meters on a specially designed underwater hill.

The next step is backfilling of the internal surface with 400.000m³ of sand. By the end of 2019, the Principality of Monaco will see its area increased by 6 hectares.

This new piece of Monegasque territory will host a luxury eco-district comprising 150 upscale apartments, an underground car park, a coastal promenade, a green park, public facilities, an extension of the Grimaldi Forum and an animation port.

The first delivery of the buildings is set to begin from 2022 and all the works should be completed in 2025.

See Monaco Land Extension Project Reaches Milestone, Caissons Belt Completed (Dredging Today, Julyn24, 2019)

See Monaco’s $2.3 Billion Expansion Into the Mediterranean Sea (Architectural Digest, July 9, 2018)

See also Monaco builds into the Med to house new throng of super-rich (Guardian, Sun 19 Nov 2017)