How JK Bauen, Kleindienst are building Dubai's Floating Seahorse Villas
EXCLUSIVE PICTURES: Kleindienst reveals the prefab and marine engineering techniques behind the floating Palm Jumeirah homes
Few projects have captured the imagination of the international construction sector like The World islands, a man-made archipelago located 4km off the coast of Dubai. Following the project’s high-profile launch in 2003, the 300 small islets reclaimed from the sea to form a collection of private residential and resort islands promised a level of exclusivity that was largely unrivalled, even by Dubai’s standards.
Although interest in the megaproject lagged somewhat during the 2008 global financial crisis, Dubai-based real estate developer, Kleindienst Group, seized the opportunity to snap up six of the development’s islands – those known as Germany, the Floating Venice, Sweden, Switzerland, St Petersburg, and Main Europe.
The initial approach was to design something that looked stunning; the second step was to turn that into something realistic.
These islands comprise The Heart of Europe project, located off Dubai's Palm Jumeirah, and will become home to a mix of hotels, palaces, villas, chalets, vessels, and underwater living experiences. The latter will comprise “floating Seahorse Villas”, which will be built partly underwater and will mainly be located around the heart-shaped St Petersburg Island.
Sweden Island, which is home to Kleindienst Group’s show villa, will eventually house 10 four-storey, seven-bedroom “beach palaces”. Plots range in size from 1,400m² to 1,700m², with 1,254.7m² available for a single villa. Germany Island will also be home to 32 residential villas, and construction on both islands is already under way as part of the project’s first phase, which is set to be completed by the end of this year.
Kleindienst Group announced a doubling of its staff numbers last year in its effort to finish phase 1. The employee headcount of 878 in January 2018 increased to 1,672 by the end of December. Today, there is a workforce of more than 1,800.
Phase 1 of the development includes the completion of 78 Seahorse Villas, as the developer’s chairman, Josef Kleindienst, tells Construction Week following a site visit with the megaproject’s director of architectural design, Marco Bolzoni.
“The construction [of the Seahorse Villas] is handled by JK Bauen, a Kleindienst company with more than 1,800 employees living on the islands,” Kleindienst says.
“There are two editions: Signature and Bentley. They have the same structure and layout but different interior designs in terms of materials, colour, and furniture.”
The difference between a Seahorse Villa and a boat is its large underwater volume.
Bolzoni explains that the group’s first prototype of the unit was made completely from steel. “We spent countless hours putting the first prototype in the water. Those prototypes gave us a lot of experience and ideas about how to improve the design,” he says.
“We knew that we needed to start mass production but, before that, we needed to make sure the concept was perfect. The initial approach was to design something that looked stunning; the second step was to turn that into something realistic.”
Having previously worked on land-based projects, Bolzoni says he had to reassess his approach to weight when designing and building the sea-anchored structures. On the refined, second iteration of the Seahorse Villa’s design, he says he opted to use concrete for the submerged element of the structure.
“Concrete provides weight where you need it and does not require any maintenance, but only if it is done properly the first time, without any cold joints. Steel, on the other hand, requires periodic maintenance.”
He adds: “The difference between a Seahorse Villa and a boat is its large underwater volume. This means that we have a lot of water displacement, so we need weight to compensate for that, otherwise the Seahorse Villa would float higher than we want it to.”
With this in mind, perfecting the distribution of weight through ballast has been critical in ensuring the structures’ stability. “Imagine a boat: a boat is symmetrical with its ‘V’ shape. If you put it into the water, it will level itself,” he says.
We wanted to reflect the beauty of the water; to have the close relationship that a boat has with water, but with the luxury and the comfort of a villa.
“I normally think about weight resting on top of the foundation, but in this case, weight acts in a completely different way. I learnt that symmetry and regular shapes were needed for any structure that is in water.”
However, the Seahorse Villas are “completely asymmetrical in their weight distribution”, Bolzoni says. “A bathroom could be in one place, covered in marble, while the opposite corner of the villa could be relatively empty, offering very little weight to the overall structure.”
To address this, the Seahorse Villas have a “double bottom” – a 1m-high space between the floor and the concrete, which is used to distribute ballast using 30x30cm steel slabs, chosen because steel has the highest density of any easily available material.
The Seahorse Villa model was constructed entirely in-house, using prefabrication techniques in a bid to avoid cold joints in the concrete through the use of steel moulds. “We cast all the way up to above the water line. The covering slab can be done afterwards, because it is above the water line and we can have a cold joint there.”
Bolzoni continues: “We end up with a shell-and-core enclosed building that is ready to be put in the water. A lot of the fit-out is done when the building is in the water and it is quite complicated to ensure that things are level. There is a lot of adjustment.”
The final set up of the ballast is carried out when most of the house has been completed, he adds. “We need to have 90-95% of the weight in place. There is a lot of spreading and positioning.”
Bolzoni says the group opted to use glass-reinforced plastic (GRP) cladding because of its flexibility, which makes it possible to achieve the curves of the Seahorse Villas’ structure. The aim is for the villas to have a “floating platform that curves to create a roof”.
By adding ocean ownership through the title deed, however, it will significantly increase the value of each villa.
“We wanted to reflect the beauty of the water; to have the close relationship that a boat has with water, but with the luxury and the comfort of a villa.”
Bolzoni says that a pontoon attached to each Seahorse Villa will also be used to run all of the structure’s main infrastructure, such as fresh water, power, and data cables. As a result, all connections will be hidden, but will be raised above the water to “ensure longevity” and so that repairs can be carried out easily.
Kleindienst adds that, “for the first time in the world”, a dual licensing structure has been applied to the Seahorse Villas, “providing the highest value-creation and investor protection possible through the classification of the floating Seahorse Villas as vessels and villas”.
“The structure can therefore be moved at any time because of its vessel title, and its real estate title protects the sea area,” he explains.
“In The Heart of Europe specifically, the [Seahorse Villas] will be known only as villas. By adding ocean ownership through the title deed, however, it will significantly increase the value of each villa. It will allow owners to treat their property in the same way as an onshore one, and the plot on which a property sits is usually valued between 20% and 50% of the total asset value.”
Bolzoni further explains the specific challenges of building a project of this scale offshore. “With time, we understood that building here, we needed to be as self-sufficient as possible and not rely too heavily on independent consultants,” he says, adding: “Of course, they are a great resource when needed.
“We have JK Bauen that is based here, and our own GRP team, for example. We would rather build our own team than call in a specialist. Of course, there are certain things that we cannot do but, over time, we have begun to specialise.”
The structure can therefore be moved at any time because of its vessel title, and its real estate title protects the sea area.
Given the Seahorse Villas’ underwater views, Bolzoni says that ensuring a healthy seascape surrounding the properties is important. “Our villas are not facing a garden, but an underwater world,” he says. “We do not have gardeners, but a diving team and a marine biologist instead, who take care of everything outside of the Seahorse Villas.”
Kleindienst Group has a programme on site to develop new colonies of naturally occurring coral through a process called fragmentation. Corals are collected from other projects along the shore, as Bolzoni explains.
“It could be from a new marina that is being built, or a new project that requires digging or dredging in areas that have coral. Our team retrieves as much living coral as possible and, through fragmentation, the corals can be propagated in a controlled environment. Some of the bigger pieces are used for further fragmentation, or they are used in the coral gardens that are connected to the Seahorse Villas.”
With time, we understood that building here, we needed to be as self-sufficient as possible and not rely too heavily on independent consultants.
The unique and complex requirements of the project mean that in order to achieve The Heart of Europe’s first phase completion deadline of late 2019, the developer will need to hire an additional “250 staff per month for the first six months of 2019”, says Kleindienst. This will also support the completion of phases 2 and 3.
“[Switzerland Island] and some of the hotels on Main Europe, which is the big island, will be the last to be handed over,” Bolzoni concludes.
“This is where most of the facilities are, and the bigger buildings take the most time to construct.”