Hendriks precon smart formwork technology for floating villasOne-piece concrete structure keeps feet dry

As a country, 60% of whose landmass is below water level, the Netherlands is inextricably linked to water. Moreover, over the last several decades, water has become a desirable living location. The construction development company Zederik Bouw/Damsteegt Waterwerken anticipates this demand by specialising in the on-site construction of floating homes. Hendriks precon, at the request of Zederik Bouw, developed special formwork for these floating water homes.

Living on Water

Living on water is an exuberant experience every day. Comfort, space and experiencing the water effortlessly merge in the 27 luxurious floating villas that are currently being built in Lent near Nijmegen. The architecturally designed floating homes are moored to shared entrance piers with lots of open space between them to guarantee all homes have a broad view of the Lentse Plas – a man-made lake near the village of Lent.

Zederik Bouw’s building system is smart and sustainable. A high insulation value is combined with a level of energy consumption that is much lower than current standards. Solar panels and an innovative heat pump are standard features. If desired, the homes can be equipped with a heat exchanger that extracts energy from the water on which the home floats. This makes it possible for the tap water to be heated in an environmentally friendly way at no cost.

Floating Villas

The floating villas along the Lentse Plas are built by Zederik Bouw. The homes have a surface area of between 160 – 180 m2 and are equipped with inside storage space and a protected terrace. The sleeping area in the basement contains four bedrooms and a spacious bathroom. We are speaking with Arnaud de Bruin of Zederik Bouw about the design of the villas. ‘In the past, the floating hulls for various projects were made of a composite material, but for this project we specifically chose concrete. Hendriks precon had submitted a proposal for this in the past and this now came in handy.’

He continues: ‘We often work with prefab elements for this type of project that are supplied to the site and processed there. But in this case the villas are built near a recreational lake and it is not possible to have the hulls delivered as prefab elements. This is why we pour the floating hulls on-site and then hoist them into the water.’

One-Piece Construction

Hendriks precon supplied a steel formwork set consisting of 9 elements for pouring the floating hulls. ‘These elements are assembled onshore on a concrete slab to create the formwork. The formwork is used to pour the walls and the floor of the floating hull centreless and all at once. The outer formwork is equipped with braces and the inside formwork is supported by transverse and longitudinal beams that on the inside run along the width and length, respectively, of the floating hull. The formwork is assembled, the rebar is installed and the concrete is poured in three days. Because everything is poured all at once, there are no connecting parts or construction joints and there is therefore no possibility of leaks.’

The walls of the concrete floating hull are approx 1.90 metres high. ‘When we lower the hull into the water, we stay approximately 50 cm above water. The wood structure is then built on top of this. The bedrooms and the bathroom are built in the floating hull itself, in other words below water level.’