Exbury Egg

Materials World magazine
,
1 Jul 2014

Along Hampshire’s Beaulieu River lies the Exbury Egg – a floating home made entirely of wood. Melanie Rutherford speaks to Wendy Perring, Director of PAD studio architects, about the design and construction behind the unique creation.

How do you like your eggs? Poached, boiled, over-easy? For artist Stephen Turner, the answer is ‘floating on a river’. Since June 2013, Turner has been living inside his design studio, laboratory and home that is the Exbury Egg – a wooden egg-shaped structure sitting on the calm waters of the Beaulieu River in Hampshire.

To fulfil his vision of creating an inspirational workspace in which he could live and work for one year, while increasing public awareness of the threat of erosion to the New Forest coastline, Turner teamed up with project coordinator Spud Group and architect PAD studio, and together, the idea for the Exbury Egg was hatched.

Symbolising life and birth, the Egg’s design was inspired by the nesting birds laying their eggs in the long grass along the edge of the Beaulieu River. As such, the egg’s aesthetics were equally important to the designers as its structural integrity. Wendy Perring, Director at PAD studios, explains, ‘The Egg is designed to be a marker of the natural elements and will be eroded and marked by wind and tides. It was therefore essential that the material used would change with the passing season but also be flexible enough to form the complex shape, as well as have a small carbon footprint. After all, the ethos of the project was about creating something sustainable and low-energy.’ Initially the team considered using glass-reinforced plastic (GRP), but while this would have been easy to mould into the tricky egg shape, its less environmentally friendly credentials left timber as the obvious choice.

Plywood was chosen for the internal ribs that give the Egg its overall form, while local Douglas fir was used for the supporting ribs and internal framing. ‘This continues the age-old tradition of timber marine construction, which can be traced back many centuries on the Beaulieu River,’ says Perring. Two layers of planking form the Egg’s shell. ‘The inner layer is made from recycled cedar – including that from an old shed and a gate – and the outer layer is formed from western red cedar.’ Cedar was selected for its hardness, durability and ease of bending into small strips, while also being relatively knot-free and economical. ‘The only downside is that it was from Canada, not the UK,’ says Perring. ‘As supporters of the Grown in Britain initiative, ideally we’d like to have used home-grown timber throughout. Sadly, however, native cedar would have been too knotty for the external skin and chestnut would have been too soft. Douglas fir was another option for the planking, but in the end it came down to cost – and to the kindness of our suppliers, as much of the timber was donated and some was supplied to us at reduced rates.

‘The use of chemicals and nonorganic materials was kept to a minimum throughout construction,’ adds Perring. ‘We used a layer of glass epoxy between the two layers of timber in the shell to enable the surface to weather, which is similar technique to that used in boat technology – simply a form of waterproofing to ensure the Egg stays watertight.’

Energy use and carbon footprint were not only considered during the Egg’s construction, but right through to its end use. Inside the timber shell, Turner cooks from a small, two-burner cooker and in the living space, a charcoal-burning stove acts as a heat source. Light is provided by low-energy LED fittings, and portable photovoltaic panels are used to charge electrical items. While Turner has abundant access to water, he uses river water only for general domestic purposes, sourcing his drinking supply from a nearby standpipe in collapsible storage tanks. Meanwhile, blackwater waste is taken back to shore for disposal in a septic tank located in a nearby field.

The main challenges, says Perring, came in the five-month timeframe the team was given to build the Egg, as well as the budget, ‘which was very tight, given the complexity of the form and the time taken to achieve it. The structure itself also proved a challenge, as the curved form was hard to build – from smaller issues, such as the roof lights needing to be seamlessly integrated, right the way through to bigger engineering challenges, such as giving the shape added buoyancy to ensure that it did not roll off down the river.’

Cracking the challenge of getting the egg to rest safely and securely on the river, without the need for a traditional anchor, called for some innovative engineering. Water-filled buoyancy tanks made from recycled floating pontoon tanks provide ballast, and can be drained through an airtight plug to adjust the water/air ratio, allowing the Egg to rise and fall in the water.

You can’t make an omelette...

While the Exbury Egg does not require regular maintenance, it is not completely immune to the elements. Perring admits, ‘As with any timber boat immersed in water and subject to wind-driven rain, there have been a few leaks over the last few months, but these have been rectified by carefully filling some of the timber joints with further epoxy.’

Although the initial brief was for Turner to live and work inside the Exbury Egg for one year, ‘with a degree of protection throughout the winter months, we envisage that the Egg could last indefinitely,’ says Perring. ‘While the Egg was designed to erode on the surface, it is hoped that it will have a life well beyond the period of the artist’s residency. Our ideal would be that it is allowed to remain in situ and slowly rot away, like the shell of an abandoned boat – it would become a memory and retreat back to the earth. However, this poetic notion would have obvious detrimental environmental impacts as the timber erodes.’

Instead, the Exbury Egg will be removed from Beaulieu River after its time there as an exhibit is up and sold on. While this egg’s time on water remains uncertain, its fate will surely follow that of all wooden structures and return to its earthy roots.

For more information, contact Wendy Perring wendy@padstudio.co.uk or Mark Drury mark@spudgroup.org.uk