BELOW THE WATERLINE - SUSTAINABLITY & RATIONALISING COMPLEXITY WITH 3D DESIGN

Design Development - Sustainable Design

The concept design has developed with a strong base in sustainability and the employment of passive design to create a building not only reflective of the clean energy it represents, but also one that minimises its impact on the environment, both through construction and  also during its lifetime.

The design is also shaped to create an environment suitable for its use by educators, exhibitors, artists and engineers whilst creating a pleasant environment for visitors to enjoy.

Solar influences will be managed to control high solar gain at midday and late afternoon in summer whilst providing potential solar gain in the early morning at other cooler times of the year.

The alignment of the shells to offer protection from the prevailing wind and wave action is close to coincident with the natural alignment to manage solar control so there is a synergy between the two aspects reinforcing the design layout. The form also allows natural light to penetrate into the deeper spaces as well as creating differing patterns, reflections and subtle light qualities onto the curved walls.

The tall core void area, or atrium, will create a natural vertical air shaft and heat stack to aid air movement through the building whilst low pressure displacement ventilation will trickle temperate air through the gallery spaces. Air could be drawn through ground plenums utilising the constant ground/sea temperature range to reduce seasonal fluctuations in temperature and energy load.

In further tempering the environment the structure will be exposed to provide a thermal mass sink to manage temperature fluctuations and balance temperature exchange through the air and fabric. This will be achieved by exposing the soffits of the concrete floor slabs throughout the building as well as wall surfaces where appropriate whilst taking into account the need to achieve the appropriate level of thermal insulation.

Where artificial lighting is required low energy lamps will be used to reduce the energy load.

The intention and target for the building is to be ‘self-sufficient’ in that it is not connected with the network and where energy used by the building is captured from renewable sources or transferred through recycling waste energy as a by-product of the Turbine Action.

The design includes photo-voltaic panels on the roof and walls of the Turbine Gallery.

Other areas of the roof will provide a natural ecological base for wildlife to inhabit forming an educational ‘roof garden’ for visitors whilst providing key views from the centre towards the landscape, sea and lagoon.

Rain water will be harvested and grey water recycled with water saving fittings to reduce water consumption. Our calculations indicate that there will be more than sufficient capture to provide this facility.

It is proposed to use ‘water-less’ urinals and also composting toilets, which whilst at the early stages of technical development, would provide an improved sustainable platform.

Materials

Due to the exposed marine environment and the consequent need to provide a robust outer skin to the building, concrete is proposed as the structural frame and main building element for the shells. The inherent quality of concrete and the construction process lends itself to manufacturing the complex shell forms and the concept design explores the possibilities that concrete offers. Through design development the shells could be manufactured locally using repetitive moulds and the tough outer skin can be produced with textured form work to create the rough texture reflecting the oyster theme.

However to reduce the environmental impact of concrete where carbon dioxide is released during the cementitious process, it is proposed to add ground granulated blast furnace slag (GGBS) to the cement to reduce the embedded carbon content. This blast furnace slag should be available locally as a by-product of the steel production in Port Talbot.

Other blending substitutes can also be added to increase the recycled content of the concrete and by utilising the proposed prefabrication process locally the carbon footprint of the construction process should be further reduced.

The concrete frame will also provide thermal mass where exposed, assisting the operational management of the Centre and its environmental comfort.

In contrast to the robust and textured outer weather protective skin, the internal walls will be a smooth plaster finish, with an almost pearlescent finish, reminiscent of the natural make-up of oyster shells.  The internal make-up of the shells will be adaptable to suit the changing needs of the Visitor Centre and will be easily maintained. The space between the outer and inner sandwich skins will contain service voids to service the galleries and provide a high level of building insulation.

The structural soffit of the roof over the upper gallery will be of timber construction providing a natural feel and sense of warmth. This will add an interesting contrast to the white internal walls and textured outer skins.

External glazing will be in the main clear with solar performance and heat retaining qualities but with the opportunity of integrating commissioned art work comprising panels of coloured or decorative glazing produced by local artists.

The resultant design will result in an exciting, robust and elegant interior with an adaptable gallery space to support changing exhibits and events, whilst creating a unique and memorable place.

The principle access for visitors to the Off-Shore Visitor Centre will be by electric bus running from the western landfall, dropping and collecting visitors by the entrance to the Centre.  Access into the building and throughout the building will be step free providing easy access for people of all abilities.


Rationalising Complexity & 3D Design Development

The initial concept design makes reference to oysters and the influences about the site. The design arranges shells to create a defensive robust outer layer made with several interacting walls where the alignment of the walls is organised to provide shelter from the prevailing south westerly wind and wave action but arranged to permit key views out from the centre.

This concept configuration has been developed through many iterations. Studio models and sketch diagrams have informed the development of these shapes to assist in the understanding of the three dimensional qualities of the building and to achieve a specific form driven by the key aspects, views and influences.

The concept and ideas expressed with this design offer an exciting form and complex building. The inherent nature of concrete provides a great base to create these forms as opposed to other elemental ‘stick’ construction techniques but whilst exploring the possibilities that concrete offers a design methodology was required to manage the process such that the design could be explained with simple mathematical formulae to provide a base to develop the technical design.

The key design stage takes these concept ideas and free form models and seeks to reduce the complexity and to rationalise the design to make construction more efficient, whilst not diluting the concept and three dimensional expression of the building.

Learning from the Sydney Opera House the rationale of seeking a geometric form from which the shells can be calculated and engineered was investigated. 3d wire frames were developed over the sketch design to find common master forms from which the skins of the shells could be described.

This process resulted in various options with further detailed analysis and rationalisation to develop simple spheres that comprised the majority of the shell shapes. From these studies two principle geometric shapes prevailed – a sphere and a cone. Whilst it was desirable to achieve one common form the deep circulation and light reflecting atrium of the concept design fell outside the characteristic of spheres so a cone was adapted to maintain the qualities of the design concept.

From this 3d design analysis simple shapes and, in consequence, simple mathematical models will form the basis of the next stage of technical design.

This analysis also provided a basis to determine a matrix whereby repetitive moulds can be calculated to enable the shells to be pre-cast in sections. This not only brings efficiency in using repeat moulds in the pre-fabrication process but also to achieve the optimum form the that can be readily transported along the lagoon walls and erected effectively as part of the construction process.

Visitor Centre Project Team

Juice Architects    Visitor Centre Architect & Designer
Evolve    Visitor Centre Structural Engineer
LDA Tidal Lagoon Masterplaner and Public Realm
Atkins Global       Tidal Lagoon Design Engineering
Costain     Tidal Lagoon Engineering Solutions Provider

Tidal Lagoon Team and Partners

http://www.tidallagoonswanseabay.com/