The new Giant’s Causeway visitor centre has opened in Antrim, Northern Ireland to critical acclaim.
Located on a prestigious and protected World Heritage Site, the entire design and construction team, from internationally acclaimed architects Heneghan Peng to mechanical and electrical engineering consultants Bennett Robertson, had to work within restrictive guidelines.
Every summer, thousands of visitors walk upon the 40,000 interlocking, polygonal columns of layered basalt of the Giant's Causeway. Formed by the cooling and shrinking of successive lava flows resulting from intense volcanic and geological activity over 60 million years ago, this natural tourist attraction is a UNESCO World Heritage Site.
The new 1,800 square metre visitor centre cost £18.5 million, took 18 months to complete, and has achieved a certificated BREEAM assessment rating of 'Excellent' under the world's leading design and assessment method, which sets the standard for best practice in sustainable building design, construction and operation.
To achieve this level of environmental performance, the centre not only utilises materials such as recycled aggregates within its construction but also includes innovative underground systems for its heating and cooling.
Planning restrictions precluded the use of traditional boilers and chillers, so heating and cooling coils within bespoke air handling units (AHUs) tailored specifically for each use had to be selected to operate in conjunction with the services supplied from the ground-source heat pump system and the earth pipe ground coupled heat exchanger.
The location of the fresh air intake, together with the limited space in the plant room, also meant precise co-ordination was needed to provide some degree of flexibility for the installation and associated services.
Two AHUs with a duty of 3.6 cubic metres per second are located in the exhibition area and the retail and café areas, and one intake plenum with a duty of 7.2 cubic metres per second also serves the exhibition and retail areas. Another AHU with a duty of 1.4 cubic metres per second serves the kitchen area. The fully welded, galvanised framework of the units creates a robust and highly durable solution, in which airflow ranges from approximately 0.3 to 35 cubic metres per second - and even higher by considered design - to provide a quality environment for visitors.
The defining feature of the visitor centre, however, is the material from which it has been created. The stacked basalt columns that rise out of the ground to form the façade were quarried locally at Kilrea from the same lava flows that formed the nearby Causeway.
As a large part of the energy efficient centre is underground, light was introduced into the interior by way of glass panels between the polished basalt columns. The accessible grassed roof area, which blends seamlessly into the environment, gives a 360-degree view of the Causeway coastline.
Walks and trails around the site have also been upgraded and access to the Causeway Stones via the footpath has been preserved.