The new Swords office development is being built at the established Airside Business Park, close to Dublin International Airport. This building is a speculative office, the first of a proposed new phase of four buildings. It is to be the largest in the phase, at 5,234m 2 gross, comprising an undercroft and three floors above.
The design of the approach to the building, particularly, with its oversailing grid canopy, draws attention to the freestanding columns that support both canopy and the external shading of the layered facade. The architect, RKD Architects, was made aware of the availability of oval hollow sections (OHSs) by engineer Thomas Garland & Partners, which had used them at government offices in Waterford. Architect Vicki Landy feels that for this project 'they work well with the whole language of the buildings' The external shading system is supported on 500mm x250 mm ovals, with their curvature echoing the shading's blades and perhaps linking to the theme of aircraft nearby. This size of oval is used too in the atrium steelwork, though 300mm x 150mm ovals are used for the internal feature staircase.
(The building is not yet tenanted and the interior has only been taken as far as shell and core fit-out. ) As Garland's Kevin Rudden points out, the ovals are stronger in the direction needed while being relatively light seen from the front of the building - the aim was to make the brise soleil predominant rather than its supporting steelwork. The bolted connections were straightforward; as Rudden says, 'they look a lot more difficult than they actually are'.
External ovals are galvanised, internal ones are painted.
All these ovals are part of the Celsius range of structural hollow sections, along with the more familiar square, rectangular and circular sections. Ovals are rolled by Corus Tubes at Hartlepool and Corby, electrically welded and hot finished. The normal range of finishes and of welded and bolted connections used for other hollow sections can be used for ovals too.
For each size of oval, three-to-five differing wall thicknesses are available, giving varying structural properties.
So there is a better chance that where required aesthetically, the same external-sized ovals can be used consistently where loads differ, while maintaining structural efficiency.
Ovals are not a big step from using other hollow sections.
That's the point. They are just as straightforward to use. But for the designer the palette is enlarged.
Contact Corus Tubes at www. corustubes. com, email corustubes. s-c@corusgroup. com, tel 01536 402121