Spectacular double facade construction saves energy in Nokias new head office

The new head office premises of the Nokia group, called Nokia House, comprises two buildings with an atrium-like meeting area covered by a huge glass roof. Both buildings are surrounded by a double facade construction which consists of a normal concrete wall combined with a glass structure some 70 centimetres outside the actual wall.
"The main purpose of the double wall structure is to improve the working environment in the building. The air cushion reduces the need for heating and cooling, which in turn leads to improved air quality indoors. The employees
may open the windows and ventilate the office rooms even during rain and frost", says Pekka Helin, the project's main architect at Helin & Siitonen Oy.
As a result of the insulating and temperature compensating function of the Ecofacade, it was possible to reduce the number of heating and cooling units in the building. Thereby, energy costs have been cut, as have maintainance costs for the buildings.
"Ecofacade works like a 'rain coat'. It keeps the temperature at a steady level and prevents wind and moisture prematurely wearing out the buildings and the inner facade. In addition, it opens up new opportunities for architects to create interesting and futuristic constructions", says Pekka Helin.

Tailor-made tubes
The metal structure of the Ecofacade is made of hollow, stainless steel tubes (AISI 316) supplied by the Finnish, Stala Oy. The tubes are tailor-made, 90 x 45 mm in profile with a wall thickness of 3 mm, and a length of 7196 mm.
"The dimensions of the tubes were optimized for maximum strength and minimal deformations as a result of variations in temperature. In a structure like this, the demands made on precision of measurement are very high and tolerances for execution very small. The glass and stainless steel components must fit together perfectly", says Jan Christiansen, managing director of Stala Oy in Lahti, Finland.
According to architect Pekka Helin there were several
reasons for choosing stainless steel tubes for the new facade structure.
"The high strength of stainless steel made it possible to use hollow sections small enough to refelect the light and open impression of the building. Also, stainless steel is an elegant material which has a more lively surface than, for example, anodised or clad aluminium", he says.

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Facts and figures:
Number of building units: 2
Inauguration: November 1996 and April 1997
Total building area: 38 600 m2
Total building volume: 194 000 m3
Number of employees: 1 000
Number of parking spaces: 700

For further information, please contact:
Stala Oy
Jan Christiansen or Jussi Aro
Taivalkatu 7
FIN-151 70 Lahti, Finland
Tel: +358 - 3 882 110
Fax: +358 - 3 882 1114