In the process of designing a red brick, riverside office building in Larvik, Norway, the architects needed to ensure consistent optimum energy balance for its users while at the same time creating an environmentally-friendly structure.

The 2,400 square-metre building combined 240 square metres of traditional windows with 220 square metres of large glass façades – facing all points of the compass. Part of the challenge, therefore, was to make best use of the building’s positioning. But, given the volume of glass that needed to be incorporated, the biggest challenge facing the architects was to ensure the minimisation of CO2 emissions and the maximisation of energy-efficiency.

The required outcome was achieved in the following ways:
• For the least-sunny north façade, choosing a three-pane IGU combination – two panes of Pilkington Optitherm™ SN and one pane of Pilkington Optifloat™ Clear – provided the best thermal solution.
• Solar control glass in the south, west and east-facing windows keeps the heat from the sunlight under control. By choosing Pilkington Suncool™ 66/33 as the outer pane in the IGU, it was possible to achieve a comfortable indoor climate for the users.
• The large glass aluminium-clad façades have the same combination, with Pilkington Suncool™ 66/33, Pilkington Optifloat™ Clear and Pilkington Optitherm™ SN, but using a thicker pane of Pilkington Optitherm™ SN. This combination has reduced the use of air conditioning and need for heating, providing a positive impact on the overall environment. Less energy is used, CO2 emissions are reduced and running costs are lower.

By choosing glass from the Pilkington glass range of neutral appearance products, a high solar and thermal performance can be achieved without sacrificing the natural appearance of glass in the façades.

Glass combinations

North façade:
TGUs made of: Pilkington Optitherm™ SN 6 mm - Argon 12 mm - Pilkington Optifloat™ Clear 4 mm - Argon 12 mm - Pilkington Optitherm™ SN 4 mm

South, west and east façades:
DGUs made of: Pilkington Suncool™ 66/33 6 mm - Argon 12 mm - Pilkington Optifloat™ Clear 4 mm - Argon 12 mm - Pilkington Optitherm™ SN 4 mm

Aluminium-clad façades:
TGUs made of: Pilkington Suncool™ 66/33 6 mm - Argon 12 mm - Pilkington Optifloat™ Clear 4 mm - Argon 12 mm - Pilkington Optitherm™ SN 6 mm

Note: Low emissivity glass Pilkington Optitherm™ SN is not manufactured any more. It has been replaced by Pilkington Optitherm™ S3.