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The architect and interior designers worked closely
with the developer and tenant, and the electrical
consultants, to develop a lighting scheme for the
building. The primary constraints were budget and
the sustainability requirements.The building, which
ultimately achieved a 6 Star As Built rating, was
initially briefed to achieve 5 Stars under the Green
Building Council’s Office Design Rating Tool.
A great deal of attention was given to using
natural daylight wherever possible.The office areas
are all open-plan and have direct views to the out-
side. An atrium cuts right through the building and
its shape was emphasised by including lighting to
the perimeter and feature structural steel elements.
Additional daylight was brought to the centre of the
atrium via large skylights.
The architectural concept called for large areas
of glass and, according to Arup façade engineer
John Abbott, the glass facade was studied in some
detail using energy and lighting simulations and
drawing on the experience of colleagues with other
highly transparent buildings in similar climates.The
solution was to use double skin facades on the
northeastern and northwestern elevations, which
were most vulnerable to solar gain. These facades
have an outer skin of clear glass, spaced 700 mm
outside the main facade.The latter is double glazed
for thermal control and forms the building envelope.
Automatically-controlled blinds between the
inner and outer skins track the sun as it moves
across the building.When the blinds are open, the
floor-to-ceiling glazing allows good day lighting of
the space, with a daylight modelling study indicat-
ing that 37.5% of the usable area has a daylight
illuminance of higher than 250 lux. The majority of
the lighting in the office space was specified as
T5 fluorescent lamps with high frequency ballasts.
These have proven to be as efficient as LEDs and
have guaranteed life spans of up to 18 000 hours.
Since a primary focus of the lighting design
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