Architectural Record 2015-02

128
ARCHITECTURAL RECORD FEBRUARY 2015 LIGHTING DAYLIGHTING
stories—with 623 apartments. The
towers rise from a shared three-story
podium that includes a pool, restaurants,
and a shopping center. The
reinforced-concrete frame, enclosed by
a glass curtain wall, is shrouded by
horizontal planters and climbing
plants. Tall for the area, One Central
Park’s height matches a brutalist university
tower (designed by Michael
Dysart in 1964) directly across the road.
In urban terms, the pair serve as a
gateway to the city center, since the
road it straddles is the main access to
Sydney from the west. But the placement
also meant that Central Park’s
tallest structure would sit on the
development’s northern boundary.
This move was diplomatic, since it
will keep shadows off adjacent neighborhoods.
But it was also problematic,
because One Central Park would cast
a major shadow over its own site—in
particular the 69,000-square-foot public
garden fundamental to Quek’s vision.
The solution was the 148-foot cantilever
and its heliostat—an apparatus with a
movable mirror that reflects sunlight.
The idea was to bounce sunlight into
the tower’s own shadow, the garden,
and into the shopping center’s atrium
through a water-topped glass roof.
No one was sure it would work, or
even really what working might mean.
The structure alone—Australia’s largest
residential cantilever—weighs 120 tons
and is supported by a huge triangular
truss (which also supports a terrace).
It was the cantilever, as much as
the heliostat, that had people worried.
Nothing similar had been attempted
on this scale. Where heliostats had
been deployed, it was mostly small
solar energy installations. A large,
multi-mirror heliostat for the enhancement
of public pleasure was a whole
new deal, bringing aesthetic issues into
play alongside the strictly technical.
In fact, there are two sets of mirrors:
one facing down from the taller building
and one facing up from the shorter
edifice. The upper, 320-mirror array
that is visible to passersby, appears to
flutter. This is especially so after dark
when, in an installation by light artist
SUN FOLLOWERS The heliostat includes 40
computer-controlled sun-tracking mirrors on
the shorter tower’s roof; these bounce light off
fixed reflectors on the cantilever.
PHOTOGRAPHY: © JOHN GOLLINGS