GREEN TIPS
4
Green design for shopping malls and shop spaces
4.3
Natural lighting in shopping malls and shop spaces
Glare is another problem that requires special attention. Direct sunlight creates glare. Glare along a mall corridor where
people would not stand for long is sometimes tolerable though not desirable. However, glare in the atrium, seating areas
or within a tenant’s shop area must be totally avoided. Since the sun’s path is totally predictable, the problem can easily
be resolved by using suitably positioned shading devices. As discussed above, adjustable shading devices provide better
results as they can be pulled away when the day is gloomy to allow more daylight in. However, such devices are usually
more expensive than fixed types. They also require careful control by the mall management and regular maintenance for
them to function properly.
Relationship between different finishes and quality of daylighting:
Classic approach to design for daylighting – reflected daylight
A classic approach to design for daylighting is to rely totally on reflected daylight and minimise direct linkage
between the skylight and the interiors.
Sometimes reflectors doubling as shading devices are placed underneath skylights. Deep mullions,
ceiling and wall finishing of light and matt surface help diffuse the daylight indoors and become the light
source themselves. Moreover, their surfaces can decorate with reliefs of different shapes, sizes and depths
to produce interesting visual effects through light and shade.
Figure 86 North facing skylight and
shading devices in ifc mall, Central
Figure 87 Effect of natural lighting at the
atrium in ifc mall, Central
(Source: Photographer, William Furniss)
C
Light colour on a matt or rough
surface provides diffused
reflection. Sunlight is reflected in
all directions creating a diffused
effect. Light matt finishing next
to a daylight source will appear
white instead of black and dark,
and the tempered contrast is
more comfortable to the eye.
Since light is diffused, it provides
a better colour rendering in the
interior with a more average
luminance level.
A
Dark colour provides little
reflection. If dark colour finishing
materials are placed next to
windows or skylights, a large
contrast in brightness between
the light source (the glazing area)
and the surroundings will result.
Visually, all surfaces except the
light source become dark and
black in colour and become very
uncomfortable to look at. Unless
there are special effects to be
achieved through the brightness
contrast, dark colour finishing
should be avoided near the
sources of daylight.
B
Glossy finishing as in mirror finish
stainless steel, glass cladding and
polished granite, etc. provides
good reflection. However, since
the surface is glossy, the reflection
is directional, meaning you only
see the reflection of the light
source at the correct angle, and,
when you do, it is almost as bright
as the source. Glossy materials
are not very useful in enhancing
the daylighting qualities indoors,
as they simply repeat the source
through direct reflection without
diffusing and tempering the light.
Hong Kong Green Building Council 111
