Standards and Recommendations - Road Lighting: Fundamentals, Technology and Application - page 252

Table 17.7 Maximum lumen
per square metre for sports,
area and architectural lighting
installations depending on the
lighting zone. Values
converted from lumen/ft 2 to
lumen/m 2 . (IDA-IES 2011 )

lumtot /m 2
(lumen/m 2 )

Lighting zone

LZ0 5.4

LZ1 13

LZ2 27

LZ3 54

LZ4 81

17.4.2.1 Limit of Luminous Flux

The maximum luminous flux of the total installation per area of the installation,
lum,tot /m 2 is dependent on the actual lighting zone as given in Table 17.7 .
The ordinance allows for some specific genres of area and architectural installa-
tions, such as facade and outdoor sales-lot lighting, to have some additional luminous
flux in addition to the values given in Table 17.7 .

17.4.2.2 Limit of BUG Ratings

To limit back-light, up-light and glare, the BUG rating of the luminaires is used as
the limiting parameter. The lower the BUG number, the better the limitation. The
degree of limitation of back-light (B) and glare (G) is dependent on the distance of
the property from the lighting installation: the smaller this distance, the higher the
degree of limitation needed. Table 17.8 gives the limiting ratings. As can be seen
from the table, the upward component (U) must always be zero.

17.4.2.3 Limit of Lighting on Surfaces of Virtual Enclosure

As an alternative to employing the BUG method, the ordinance gives the method of
limiting the light falling on the surfaces of a virtual enclosure surrounding the area to
be lighted. The associated limiting parameters (virtual flux ratio and virtual vertical

Table 17.8 Maximum allowable BUG ratings of luminaires according to lighting zone and distance
from property. Distance (dist) is given in terms of mounting height, h . (IDA-IES 2011 )
BUG

Lighting zone dist > 2h dist < 2h dist < 1h dist < 0.5 h

LZ0 100 100 000 000

LZ1 301 200 100 000

LZ2 402 301 200 000

LZ3 503 401 301 100

LZ4 504 402 301 201