Step by step method to do daylight compliance using daylight simulation tools
A 7,200 m2
four story office building in Delhi is trying to achieve ECBC level
compliance. Building is oriented along east west axis. It has a rectangular layout (60 m x 30 m). Total
built up area is distributed evenly across all floors above grade. VLT of glazing in all orientations is 0.39.
Windows have light shelves and external shading devices with PF ≥ 0.4. Head height of fenestrations is
3.0 m. Length of glazing on the north and south facing façade is 45 meter and on the east façade, 25
Table 4-1 lists the minimum daylight area requirements for ECBC Buildings. Row 2 of the table specifies
that all ECBC Buildings other than resorts and shopping malls and, more than 3 stories above the
ground shall have a minimum of 40% of its floor area exposed to daylight in range of 100 – 2,000 lux
for at least 90% of the year.
This office building must then have at least 2,880 m2
(40% of 7,200 m2
) of floor area fulfilling the UDI
requirements. Across each floor plate, this area should be then 2,880/ 4 = 720 m2
Compliance with § 4.2.3 Daylight Requirements can be checked for through two approaches.
(a) Analysis through software
If the whole building performance approach is used, compliance for daylighting requirements can be
checked by analysing the façade and floor plate design in an analytical software approved by BEE (§
3.4). The image below, developed through an approved software, specifies the lux levels and time
period of a year during which lighting levels would be available. With this information, designers can
check if the required minimum area as per § 4.2.3 has the required daylight levels