Section 29(12)(a) in Tamil Nadu Electricity Regulatory Commission Tamil Nadu Electricity Distribution Code
(a)an electrical room with RCC roof having clear floor area 6 metres W 4 metres with a vertical clearance of 2.75 metres with locking facility, exhaust fans and ad equate size of cable duct, shall be provided at the ground floor within the consumer premises of storied buildings nearer to the main entrance for installing floor mounted distribution transformer and associated switchgear or