The short answer: above 2,000 sq m of plot, or 2.0 hectares of layout, and only if the power supply authority says it is needed. Regulation 3.6 is short, conditional, and easy to leave out of an early layout.
Key takeaways
- The requirement applies on development or redevelopment of any land, building or premises.
- It is triggered only if the concerned power supply authority considers it necessary.
- Plot above 2,000 sq m: one single transformer sub-station of 5.0 m by 5.0 m, height not more than 5.0 m.
- Layout or sub-division of 2.0 hectares or more: a suitable site for a sub-station as required by the power supply company.
- It must sit at least 3.0 m from the main building.
- It should generally not affect side marginal distances, internal access width or recreational open space.
The two thresholds
Chapter 3, Regulation 3.6, UDCPR as updated 30 January 2025 sets the requirement in a two row table, and both rows are subject to the same precondition: if the requirement for the same is considered necessary by the concerned power supply authority.
Banded by size of the plot or layout
- Plot above 2,000 sq mOne single transformer sub-station of the size 5.0 m by 5.0 m, and height of not more than 5.0 m
- Layout or sub-division of a plot measuring 2.0 hectares or moreA suitable site for an electric sub-station, as required by the power supply company
Source: Chapter 3, Regulation 3.6, UDCPR as updated 30 January 2025
The difference between the two rows is worth noting. The first is a fixed 25 sq m footprint with a stated height. The second is open ended: the site is as required by the power supply company, so the area is settled outside this regulation.
What changes the answer
The proviso is where a layout can come unstuck late.
The sub-station must be constructed at least 3.0 m away from the main building, and in a manner that in general does not affect the required side marginal distances, the prescribed width of internal access, or the recreational open space.
Read that as three separate protections. It cannot be tucked into a side margin that the building needs, it cannot narrow an internal road below its required width, and it cannot be carved out of the 10 percent recreational open space.
Which means it needs its own ground. On a layout at the 2.0 hectare threshold, where the site area is settled by the power supply company rather than by this table, that is a piece of land whose size is not known from the code alone.
What it does not cost
The structure is outside the FSI calculation. Regulation 6.8(iv) excludes electric cabins of sub-stations and generator set areas, along with electric meter rooms as per requirements, treatment plant structures, rainwater harvesting pump rooms and garbage chutes with collection chambers.
That fits the pattern running through 6.8: what serves the building is free of FSI, and what serves the occupier is counted.
Separately, Chapter 3, Regulation 3.1.2, Distance of Site From Electric Lines* sets clearances from overhead electric supply lines, at 2.50 m vertical and 1.20 m horizontal for low and medium voltage lines, and 3.70 m vertical and 2.00 m horizontal for high voltage lines up to 33,000 V, with 0.3 m added for every further 33,000 V. Those are measured from maximum sag and maximum wind deflection rather than from a still day.
Related rule cards
- What counts as built up area, and what is excluded
- The 10 percent recreational open space
- Layout roads and minimum plot sizes
Where the filings come in
The register carries the figure both thresholds are keyed to. Land area is filed on essentially every published project, 46,636 of 46,654 outside Mumbai on ReraGenie's registry copy captured 11 August 2026, so whether a project is above 2,000 sq m or above 2.0 hectares can be answered for free from the filing.
Every filing at reragenie.com also carries the buildings and their floors, the promoter's extension history with the reasons given, and any complaints or litigation with case numbers.
ReraGenie's project analysis, Rs 2,999 for one project, reads the full filing and the documents behind it.
Source: Unified Development Control and Promotion Regulations for Maharashtra, UDCPR as updated 30 January 2025. Sanctioned under the Maharashtra Regional and Town Planning Act, 1966.
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