| Primary value | 1.0 W / sqft (range 0.8 – 1.2 W/sqft of built-up area) |
| Applies to | Apartment, bungalow and group housing electrical sizing · Pre-tender estimation of total connected load · Service connection sizing and DG sizing |
| Exceptions | Compact apartment (< 600 sqft) → 0.8 W/sqft |
| Standard apartment (600 – 1500 sqft) → 1.0 W/sqft | |
| Premium apartment / villa (> 1500 sqft) → 1.2 – 1.5 W/sqft | |
| All-AC household → 1.5 – 2.0 W/sqft | |
| Diversity factor (apartment block) → 0.5 – 0.6 | |
| Per-flat connected load (typical) → 5 – 8 kW | |
| Measured as | Sum of nameplate ratings of all loads (lights, fans, AC, geyser, kitchen, sockets) ÷ built-up area in sqft. Apply diversity factor at the building level for service-connection sizing. |
| Source | NBC 2016 — Part 8, Section 2, Cl. 5.2 📚 Cross-referenced |
16 related items across IS codes, knowledge articles, design rules, maps and tools
Connected-load per sqft is the first input every electrical consultant uses to size the service connection, transformer and DG set. 1 W/sqft ≈ 100 W per 10 × 10 ft room — covers 2 fans, lights and one socket per room. Going below this implies under-loaded design that will trip on day-1 of an AC install.
MEP consultants budget 1.0 – 1.2 W/sqft for residential and apply a diversity factor of 0.5 – 0.6 at the substation level — so a 200-flat building with 1000 sqft each lands at 200 × 1000 × 1.0 × 0.55 ≈ 110 kW connected demand, sized as a 200 kVA transformer.