Power Requirements for a 3-Storey Landed Home — Are You Underestimating Your Load?
- Hitomo Construction Singapore (2010) Pte Ltd
- Jul 24
- 3 min read
Updated: Sep 15
When rebuilding a 3-storey landed property in Singapore, many homeowners focus on aesthetics — layout, façade, lighting — but forget one thing: your electrical system is the backbone of comfort, safety, and functionality.
We’ve seen these issues too often:
“My induction cooker trips the DB box when I’m using the aircon.”
“The contractor said the load was enough — now we’re rewiring after TOP.”
Let’s break down what your home really needs and how to plan your power load correctly from Day 1.
Understanding Electrical Load: Why It Matters
Electrical load refers to the total power demand your home draws from the incoming supply. This is measured in kilowatts (kW) or amperes (A).
If your internal load exceeds what your system can handle, you may experience:
DB boxes tripping
Flickering lights
Underperforming appliances
Delays in PUB connection or inspection
💡 Rule of Thumb:
Every modern 3-storey home (with aircon, heater, kitchen appliances) will need 63A or 100A supply. Anything less can lead to long-term frustration.
Typical Loads in a 3-Storey Rebuild
Here’s a breakdown of typical loads in a 3-storey rebuild:
Appliance/System | Estimated Load (W) | Quantity | Subtotal (W) |
Inverter Aircon (per unit) | 800 – 1,200 | 7 | ~8,000 |
Instant Water Heater | 3,000 – 4,500 | 4 | ~15,000 |
Induction Cooker (2/3 zones) | 3,000 – 7,000 | 1 | ~5,000 |
Oven | 3,000 | 1 | 3,000 |
Washer + Dryer | 2,000 – 3,500 | 1 set | 3,000 |
Lighting & General Points | 4,000 – 6,000 | Entire | ~5,000 |
Smart Systems + Fridge | 1,500 – 2,000 | - | ~2,000 |
Total estimated load: 40,000 – 45,000W (40–45kW)
This translates to approximately 70–80 Amps.
📌 So why do many DBs come with only 63A (single phase) capacity?
Because older homes didn’t account for induction cooking, smart automation, or simultaneous usage of multiple high-power appliances.
Key Questions for Your Builder or M&E Engineer
When discussing your electrical system, ask your builder or M&E engineer the following:
What’s the incoming supply size (from PUB)?
Is a 100A single-phase or 3-phase 63A setup needed?
How many circuits are allocated for aircon, kitchen, and water heating?
Is the main distribution board (DB) rated appropriately?
Will future EV charging or solar feed-in be supported?
💡 Pro Tip:
Choose separate circuits for:
Aircon system
Induction cooker
Heater system
Lighting
General power outlets (3-pin sockets)
This prevents overload on shared circuits and improves energy efficiency.
Planning for EV Chargers, Smart Homes, and More
If you’re planning:
EV Charging Point (Type 2) → add 7.4kW (32A) load
Smart Home Hub → minimal load, but requires structured wiring
Solar System → work with a licensed EMA installer to plan the DB feedback loop
📌 Don’t skip this planning stage — upgrading your DB after completion can cost twice as much due to rewiring, hacking, and reinstatement.
Signs You May Be Underpowered
Be aware of these signs that indicate you might be underpowered:
Lights dim when the oven or AC turns on
Frequent DB trips under full load
Builder quotes that don’t list DB specs or load calculations
Electrician mentions a “standard setup” without tailored sizing
Why Hitomo’s M&E Process Prevents These Problems
At Hitomo Construction, we:
Size your DB based on actual appliance layout
Allow for future expansion (EV, solar, smart panels)
Label every DB circuit professionally for easy troubleshooting
Quick Checklist for Your Rebuild Power Plan
✅ Incoming supply: 63A / 100A / 3-phase?
✅ Separate circuits for high-load appliances?
✅ Induction cooker + water heater factored in?
✅ Future EV charger or solar power planned?
✅ SP meter and SP inspection ready?
Planning a Rebuild? Let’s Get the Power Right.
Your landed home deserves the comfort, safety, and efficiency of a properly engineered electrical system. Don’t settle for generic setups — let Hitomo help you future-proof from the inside out.
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