Many homeowners focus on fixture placement and appliance points, while the electrical capacity of the flat often goes unnoticed. Every unit is built with a defined electrical allowance, and that limit shapes what the household can safely run at the same time. Older blocks were designed for lower electrical demand, while newer BTO flats come with higher capacity because modern homes rely on heavier kitchen equipment, multiple air-conditioning units, and high-demand fixtures. When renovation plans include an induction hob, a built-in oven, or additional air-con points, the electrician usually has to reassess the load. This requirement is not a matter of convenience; HDB and SP Group require the supply to remain within safe limits to prevent overheating, tripping, and wiring strain.
An HDB flat can only pull a set amount of power at any moment, and that limit is what electricians refer to as the electrical load. The flat draws its allowance from the block’s distribution network, and the main circuit breaker is the control point that caps the amount of current the unit is permitted to take in. Its rating dictates how much current the home can pull at once before protection mechanisms step in. The wiring inside the flat also plays a part; older circuits were built for lighter usage, and may not tolerate the heat produced when multiple high-demand appliances operate at the same time. Load isn’t simply a question of how many items are plugged in, but how much current they draw at the same time. An induction hob, air-conditioner, and instant heater may all work safely on their own, but overload the permitted current when operated together. HDB sets firm limits to prevent tripping, overheating, and unnecessary strain on the building’s shared electrical infrastructure.
Older HDB blocks were built at a time when household demand was very different, so their electrical systems reflect the design standards of that period. Many pre-1980s units operate on a lower incoming load, and the wiring layouts were meant for lighter appliances and simpler living spaces. When these flats go through the Home Improvement Programme, the rewiring and new distribution boards give them a safer and more stable setup, though the overall allowance may still sit below what newer homes receive.
New BTO flats come with a higher supply allowance because the typical household now depends on appliances that draw more power than older installations were designed for. Most units receive a 40A single-phase supply, and that figure forms the basis for planning how the flat will be wired and how the circuits will be arranged. The distribution board divides this supply across lighting, socket outlets, and designated appliance circuits. Each circuit has a fixed rating, and that rating sets the safe operating limit for whatever is connected to it.
Before installing heavier equipment, homeowners should have the electrician review the relevant limits. They check how the circuits are arranged, identify which ones can carry the load, and pick out the areas where a dedicated circuit point is required. This review also makes clear whether the existing supply is sufficient for the new appliances or if the flat should apply for a higher load before the installation goes ahead.
Most HDB flats rely on a mix of essential and high-demand appliances, and each carries its own electrical requirement. Lighting circuits draw relatively little, while general socket outlets support items such as refrigerators, washing machines, desktop computers, and smaller kitchen devices. The heavier loads come from appliances like air-conditioners, instant water heaters, induction hobs, and built-in ovens. A built-in hob or oven draws a high current while operating, and an air-conditioning unit often needs its own circuit once its rating is taken into account.
Load demand in most households rises substantially during the evening. Cooking, shower heating, and air-conditioning often happen within the same hour. If these appliances sit on poorly distributed circuits, the system can trip even if the incoming supply appears sufficient based solely on its rating. A 40A incoming supply helps, but the internal layout matters just as much.
During a site check, an electrician looks at how these appliances are used together. They note the current draw, the circuit arrangement, and the likelihood of overlapping usage. These observations guide decisions on whether the flat needs new dedicated points, circuit separation, or changes to the existing distribution board.
Households often request a higher electrical load when they shift from gas cooking to an induction hob. Induction systems draw a significant amount of current, and most older flats were not designed with this level of demand in mind. A dedicated circuit is usually required, and the existing allowance may not be enough to support it safely.
Multiple air-conditioning units running in the evening can push the flat close to its limit. Each unit increases the overall current drawn by the flat, especially when the compressors start. If several rooms rely on air-conditioning every night, an upgrade becomes necessary to prevent frequent tripping.
Built-in ovens, larger refrigerators, and other heavy kitchen appliances add to the cumulative current demand placed on the flat. These items often need their own circuits, and the incoming supply must have enough headroom to handle them.
Home offices that operate equipment for extended periods, such as workstations, external drives, or auxiliary power units, add a steady load to the flat and may require a review of the existing capacity.
Magic Build’s work on HDB projects often involves checking how the flat’s existing supply matches the appliances the owner plans to install. Our team looks at the wiring condition, the way the circuits are laid out, and the allowance set by the main breaker. If the proposed equipment requires more capacity, we prepare the load figures and handle the submission for approval. We outline the limits of the flat’s supply clearly and in accordance with regulatory requirements and carry out the electrical work according to the rules set for HDB units and SP Group’s approval process.
Feel free to contact us for your queries.
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