Buying a Resale Flat? 8 Electrical Things to Check Before You Commit

Why this matters before you commit

When people view a resale flat, they look at the layout, the light, the floor level, the view and the condition of the kitchen. Almost nobody opens the DB box.

That is understandable and it is also a mistake, because the electrical installation is one of the few things in a flat that is both expensive to put right and completely invisible during a viewing. A tired kitchen announces itself. A twenty five year old electrical installation with no earth leakage protection does not.

The difference matters in the budget. A flat that needs a board replacement and partial rewiring can add several thousand dollars to your renovation, and that money has to come from somewhere, usually from the part of the renovation you actually cared about.

Here is what to look at, in the order you can do it during a viewing.

1. Open the DB box and photograph it

This is the single highest value thing you can do, and it takes thirty seconds. The box is usually above the main door, in the kitchen, or in a service riser. Do not touch anything. Just open the cover and take a clear photo.

What you are looking for: Is there an RCCB? A larger switch with a small test button on its face. If there is not one, the flat has no earth leakage protection. Are there rewireable fuses rather than breakers? How many spare ways are there? Any browning, discolouration or heat damage? Is anything labelled?

A photo of the open board tells an electrician most of what they need to know, and you can send it for an opinion later.

2. Count the sockets, room by room

Flats built before the mid 1990s were wired for a household with a fraction of today's appliances. Two sockets in a bedroom was normal then and is not now.

Walk each room and count. If the numbers are low, that is not a defect, but it is renovation scope, and every added point costs money. Note also whether the wiring is in visible surface trunking or concealed. Surface trunking is cheaper to modify. Concealed wiring means any change involves hacking, patching and repainting.

3. Check for a water heater and how it is supplied

Look in each bathroom. Is there a storage heater, an instantaneous one, or nothing? If there is a heater, is there an isolating switch outside the bathroom or a pull cord inside it? A water heater with no proper isolation and no RCCB in the board is the combination most worth spending money to correct.

4. Look at the aircon arrangement

How many units are installed, and does each have an accessible isolator? Also look at the condition of the trunking on the wall and whether the units look original. A flat with aircon points already in the right places saves meaningful cost.

5. Ask about the supply capacity

Older flats were often provisioned for a 30 amp supply. A modern household with multiple aircon units, a water heater and an induction kitchen frequently needs 40 amps or more. Upgrading involves SP Group and has a lead time attached, so it is much better identified before you commit than in month two of your renovation.

6. Look for evidence of unpermitted work

Signs to notice: sockets that do not match the others, trunking that looks like an afterthought, a socket in a bathroom, wiring that disappears into a wall in a way that looks improvised, or a light fitting connected by a plug into a socket.

This matters beyond aesthetics. Unlicensed modifications generally have to be rectified before a sale can complete, and if you discover them after purchase you inherit the problem. If you spot something, raise it before the option is exercised, not after.

7. Check the wet areas and look up

Look at the ceiling around light fittings, especially in bathrooms and near the kitchen. Water staining, bubbling paint or damp patches near an electrical fitting are worth understanding. Ceiling seepage from the unit above is a known category of dispute in HDB flats and it has an electrical dimension, because water reaching a light fitting or conduit will cause persistent tripping that nobody can trace.

8. Test what you can, politely

With the seller's or agent's permission, switch on the lights in every room. Note anything that flickers, does not come on, or has an obvious delay. Plug your phone charger into a few sockets in different rooms. Sniff for anything acrid near the board or sockets. It sounds odd and it takes a second.

What each finding means for your budget

No RCCB, or old rewireable fuses. Board replacement, commonly S$450 to S$800 for an HDB flat. Treat this as necessary rather than optional.

Board full with no spare ways. Same, if you plan to add any circuits.

Very few sockets. Additional points at roughly S$80 to S$220 each depending on concealment.

No water heater point. Around S$120 per point plus the heater.

Aircon points needed in new positions. Commonly S$120 to S$180 per point.

Original wiring, flat over 25 years old, no work ever done. Budget for an assessment at minimum. Full rewiring, if it turns out to be needed, is renovation scale at S$3,000 to S$7,500.

Adding those up before you make an offer is much more comfortable than discovering them afterwards.

What is normal and not alarming

An older board that has an RCCB, is not heat damaged and has spare ways is fine. Age alone is not a defect. Surface trunking is common in HDB flats and is perfectly acceptable. A couple of dead sockets or a flickering light is usually a small repair, not a systemic problem. Previous electrical work is a good sign rather than a bad one, provided it looks properly done.