HDB Rewiring Cost (2026): 3-Room to Executive Flats

A full rewire replaces every circuit from the DB box to each switch and socket, and usually the DB box itself.

A complete quote normally covers:

• New cables for lighting and 13A socket circuits, and dedicated circuits for each water heater, aircon system and cooker.
• New switches, sockets and ceiling points.
• A new DB box with a main switch, a 30 mA RCCB and one breaker per circuit, labelled.
• PVC trunking or conduit, and removal of the old wiring.
• The licensed electrical worker's testing and certification, and the HDB-endorsed Form CS/5H submission to SP Services (part of SP Group).

Light fittings, fans, hacking, patching, painting, false ceilings, carpentry and data points are usually extra. Ask for each one in writing.

The RCCB isn't optional. Every home must have an RCCB or a working ELCB, and since 1 Jul 2023 the Energy Market Authority (EMA) requires 30 mA RCCB protection on a home's socket and lighting circuits (EMA: 30 mA RCCB circular). For the box alone, see HDB DB box replacement cost and whether an RCCB is compulsory in Singapore.

Most electricians use 1.5 mm² cable for lighting, 2.5 mm² for sockets and 4 mm² or 6 mm² for an instant heater or cooker. The licensed electrical worker sizes each circuit to Singapore Standard SS 638, the code of practice for electrical installations.

Advertised rewiring packages typically assume about 8 to 14 light points and 10 to 14 socket points, rising with flat size.

Most socket points in these packages are double sockets. Add one dedicated circuit per water heater, aircon system and cooker.

Count your own points before asking for quotes: walk each room and note every light, socket, heater and aircon unit you want. Ask whether a double socket counts as one point or two, because quotes differ. HDB sets no limit on the number of points, but the total is limited by your main switch rating.

For single extra points without a rewire, see power socket installation or light installation.

Not in new grooves. HDB doesn't allow new wiring to be embedded in walls, columns, beams, slabs or plaster, even inside conduit.

HDB's rule is "no embedding of wiring (housed in metal/ high impact PVC conduit)" in structural elements, wall plaster or other finishes (HDB: Electrical works). Unauthorised works must be removed, made good or reinstated. Be wary of any quote offering to chase grooves into walls.

That leaves surface or concealed routes. PVC trunking or surface conduit is the cheapest and needs no HDB permit. Concealed runs hide the cable inside a false ceiling, boxing or carpentry, which looks neater but costs more.

In some flats, an electrician may be able to pull new cable through the original hidden conduits. Ask whether a quote assumes this, and what happens if a conduit is blocked.

No. HDB lists rewiring, extra light and 13A points, and PVC trunking as works that need no permit, subject to its guidelines (HDB: Electrical works).

The main exception: in flats without higher electrical loading (a 30A main switch), new 15A points and 20A isolators need an HDB permit. Flats with a 40A main switch, or upgraded under the Main Upgrading Programme (MUP) or Home Improvement Programme (HIP), don't. HDB allows a 20A isolator only for an air-conditioner, and appliances above 15A aren't allowed. Items not listed in HDB's guidelines also need its approval.

In 30A flats, HDB also limits an instant water heater, oven, cooker or washer with heater to 3 kW each, and a storage heater to 1.5 kW.

Two more HDB rules shape the plan. Power points aren't allowed in bathrooms. Contractors may work 9am to 6pm on weekdays and Saturdays; noisy work (hacking, heavy drilling, tile cutting) 9am to 5pm on weekdays only; never on Sundays, public holidays or the eves of New Year's Day, Chinese New Year, Deepavali, Hari Raya Puasa and Christmas.

An EMA licensed electrical worker (LEW) must do or supervise the work, test and certify it, and apply to SP Services for inspection before use.

Under section 82 of the Electricity Act, only an LEW, or someone working under one, may do electrical work, and knowingly engaging an unlicensed person is an offence (Electricity Act, s82). EMA says the LEW's work "includes any rewiring" and that the LEW certifies the installation is safe before power is turned on (Ask.gov.sg: EMA).

HDB says that after testing, the LEW submits SP Services form CS/5H endorsed by HDB. SP Services, part of SP Group, must accept the inspection application before the new wiring is used, and it spot-checks selected jobs on site. The first inspection is free; if one fails, a re-inspection fee is payable.

More points, dedicated heater and aircon circuits, concealed runs and making good raise the price. Compare quotes line by line, not by total.

The main cost drivers:

• More points, especially extra aircon, heater and cooker circuits.
• Concealed runs in false ceilings or carpentry.
• Dismantling old wiring, then patching and painting.
• Moving the DB box.
• A permit case: new 15A points or an aircon isolator in a 30A flat.

When you compare quotes, check each one lists:

• Points by type and count, and the price of each extra point.
• Cable size for each circuit.
• The route: trunking, conduit or concealed.
• The DB box, its number of ways, and the 30 mA RCCB.
• Removal of old wiring and making good.
• The LEW's name, certification, and the Form CS/5H submission to SP Services.

For an accurate price, send your floor plan, a photo of the DB box with its door closed, and a list of points to add or remove. If you're unsure it's needed at all, read whether your resale HDB flat needs rewiring. For other jobs, see the full electrician price list for Singapore.