HDB Resale Flat Inspection Checklist: Plumbing, Electrical & Aircon Red Flags

Use an authorised viewing to collect evidence, separate cosmetic wear from service risks, and decide which questions or specialist checks should shape your renovation budget.

Published 16 July 2026 | Reviewed 16 July 2026 | By All-in-One Fix & Move | Reviewed by All-in-One Fix & Move

Quick answer: Check for active or historic water marks, slow drainage, damaged fittings, scorched or cracked electrical accessories, repeated tripping, weak aircon cooling, condensate leaks, rust and strong vibration. Photograph each clue with the seller's permission, ask for relevant records, and obtain a properly licensed or trained specialist's assessment before pricing a material repair.

When should a buyer use this HDB resale checklist?

Use it during a viewing only with the seller's or agent's permission, and use a fresh copy for the pre-completion inspection that HDB asks buyers to arrange with sellers. The first pass helps you identify questions and possible budget items. The final pass helps you compare the flat's visible condition and contents with what the parties agreed.

Do not start renovation work before resale completion. Do not move, dismantle or test somebody else's fixtures without consent. If a condition could materially affect your decision, timing or price, obtain independent professional and legal advice suitable for the transaction.

What should you bring to a viewing?

• A phone for time-stamped notes and photographs, subject to permission.
• A small torch for looking into open, accessible cabinets; do not enter service ducts or ceiling voids.
• A simple floor-plan printout so every observation has a room and wall reference.
• Tissue to check an accessible dry surface for moisture without undoing a fitting.
• A written list of fixtures and fittings that are meant to remain after completion.

Keep the inspection non-invasive. Normal operation means turning an accessible tap, light switch or aircon remote on and off with permission. It does not mean opening a distribution board, removing socket covers, climbing onto an aircon ledge, lifting floor-trap parts, forcing valves or carrying out a live test.

Which red flags deserve a specialist check?

How do you inspect HDB resale plumbing without dismantling anything?

Start with patterns rather than diagnoses. Check the kitchen, both sides of bathroom walls, service yard, water-heater area and the ceilings below or beside wet areas. If the seller permits normal operation, run one fixture at a time so you can connect a symptom with a particular use.

1. Look before running water. Note existing droplets, dark grout, peeling paint, swollen laminate, rust trails, sealant gaps and staining inside open cabinets.
2. Operate accessible taps normally. Observe flow, splashing at joints, movement at the tap base and whether water drains without pooling. Do not force a stiff valve.
3. Flush each toilet with permission. Watch for continuous refilling, movement at the base, slow discharge or backflow. Do not lift or dismantle the cistern.
4. Use your nose and ears. Record persistent foul odour, gurgling or water sounds after use has stopped.
5. Recheck after several minutes. A slow joint or drain leak may appear only after the fixture has been used.

A visible symptom can be documented through the water-leak diagnosis service page; the broader Singapore plumbing service guide explains common scopes. For an evidence-led meter method that is suitable only when you have permission and access, read the hidden water leak and meter-test guide.

Licence boundary: PUB states that regulated water service and sanitary plumbing works must be carried out by a PUB Licensed Plumber, apart from listed simple plumbing works that a handyman may perform. A buyer's visual check does not determine which category a later repair falls into; confirm the actual scope before engagement.

How do you inspect the electrical system safely?

Keep this part visual and operational. With permission, switch accessible lights and fixed fans on and off normally. Note rooms where lights flicker, switches feel loose, accessories are cracked, cover plates are missing or appliances appear to rely on chains of adaptors and extension leads.

• Distribution board: look only at the closed exterior. Photograph any visible damage, rust, missing blanking pieces or unclear circuit labels. Labelling and a neat exterior do not prove the circuits have been tested.
• Switches and socket-outlets: do not touch a damaged, wet, hot or buzzing accessory. Do not use improvised testers, remove a cover or insert a tool.
• Trip history: ask whether trips recur and what equipment is usually running. A verbal answer is context, not a diagnosis.
• Past works: ask what was rewired or added and whether the responsible LEW and applicable HDB or testing records can be identified.
• Renovation planning: list intended high-load equipment early. The existing number of outlets does not prove that the installation can support a proposed layout.

EMA says electrical installation, repair or modification work, adding or replacing power points, and consumer-control-unit or circuit-breaker work should be carried out or supervised by an LEW. Use the electrical service scope page for planned work, the power-trip diagnosis page for recurring trips, and the DB, MCB and RCCB guide for terminology before discussing an LEW assessment.

How do you inspect an HDB resale flat's aircon?

Ask the seller to operate every fan-coil unit in cooling mode under comparable settings. A short viewing cannot prove long-term performance, but it can reveal differences that deserve follow-up. Record the set temperature, start time, airflow, sound, odour and whether water appears during the test.

1. Inspect indoor units before starting. Look for staining below the casing, damaged trunking, loose covers and dark or wet pipe insulation.
2. Compare airflow and cooling. One weaker unit may have a local issue; all units performing poorly may have a different cause. Neither pattern proves that a full replacement is required.
3. Listen for change. Rattling, grinding or strong vibration matters more when it persists after startup.
4. Trace accessible condensate clues. HDB requires condensate to discharge properly to a nearby floor trap and pipe joints to be insulated against condensation and dripping. Do not undo trunking or a drain connection.
5. Observe the condenser from a safe interior position only. Do not climb onto or lean over an aircon ledge. Photograph visible rust, vibration or support concerns from inside.

HDB states that air-conditioner installation must follow its approved locations and methods, while BCA explains that a trained air-conditioning unit installer is required for units fitted on a building's exterior or an outward-projecting surface. For service triage, see the aircon water-leak page and aircon service overview. For replacement planning, use the Singapore aircon installation guide.

What records should you ask the seller or agent about?

Missing records are a reason to investigate, not automatic proof of an unauthorised or unsafe installation. Conversely, a receipt or approval does not prove that current condition is satisfactory. Match documents to the exact item, date and scope visible in the flat.

What is the best room-by-room inspection order?

1. Start at the entrance. Record the viewing date, unit, occupants present and agreed fixtures that should remain.
2. Photograph the closed DB exterior. Note its location and visible condition without opening it.
3. Walk every dry room once. Scan ceilings, wall corners, skirting and the wall shared with a bathroom or service yard.
4. Operate accessible lights and fans. Stop immediately at damage, moisture, heat, buzzing or a burning smell.
5. Inspect the kitchen dry. Look below the sink, around appliance hoses and at cabinet bases before running water.
6. Check each bathroom one fixture at a time. Revisit the adjacent room after taps and toilets have been used.
7. Inspect the service yard and water-heater area. Keep clear of wet electrical equipment and do not force valves.
8. Run each aircon unit with permission. Use comparable settings and note airflow, cooling, noise, odour and moisture.
9. Return to earlier moisture points. Delayed droplets, refilling sounds or a growing patch are easier to spot on a second pass.
10. Close with documents and next actions. Separate cosmetic items, specialist checks and renovation-budget items; do not diagnose from photographs alone.

How should red flags change your renovation budget?

Price confirmed scope, not fear. Put each observation into one of three buckets:

• Immediate specialist review: water near electricity, burning smell, damaged live accessories, repeated tripping, active leakage, unsafe-looking aircon support or severe backflow.
• Investigation before budgeting: old stains, intermittent odour, slow drains, uneven cooling, damaged insulation or undocumented alterations.
• Planned renewal: functioning but dated fixtures or equipment that you intend to replace for layout, efficiency or preference.

Ask for an itemised scope that states what is being inspected, repaired, replaced and excluded. Keep provisional allowances separate from confirmed quotations. The Singapore renovation cost planning page can help organise those allowances after the technical scope is clearer.

Official references

• HDB: Resale Flat Completion for Buyers
• HDB: Approval of Resale Flat Application for Sellers (Branch inspection scope)
• HDB: Renovation Guidelines for Electrical Works
• EMA: Engaging Licensed Electrical Workers
• PUB: Plumbing Works and Licensed Plumber Requirements
• HDB: Renovation Guidelines for Air Conditioner Installation Works
• HDB: Maintaining Air Conditioners in HDB Flats
• BCA: Air-Conditioning Safety and Trained Installers