On average it would cost around $2,000 to rewire a 5-room HDB flat in Singapore. This cost can vary depending on the age of the apartment, the complexity of the wiring, the materials and services required. Prices may also differ from one contractor to another, and some may offer more affordable prices than others. In most cases, the cost also includes labour for wall chasing, conduit installation, cable laying, switch and socket installation, as well as testing and certification. For larger and more complex properties, the price can be higher due to more complex wiring tasks.