Is taking renovation loan advisable for old flat?

Depends on your financials/comfort level, sharing what I think:

• Identify essentials - What renovation is essential - do you really need to hack the floors (or can overlay) or hack a wall / can be creative to rework around the existing? Is an ID required or just contractor to do targetted work? (find out how much each component cost when sourcing ID and compare to contractor). What furnitures/appliances are essentials? Are you going to stay in the house or rent? (Quality of nowadays reno/materials +workmanship are less durable than many years ago but more ex.)
• Financials - after paying HDB downpayment, agent fees (if any), factoring for essential appliances/furnitures (bed, fridge, cleaning), if cash on hand is not enough i.e. eating into emergency funds, not enough for daily needs - then maybe need to borrow. Must ensure borrow, able to pay (won't delay) within 1-2 years on a monthly basis.

There are quite a few factors to consider:

1. What’s your time horizon? How long will you expect to live there? If it’s your permanent home that you expect to retire in, then it’s okay.

2. Renovation costs are sunken costs. It generally doesn’t add much value to the flat if you intend to sell in the future. If you intend to upgrade or downsize in the future, this may result in a negative sale.

3. If I remember correctly, the interest rates for renovation loans are exorbitant. It’s unadvisable unless your monthly income is high. Spend within your means.