What is a reasonable sum to spend on a 4-room BTO? What percentage of your income should you be using (i.e. healthy) to pay the HDB loan per month?

Hi Anon, the maximum I would allow myself and my clients to pay for mortgage or even rent would be 30% of your annual income. This goes hand in hand with the value of your home that should be at max be 5 - 7 X Annual Income.

So if each spouse makes 50k/yr for example, the max cost of home should be between 500-700k, but the lesser the better. And thus, mortgage should be at max 30k/yr or 2.5k/mth.

Now for a 4-room flat, of course mature and non-mature estates would have different price points and location plays a big part. I feel as long as you follow the above rule, it'll be fine.