HDB's website says that for a 4-room flat with a market value of S$450,000 today and a leftover lease of 65 years, if the home "owners" choose to keep 30 years of their lease, they can sell the tail-end of the last 35 years of the lease to the government.
And how much is the last 35 years of the lease? Only S$190,000.
So there you have it, you have your answer. If you have a flat which has 65 years left on its lease now, and the flat value is S$450,000 now, the flat value will decline to S$190,000 after 30 years. This also means that in the next 30 years, S$260,000 of your flat value will be wiped out.
Based on the government's calculations, if you chart it out, this means that the value of your flat will start declining almost immediately after the 35th year. It might not even be after 50 or 60 years like some academics have estimated.
It will look something like this:
35th year: S$450,000
45th year: S$360,000
55th year: S$270,000
65th year: S$190,000
75th year: S$150,000
85th year: S$100,000
95th year: S$50,000
99th year: S$0
This is another of the government's example: for a 3-room flat which is worth S$350,000 now and has 64 years left on its lease, the flat value will decline to S$148,000 after 30 years, which again means that in the next 30 years, S$202,000 of your flat value will be wiped out.
It will look something like this:
35th year: S$350,000
45th year: S$280,000
55th year: S$210,000
65th year: S$148,000
75th year: S$100,000
85th year: S$60,000
95th year: S$30,000
99th year: S$0