It's a very popular option with locals. I was quite stunned when
the smaller storage spaces were no longer available cause a lot of
Singaporeans rented them to store their barang-barang, stuff like
luggage, winterwear, clothes, books, etc.
More and more Singaporeans are venturing overseas to work. Not just
that, more and more prefer to live in uncluttered homes but due to
affluence and lifestyle, they DO have barang-barang so to keep them
out of sight, they're placed into personal storage! 
Do you have THAT much stuff, sbst? You live in a 4-room flat, don't
you?