At 74, veteran public servant Tan Gee Paw still thinks about how Singapore should develop as a city.

After retiring last year as chairman of water agency PUB, he was near the city centre one day when the sight of skyscrapers led him to the idea that a three-day week in the office is enough to get work done, as it is possible to work the other days from home. That might revolutionise "the shape and structure of our urbanisation" as office buildings will consume less utilities and workers commute less.