"The way we have been brought up is with this 9 to 5 mindset."
But she said employers needed to see the benefits in terms of attracting and retaining staff and encourage a cultural shift by leading from the top.
"What we have realised is it is very much a tone from the top."
Westpac adopted a "leave loudly" policy last year.
Dellabarca said what it had learned was business leaders needed to be open about what they were doing and show that to others.
It was also vital to communicate flexibility by talking about it often and celebrating it as well as reinforcing the fact that there was no dip in productivity from people working offsite.
"Part of it is treating people like adults and letting it work for them."
Men felt less need to sneak out quietly (18 per cent) than their female counterparts (23 per cent).
Internal staff research show women were more likely to use flexible working options than men but Dellabarca said flexibility was not just something for women.
"It is just as important for male employees to have flexibility as well. Flexibility should work for both men and women."
She said flexibility could allow men to spend more time with their kids as they were growing up and give more balance to modern families where often both parents were working.
Workers under the age of 35 (28 per cent) were far more likely to sneak out quietly than those over 55 (10 per cent).
"This suggests that under-35s desire greater flexibility, but don't feel comfortable about how that is viewed by others," she said.
Dellabarca said there was a perception that flexibility had to be earned but she said it should be the starting point with every role.
"The workforce is becoming more diverse and flexible, and employers are going to have to respond to those changing attitudes if they want to attract the best people to their company."