However, his girlfriend and one of their male friends, who reached the door first, were told that they could enter.
"As you can imagine, we were both shocked and embarrassed at his response considering the ages within our group," Mr Allan said.
"I didn't want to cause a scene. It was embarrassing enough being turned away for that reason."
Respectably dressed and not overly intoxicated, he said he struggled to find any reason why they would not be allowed in.
"We had had a few drinks at the barbecue, but we certainly weren't in a state where you would not let us in. If we were, as a group, we would have accepted his position a bit better. If we were unruly, but we were not at all. We have never, ever encountered that before anywhere," Mr Allan said.
"I wonder if they would say that to a woman. Maybe they thought we were predators, but picking us out for that reason is shocking."
The handful of people in front of them in the queue were very young, he noted.
"Surely this is age discrimination, which I believe is a direct breach of our human rights. Would this not be the same as not allowing someone of a different culture or race entrance to an establishment that is open to the general public?
"All of our group are responsible individuals who, like many others, enjoy a night out. This situation was both degrading and embarrassing and put a dampener on our evening."
Glenn Meikle, owner of Temple Bar, said the bar manager had no knowledge of the incident.
"It could have happened, and if it did happen we're very disappointed, but it's definitely not a policy to say stuff like that."
Mr Meikle said the bar did not discriminate against patrons because of age.
"We can't do that. We do have a target market but the only thing I can think of is these older guys might not have fit the dress code."
Mr Meikle said there were only three reasons patrons were denied entry into Temple Bar - not meeting the dress code, intoxication and being underage.
At 42, Mr Meikle said he did not feel comfortable socialising at Temple Bar.
"I don't feel right there, it's not my scene."
Student bars in Auckland also said they welcomed all ages - and in fact older patrons might be asked to show ID as a matter of habit.
The manager of Albany student bar the Ferguson, Andrew Waite, said the bar had a standard dress code but would not discriminate by age.
When the age issue has arisen in the past, including at a hen party in Hamilton two years ago and a Wellington student bar in 2008, the Human Rights Commission said bars could not exclude people on the basis of age, gender, sexual orientation, political or religious beliefs.
