However, the result was far from clear cut as just 52pc supported bringing the age down by two years.
The decision means that the proposal will now go to Government, which will then decide whether to hold a referendum on the matter.
Some 57pc of delegates opposed a proposal to reduce to five years the length a president spends in the Aras.
The members also voted by 94pc to 6pc in favour of a proposal for citizens to be given a say in the nomination process of presidential candidates.
And an overwhelming four out of 10 voted against holding the presidential election on the same day as the local and european elections.
The Constitutional Convention -- which comprises of citizens, politicians and an independent chairman -- was established in order to make decisions on important societal and political issues.
The group met in Malahide on the weekend in what was its first major voting session since its formation.
Some 66 of the delegates are made up of randomly selected citizens, while 33 of those in attendance were politicians.
Sinn Fein came under criticism after it emerged that party leader Gerry Adams and deputy leader Mary Lou McDonald opted to send substitutes in their place.
Fine Gael chairman Charlie Flanagan said he felt it was important parties "would put their best foot forward" for the convention and treat it with respect.
However, Sinn Fein senator David Cullinane -- who was one of the substitutes -- said that Mr Adams and Ms McDonald will attend future sessions.
Meanwhile, the attention will now switch to a raft of other issues set to be voted upon --such as same sex marriage and civil partnership.
Constitution chairman Tom Arnold said the meeting allowed members to have a "meaningful input" into important issues.
"I believe we witnessed real citizen-focussed democracy whereby people considered all aspects of the debate before deciding on their own preferences," he said.
"We will continue this initiative in the coming months when we examine issues such as same-sex marriage and electoral systems."