Unfortunately it doesn’t seem like you’ll be eligible to join the competition. You have to understand this event is tailored towards undergrad students, and you guys are on y our second masters, having completed your undergrad more than 4 years ago.
The only reason why we have the 18 months rule for master’s students is because in some countries a master is mandatory in order to graduate. Some countries have a 5-year undergrad program and others have a 4 years undergrad + 1 year master. It’s the same but divided and named differently. The 18-month rule is made for those kind of students.
We do encourage you to take the competition’s brief and use it for your thesis project if you wish to do so, and we will be happy to assist you in answering any questions you may have if you choose to do so.
The arkitekturo team