In most countries the term “engineer” is used loosely. Often people with a trade qualification add experience and find work in a position as some form of “engineer”. The word by itself does not have a legal status and it is quite common for people to work as an engineer without any academic qualification above trade certificate. However around the world there are professional institutions which work to ensure a more rigorous process in defining an engineer. In most cases these institutions stipulate that to make the claim of being a “professional engineer” (PEng) or a “chartered engineer” (CEng), a person needs to apply for membership at a high level. Usually that requires that a person has a 4 year bachelor’s degree or equivalent, plus significant experience, plus peer recognition. Most of these details will be detailed on the website of the institution. There is an international agreement called the “Washington Accord” than many institutes have signed which stipulates the high level membership criteria – see related FAQ.
There are lesser levels of membership in these institutions. Often they will have a level for an “engineering technologist” for those with a 3 year bachelor of technology degree and more limited experience. There may also be a lesser level, “engineering associate”, often known as “Officer” level which means working as a “paraprofessional”. A paraprofessional works under the guidance of a professional (similar to a paramedic working under a doctor’s guidance). It is at this level that often an advanced diploma (and above) can be considered as one criteria for membership of an institution (along with peer review, experience and so on).