The first thing to do is to consult the builder in networks, see what other projects they have executed and the opinions of the customers.
Second, if you are going to buy in pre-sale, please verify that you are paying directly to the trust (“fiduciaria” in Spanish) that collects the initial fees and not directly to the builder. It is a law in Colombia to have a trust fund in pre-sales, if they do not have one, it is better to withdraw your proposal.