It works like this. You are new here so the local banks don't know you, so if you got a long time to get residence and set up a relationship you might get a 50% mortgage at 8% interest.
There are international banks but as you can read on the web most are gone, or nearly gone. You will even see banks here with public apologies on their homepage about people unable to get their money. Your money is not easy to transfer in and very hard to transfer out with these pint size banks.
That leave developer loans. Be very careful, they probably will tell you as security they must hold your title. Big red flag. That's not owning that is renting to own. They know 8 out of 10 walk away after a few years and they are free to “sell it “ again and again.
In Belize there are mortgages on titles, they cost a bit to set up, if your developer is sincerely legit they will finance you with a true mortgage on the deed you hold, in your own name. If they say that is called a thing called a Caution, in Belize... that's a lie. A caution is more like a builder lien and often dismissed in courts, if your only claim is a caution on the title you own nothing. If a local Belize bank gave you a mortgage, you would get the title just like at home, anything else is not real financing. NEVER do anything without getting a Belize lawyer to advise you.
Don't forget when you go to sell, your next buyer will not have financing either it can take years to get your money back as you play bank.
Remember Belize does not regulate Realtors or Developers. Also recourse on faulty construction is almost nil. They can be a shifty as any used car salesman at home. This is not where you're from, and the rules are simpler here, with far less consumer protection.