There's a lot of construction going on in Santiago, most private homes in places where it was hard to see the type of residential or mixed use buildings common in SD, are now being demolished to make way for large projects.
For those families with private homes next to one of these projects it's only logical to either sell or create a project to benefit from the upward trend in construction.
As many have pointed out, most of these projects are a plenty around the DR, with many apartments still vacant on the market. But the whole point missed by a many as well, is that those projects need not sell all the units to pay back the investment or turn a profit. Now with the introduction by the Gov of the new rules to community wealth taxing, if you have a combination of properties with a taxed valued above the non-taxed limit you must pay the fee. That means you'll see a lot more of these units going for rentals or placed in a RE value that's not asking for the Moon and stars...