Each province dictates its own rules and limits in terms of how much can be built, where, and how. In Las Terrenas, Samana, for example, they are different building zones. Each of these zones has its specific limits and requirements.
The most important ones being the building density which is the number of bedrooms one can build per hectare.
Here is an example with you owning a 2,000 Sqm lot:
In that specific zone, the building density is 30 bedrooms per hectare (or 10,000 Sqm or 2.47 Acres). 2,000 Sqm is a fifth of a hectare. So 30 bedrooms / 5 = 6. You’ll be authorized up to 6 bedrooms, no more. That being said, you can build as many rooms as you want within the other building parameters set.
Below you can find the map with the building density per zone. The area includes: from El Catey to Playa el Valle, Coson to El Portillo and Playa Las Ballenas to el Portillo. The following maps are from the Ministry of Tourism Dominican Republic, April 26, 2012.