As already stated, there are a number of developers, some Cape Verde, Italian, British and Portuguese etc. They all have different standards for building and finishing.
Most of the larger developers have their own websites and they will provide more information on who is managing the project work and some will include more info on materials sourced and used.
There are some developments which were finished several years (and earlier) which from the outside may have flaking paintwork on the ground level as the walls are show the salt coming up from within the brickwork, The sand that they used when building would have previously been taken from the beach, therefor it would have contained quantities of salt. A law was later passed which stated that no beach sand could be used for building projects.
The newer resorts will have been built to a much higher standard and, using imported and clean sand such as sand from inland Mauritania, therefore it should not include any salt.
Some buildings are single bricks for external and inner walls, whilst others will have inner partitioned walls of plasterboard and similar material. There are plenty of comparisons to make and consider.