Praise be to Allah.
It is well known that building a resort village involves a number of things that go against sharee’ah, such as making it easy for people to indulge in mixing, wanton display, unveiling, nakedness, alcohol, riba (usury) and many other things that are known to those who work in this area.
The resort villages in your country, especially in the area mentioned, are well known for the many haraam things that go on there.
As that is the case, taking part in building these resorts or helping in that comes under the heading of cooperating in sin and transgression. Allaah says (interpretation of the meaning):
“Help you one another in Al‑Birr and At‑Taqwa (virtue, righteousness and piety); but do not help one another in sin and transgression”
If a person sits with those who are committing sin and does not condemn it, then he bears the same burden of sin as they do, just for sitting with them. Similarly the one who sits with those who mock the signs (or verses) of Allaah bears the same burden of sin as they do, even if he does not mock with them, as Allaah says (interpretation of the meaning):
“And it has already been revealed to you in the Book (this Qur’aan) that when you hear the Verses of Allaah being denied and mocked at, then sit not with them, until they engage in a talk other than that; (but if you stayed with them) certainly in that case you would be like them. Surely, Allaah will collect the hypocrites and disbelievers all together in Hell”
If this is the case of one who sits with them, then how about one who helps them to build the houses in which they will commit evil and disobey Allaah, or houses in which they will mock the signs of Allaah and so on!
You have to advise your bosses that what they are doing is haraam, and that they are partners in sin. If they do not respond, then excuse yourself from doing this work for any reason. For example, you could ask them to transfer you to another site where something permissible is being built, or you could say that it is too far away, or you could take an official holiday.
If you cannot do that – but we do not think that the matter will go that far, in sha Allaah – then look for another job. I ask Allaah to help you to do the right things, for the burdens of this world are lighter than the punishment of the Hereafter.
And Allaah knows best.