Hello, I'm having a good day today! Thank you for asking. I hope you're doing well, too.
This is a good question for a professional. Since I have never done any construction projects, I can only answer as a common person. It sounds to me like "building project" is a more general term, and "housing project" is specific to houses that people will live in. If you think about it, "building" means all structures that people go into and use, while a "house" is usually a place where people live, sleep, or eat.