I have unlocked most technologies and still have not unlocked some buildings such as the residential tower, i have all the technologies leading to it and even some drones yet not unlocking buildings.
Make sure you have the resources to build them. For some, if you haven't started producing the resource or imported it, they won't show up. For example, any building that has to do with Regolith on the red planet, won't show up unless you import some.