I think that evidence from China's real estate bubble suggests that no matter how much of a supply excess you build, it might not bring down prices as long as the macro environment favours real estate as an investment, because demand for perceived-as-safe and fast-appreciating investments is nearly infinite. (The excess supply can probably make the eventual bubble pop more dramatic, though, but it seems like it won't be triggered simply by a supply excess).

At the very least, a supply-solution proponent would need to explain how China's property supply glut didn't bring prices down until the government cracked down on credit.