This thesis demonstrates that housing is becoming less and less affordable in some urban areas (with my focus being two test cases, America and Australia) and if current trends continue affordability in some of these areas will worsen. The thesis outlines how this constitutes a series of threats to the community and focuses in particular upon the middle-class. Increase in supply is one obvious mechanism to improve affordability and in this regard the town planning system plays an important role. The thesis argues that the telos of the town planning system is to provide housing and that utilitarianism provides the right moral framework to achieve that aim. From this perspective, there is greater benefit to facilitating real estate development than there is to conservation, but that conservation still remains a worthy objective that carries considerable weight under the utilitarian calculus.