Land is very much a limited resource. But most of the problems today are due to the distribution and consumer wants. In much of the US, you could easily buy some land and put a trailer or small manufactured house on it (or buy forclosed, vacant, etc). The problem is the jobs, especially the good ones, are concentrated in a dozen or so major metro areas with higher population density. The. You have the preference of most people who want good public schools, yards, big fancy single family houses, etc. Most people don't want a small house, and due to the job distribution can't live in the less populated areas.