The half-assed solution is progressive taxation. Your first plot will be taxed very little. Every plot after that more and more.

It's not perfect because it is basically a subsidy to owner occupants so it won't help suburbs become denser. However, it disconnects the impact of taxation on home owners and commercial developers/investors which means home owners will be more willing to tax developers. The one benefit is that large scale development will naturally consider denser housing because they want to optimize their tax burden.