Building cheaper moderately-high-density housing doesn't really compete with single-family detached houses; it competes with housing further from the core. In

Building cheaper moderately-high-density housing doesn't really compete with single-family detached houses; it competes with housing further from the core. In fact, with higher general density, you'd expect your lot to become more valuable, since it can now potentially be sold to developers. There's also the knock-on effects of higher economic growth and shorter commute times on property values and available amenities, and broadening the tax base, potentially reducing your tax burden. If you tore down all the skyscrapers in Manhattan, your brownstone wouldn't get more valuable; rather the opposite.