As we spend time on Minnesota's Iron Range this week, we're introducing some Strong Towns 101 concepts using local data and examples.

For Iron Range cities, as with cities all over North America, post World War II development has been horizontal. Cities and regions have predominantly grown outward -- not upward -- and building styles have become wider and flatter. This is a sharp contrast to pre-Depression development patterns which favored narrower buildings with a greater emphasis on height.

The shift is the result of regulations, financial incentives and technology improvements that create significant advantages for large projects on the periphery of a community and significant burdens for incremental improvements within existing neighborhoods.

This puts today's local governments -- and local taxpayers -- at a great fiscal disadvantage. Building up is the way traditional cities became wealthy. Without an easy path for adding multi-story structures to a community, the city's tax base is essentially capped. Most efforts to grow the community's wealth will end up on the periphery where financial productivity is low and the long term return on investment is nearly always negative.

Consider a 1st Avenue NW in downtown Grand Rapids. In that street there is a fixed public investment -- pavement, curb, sidewalk, pipe, lighting, etc... -- and a long term maintenance obligation. Those are the costs and they are fairly stable. The revenue, however, can vary over time based on how financially productive the properties on that street become.

The way traditional cities built wealth was to increase the tax base while keeping expense stable. More wealth at the same cost. The easiest way to accomplish this is by adding stories.

For example, there is a small bakery in a single story building on 1st Avenue NW. It sits on a lot that is 2/3 of an acre and has a total value of $70,700. The financial productivity of the bakery is $19.78 per square foot, 57% greater than Walmart and 164% greater than Cub Foods. Here is what it looks like.