In Death and Life of American Cities, Jane Jacobs talked about the need for a variety of ages of buildings. Many businesses, such as thrift stores and used book stores that do not have high turn over. These businesses cannot afford to carry the costs of new construction, even if it is amortized over a mortgage. One of the most valuable functions for a city is the chance to offer its residents to turn near nothing, into something. A new restaurant wanting to open or a teacher wanting space to provide singing lessons probably cannot afford to carry the costs of new construction without getting into a lot of debt.
Chain stores and franchises, with a proven business model, are some of the only entities can that can take on the risk and cost of new construction. In many towns across the United States, the lack of old buildings (or what could be better described as a lack of old buildings that can be re-purposed after the first generation of owners have moved on) creates what I call a Copy-and-Paste town.
When we make it difficult to create something from nothing, we stop new businesses from establishing. When only those that are already profitable can expand, this leads to an environment where only the rich have ownership and get richer, and everyone else becomes their employee. You wonder why any new construction is filled with the same old chain stores as you see anywhere in the country and we loose the urban diversity and the corresponding wanderlust.
A lack of old buildings that can be re-purposed is not the only factor that leads to economic polarization. A lack of granularity and the corresponding urban illnesses that come with that, and a lack of public markets and locations for street vendors to try out business opportunities without going all in on a brick-and-mortar location, oppressively high taxes and fees to make it impossible for anything other than the ultra-profitable to survive, are just a few other factors.
In a healthy city, change should be good. It takes a lot of energy to tear something down. It would be better to incrementally adapt what already exists.
For example, the Palace of Versailles was not build all at once, but incrementally over centuries.
What started as a chateau, each generation of king inherited the property and spent their resources expanding it, until it grew into a grand palace. It is not hard to imagine that the cost to construct the Palace of Versailles from scratch into the state is it today would exceed what any one king could afford. Instead, the palace was accomplished by each generation adding on to the work done by a previous generation.
Wealth can accumulate by iterating what already exists. In the same way, a town may not have had the wealth in a single generation to build a great cathedral from scratch, but they can if they set out on a multi-century construction project. Likewise, a city build from scratch within a year is not going to have the same diversity as one that has incrementally grown and adapted over centuries.When to rebuild
In all of these cases, it is better to adapt what already exists, than to demolish and start over again. But, there are times when it makes sense to tear down and rebuild, such as when a building's structure has been neglected that it is impractical to save it. Part of this is economics (which I will talk about in a moment.) We should take good care of our buildings.
I think it was Steve Mouzon who said that "maintenance free" often means "not able to be maintained." We should build with traditional materials that can easily be maintained and age gracefully: Wood can be puttied, sanded, repainted, and if it cannot be, you can turn old wood into wood-chips for garden mulch that will eventually biodegrade. Plaster can be patched up. Stones can be replaced, and broken stones can be reused as is, or cut into smaller stones, or grounded into gravel. Metal can be welded back into shape.
I am digressing a little here and will follow up on this topic in the future, but I am trying to build the case that buildings, when maintained (and lovable enough that we want to maintain them), might be expanded and adapted, but they should not be replaced unless they are going to be replaced with something better. There are always going to be exceptions, although this should generally hold true.
The problem is, however, defining what is "better".A better purpose?
Better could mean a better purpose. Sometimes buildings loose their purpose. Some buildings are made for a specific function, and their architecture and layout reflects that. This is a church, and it looks obviously like a church:
If the building looses its purpose (such as the church, as an organization, moves on), the building often gets destroyed (or sits abandoned, decays, and then gets destroyed.) If it is lovable enough and there are people with the money and will power to do so, the church might get re-purposed, but more likely, it will be abandoned or destroyed. You see this in many American cities that used to have an ornate train station, the trains stop running, so the train station has lost its purpose and gets replaced by something better suited for the current situation.A better economic fit?
Better can mean a better Improvement to Land ratio. Strong Towns assumes that a natural Improvement to Land value ratio is somewhere around 9:1. This means, you would spend approximately $90,000 of improvements (the building) on a parcel of land valued at $10,000. It's very unlikely someone is going to build a $100m sky-scrapper on land that is only valued at $10,000, and nobody is going to put a mobile home on a $1m parcel of land in the core of the city. Strong Towns also points out that as the underlying land value increases but the improvement either stays the same or deprecates, eventually the I/L ratio falls so low (such as 2:1 - a $90,000 house on a $45,000 lot), there is likely that the property will be redeveloped (such as into a $405,000 house.)
In Density Without Zoning I showed how the transportation network affects population density, but it can also affect land values. Transportation infrastructure can either increase land values (by connecting two productive places together - e.g. running a rail-line between Boston and New York City is beneficial to both), or it can redistribute land values.
When you run a highway or a rail line from the middle of a city out to the country side, you increase the value of the previously inaccessible countryside that is now within commuting distance. The law of supply and demand dictates that if you increase supply without any significant change in demand (such as a larger population), the price will fall. So, we can think of this as redistributing the land value from the middle of the city to the land now within commuting distance. People can now build homes on the cheaper land rather than compete for homes in the city, workers that would have worked in the city now work for businesses that serve those new houses - we have this ecosystem of people and businesses spread over a larger land area, and land values in the center of the city are going to reflect that.
In towns all across the United States, we have massively increased the supply of land within commuting distance. We have gone from walking and riding street cars to four lane roads where cars travel at 45 miles per hour. Unless your population has increased 200 fold, the population density and underlying land value has likely fallen.
We know it is ridiculous to build a $100m skyscraper on a parcel of land costing $10,000, and we know that increasing land values increases the likelihood of property being redeveloped, and the opposite is just a true. If land that was previously worth $100,000 had a $1m improvement on it, but now the land value has fallen across the course of a century that it is only worth $10,000, does it justify to keep the $1m building on it?
Buildings are expensive - they require maintenance and usually there is some form of property tax. You need to find owners willing to pay the upkeep or tenants to cover the cost, and as land values are an indication of how desirable the land is, it is unlikely that you will be able to find an owner or a tenant willing to upkeep a $1m building on a $10,000 lot. So, there is an economic incentive to replace the $1m building with a $100,000 building - it brings us back into a more natural L/I ratio.
At the extreme case, which unfortunately is far too common in many American towns, is when it is uneconomical to keep the building (because of mounting maintenance costs), and it is uneconomical to build anything at all (because we have redesigned our city to be car-dependent that no business would want to be located somewhere their customers cannot drive to), so the only viable option is to replace the building with a parking lot.
Replacing buildings in urban areas has gotten so common that the term parking crater was coined. Parking craters look as if a comet fell from the sky and randomly leveled buildings.
Parking lots are so worthless, the value of a parking lot is essentially the underlying land value so under a property tax system, you are just paying the tax on the now cheap land and not the improvement (in some American states, property taxes do not get reevaluated for decades unless the property is sold, so even when land prices increase, there is often no incentive to redevelop the parking lot into something better.) Since surface parking lots pay very little in taxes, they are often owned by land speculators, who are in the business of holding on to land for a very long time, hoping to sell at a profit in the far future. Since parking lots pay very little in taxes, land speculators are incentivized to keep it that way.
Most of us would not consider replacing a $1m with a $100,000 building or even a parking lot would be "better", but it might be better economically, and that disconnects creates mistrust.The problem with loosing what we have
In many cases, it is illegal to rebuild what is torn down. With zoning and land use laws such as parking requirements, setback requirements, maximum lot coverage ratios, minimum lot sizes, even if land values did increase, often what should be a positive change ends up being suburban in character. Sometimes, you cannot even rehabilitate a 'grandfathered in' building because it is not up to code. We have made it illegal to rebuild our best neighbourhoods.
The United States has a shortage of quality urban neighborhoods because we have made it illegal to build neighborhoods as we used to. You cannot just pick a random suburb and start building another Beacon Hill.
Modern urban planning has scarred us. Change should be good. But, during a century of reconfiguring our cities to be based around the automobile making old forms obsolete, where infrastructure "investments" often meant devaluing the urban core and turning buildings into garages and parking lots, watching our communal wealth being destroyed, where modern building codes and zoning regulations prevent us from building more of our best stuff, change has been bad.
Visit this website for many before and after aerial views of how modern urban planning has changed our cities.
I do not blame cities that form historical districts and try to glass case entire neighborhoods, or citizen advocacy groups that fight to prevent old buildings from being modified because a century of change has often resulted in a worse outcome. We need a better way.