Trade-offs Are Everywhere

If you look around the world and consider the decisions that people have to make, you will see trade-offs everywhere. It’s very rare that we are in situations of such total resource abundance that making one choice will not take some other choice off the table.

Consider designing a building—a situation that is fraught with trade-offs. All construction must consider trade-offs, because there is no way any particular building can have and be everything everyone wants. We must answer questions like: Who are we designing for? What is the purpose of the building? What kind of functionality does it need to have, now and in the future? These kinds of questions will force us to make choices, some of which take away other options. For example, durability and cost are often two competing parameters. “If we make the structure too weak, we may save weight and money, but then the chance of the thing breaking too soon will become unacceptably high,” writes J. E. Gordon in Structures. On the other hand, “if we make a structure so strong that, in human terms, it is likely to last ‘forever’—which is what the public would like—then it will probably be too heavy and expensive.”[5] The useful trade-off is: cheap enough to get built now, durable enough to last some useful amount of time. A wood-frame house, for example, may cost less to build than a stone one, while the desired lifespan and maintenance needs also enter the choice.

Some people still build stone houses, bunkers, and other dwellings that are meant to last beyond a couple of generations. People evaluate trade-offs differently, so although trade-offs are often objective (such as certain materials impacting the amount of time a building is likely to be usable), they can sometimes be subjective (such as the value of living close to work or family, or buying in an older building that has historic appeal). When it comes to buildings, “There are no ‘optimal’ solutions applicable to all projects. Solutions can only satisfy certain people at certain times.”[6] That’s why all houses aren’t the same. We all weigh each decision factor in construction uniquely, in accordance with our needs, resources, and desires.

Let’s break down cost versus longevity in construction a little more. Bundled in with the idea of longevity is adaptability: Can your building adapt with the times? In a practical context, answering this question might require looking at something like occupant capacity. If we are designing an office building for today, and our organization has one thousand employees, should we design for exactly that amount? What if we grow? What if a recession hits? How adaptable can we be without creating too much waste or driving up the initial cost too much? If we design for two thousand employees, there’s going to be a lot of empty space at the beginning, unless we can figure out some productive but temporary uses for it. But then we have to design for those too.

The number of trade-offs we have to make in a situation like this can seem overwhelming. So, another lesson about trade-offs is to not consider them so extensively that we get into analysis paralysis.

Take adaptability in building construction. Some factors are likely to make a building more adaptable, such as space that can be reconfigured and materials that will withstand a range of environmental changes. Adaptability, though, does not need to be (and cannot entirely be) planned. We humans are fairly adaptable ourselves, and if the structure is still standing and its condition is sound, we’ll probably be able to find a use for it. The Parthenon started as a temple to the goddess Athena. In its 2,500-year history, it has been a church, a mosque, and a storehouse for munitions. None of these uses was intended by its original designers, but the Parthenon has proved highly adaptable.

This discussion of adaptability leads us to another complexity of trade-offs: they are not always easy to identify and quantify. The costs of one material versus another are clear, but the trade-offs between functionality and enjoyment of a space are less so. Furthermore, any built structure is “highly contextual, responding to constraints specific to geographic location, built environment, the immediate site, occupant characteristics, and the availability of resources.”[7] Thus, trade-offs are not two-dimensional; often many dimensions have to be considered. If we innovate in a building’s design to keep future costs down or increase future adaptability, what effect do we have not only on structural utility but on ongoing maintenance? A great design may cost less in the building phase but require expensive upkeep. Certain functions may be sustainable but impact the enjoyability of the environment or limit the building’s potential uses.

It is therefore important to realize that in reality, trade-offs are not usually a simple “item A or B but not both” equation. They tend to be more complex: If this, then not that, so then this other thing, which means maybe more or less of the original, plus something new that reduces the ability to do something else later on…maybe. If all these other variables stay consistent, which they won’t. (Possible throwing up of hands at this point.)

Different priorities and constraints lead people to make different compromises. That helps explain why buildings vary so much.

It’s trade-offs that give us difference, including cityscapes with tall skyscrapers made of steel and glass next to stone churches and three-story brick buildings. They are what give us log cabins and wrap-around porches and treehouses and the odd geodesic dome. Each building is designed to meet the needs of people who have a unique perspective on what trade-offs they are willing to make in environments with local parameters that influence what those trade-offs look like.

For a particular project, identify the requirements that must be met and the features on which compromise is possible. Then compare the effects over the building’s life, including maintenance and potential changes of use.

Abundance does not just allow us to buy more goods. It affords us the luxury of packing poorly, the luxury of not having to think, as well as the luxury of not minding mistakes.

—Sendhil Mullainathan and Eldar Shafir[8]