Form Follows Function

011 min

The problem Form Follows Function answered

In the early 1890s, Louis Sullivan, an American architect, faced a kind of building that nobody had designed before. Steel frames let an office building rise far higher than stone walls could, and elevators made the upper floors worth renting. There was no model for how such a tower should look.

Most architects of the time borrowed a model. They covered the new towers with temple and palace fronts, piled one above another, so that one tall building looked like several short ones. Before Sullivan, architects tried to hide how tall their steel-framed buildings were, and he argued that a tall building should look tall. He was also the teacher of a young Frank Lloyd Wright, who worked as his assistant.

A claim like that needs a rule behind it, short enough to apply to every floor and every window. In 1896 Sullivan wrote one.

021 min

Where Form Follows Function comes from

Louis Sullivan introduced the phrase in an essay from 1896 called The Tall Office Building Artistically Considered. The argument is short. He pointed to the eagle in flight, the open apple blossom and the branching oak, and called it a law that form ever follows function. In plain words, what a living thing does decides what it looks like.

The word "ever" matters. Sullivan meant that the link holds every time, so a thing whose job stays the same keeps its shape, and a new job needs a new shape. A skyscraper was a new job. It therefore had no reason to copy a temple.

The idea is older than the phrase. People often credit it to Horatio Greenough, an American sculptor who died in 1852, but the wording is Sullivan's. Greenough admired animal bodies, machines and ships, and argued that the right shape for a building follows from what the building does. A monk named Carlo Lodoli voiced a similar thought in the 1700s, and Sullivan himself traced the core idea back to Vitruvius, the Roman author who asked that a building be solid, useful and beautiful.

What changed in 1896 was the target. The older advice told architects to follow precedent, which means the look of earlier buildings. Sullivan told them to follow purpose.

031 min

How Form Follows Function works

Sullivan did not begin with a drawing. Sullivan began from a list of what the building had to do, because he believed every problem holds the outline of its own solution.

For a tall office building, the list in his essay has five parts:

• Below ground: the boiler, engines and other machines that supply power, heat and light.
• Ground floor: stores and banks, which need large areas, plenty of light and easy entry.
• Second floor: space reached by stairs, also with wide openings.
• Middle: offices, floor after floor.
• Top: an attic holding tanks, pipes and valves.

Look at the fourth item. In his list, the office floors above the shops were alike, tier after tier. If the job does not change from one floor to the next, the form should not change either. The middle of the Wainwright Building in St. Louis, finished in 1891, therefore repeats one pattern of tall brick piers and windows. The base and the top have different jobs, so they look different.

The form has a second task. Sullivan wrote that life is recognizable in its expression, so a person on the street should be able to read the building. Here is the shop level, here are the offices, and here is the machinery. The shape is not a disguise for the use. It is how the use becomes visible.

041 min

Did Form Follows Function ban ornament?

Readers of that slogan often conclude that Sullivan wanted plain buildings. His own work says otherwise. The band at the top of the Wainwright Building is covered in carved leaves, and Sullivan held that ornament could serve a purpose of its own, such as making a building more representative. In other words, decoration counted as one of the building's jobs.

So where did the ban come from? Adolf Loos, an Austrian architect, wrote an essay called Ornament and Crime that attacked decoration. Later modernists, among them Walter Gropius, who founded the Bauhaus school, took Loos's attack and Sullivan's slogan as one message. They also showed steel, glass and concrete as they were, instead of covering them up.

The two ideas are not the same, though. Sullivan's rule allows ornament that does a job. Loos's rule did not. When people say that a plain glass box follows function, they are repeating the modernists, not Sullivan.

051 min

What counts as function

If decoration can be a job, the next question is how far "function" reaches. Wright, who had worked under Sullivan, thought the slogan was too narrow. In a draft press release for the Johnson Wax headquarters in 1936, he said that building strictly by it produced thin buildings, and he preferred to say that form and function are one.

Later designers widened the word instead. Dieter Rams, an industrial designer, said in an interview recorded by designboom that a product has psychological functions as well as the plain function of working. He did not call them extras. He called them very important functions.

That changes what the designer's list contains. A radio has to receive stations, and it also has to be something people are willing to keep in a room. Both go on the list.

062 min

Form Follows Function in everyday design

The idea can be tested on objects people handle every day, starting with a door. Donald Norman, a cognitive scientist and usability engineer, used doors to show how a form can say what to do. In his account, a flat plate on a door tells people to push, and a bar or handle tells them to pull. When the form says the right thing, the door needs no sign.

A web page can follow the rule too. In Smashing Magazine's 2010 reading, the Google home page was built around one job, which was to let a visitor type a query in the box. So it carries almost nothing else.

Now the other side. Apple's Magic Mouse 2 has its charging port on the underside, so the owner has to turn it upside down to charge it and cannot use it meanwhile. A mouse is made to be used with its underside down. The maker put one job where it blocks the main job. The shape is tidy, but a plain task, moving the pointer while the battery is low, has lost out to it. Critics of the mouse call this form beating function.

Two cases show the range. The Wainwright Building made function visible, floor by floor. The mouse hid a function behind a neat shell. The difference is not taste. It is whether the person who designed the shape asked what the user would be doing at that moment.

072 min

Where Form Follows Function is contested

The mouse suggests that function should always win. Several objections say it is not that simple.

Read the study carefully. It measured how usable layouts looked, not how well people did with them. It does not show that beautiful screens work better. It shows that appearance and function cannot be separated in the user's mind, so a design that follows function but ignores looks can still be judged a failure.

The same study found something awkward for the rule. Many of the rules designers use to make a layout efficient showed little link to how usable the layout looked. A designer can follow function correctly and still not be believed.

082 min

Applying Form Follows Function

These moves come straight from Sullivan's method and from the cases above.

1. 1

   Write the jobs first.

   Before sketching a screen or a product, list what it must do for each kind of user, the way Sullivan listed what a tall building must hold. For a settings page the list could be: find a setting, change it, see that the change took effect.

2. 2

   Give repeated jobs one form.

   If twenty rows do the same job, make them look the same. A difference in look should always mean a difference in job.

3. 3

   Make the form say what to do.

   A plate says push and a bar says pull. A control on a screen should look like what it does.

4. 4

   Count feelings as jobs.

   If people must trust a payment screen, the screen has to look trustworthy. This is Rams's point about psychological functions.

5. 5

   Test the look as well as the use.

   Looks change judgments, so ask people how easy a design seems, and also time them on a task.

The rule fails in two ways. The first is when "function" means only what the maker needs, which is how the mouse got its charging port. The second is when a designer removes everything that is not strictly necessary, and the product then feels cold to people who must live with it. When a product has several purposes, the rule also gives no answer until someone decides which one comes first.

091 min

Form Follows Function vs. nearby concepts

Form follows function tells a designer how to decide. The neighbours below describe what a user sees or judges, or give the tools for making form show function.

?4 questions

Questions people ask

§10 sources

Sources