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The Nest founder tells of years in pursuit of a thermostat he actually likes

Tony Fadell shows off the Nest thermostat in 2012.

The thermostat chased me for 10 years.

That is pretty extreme, by the way. If you’ve got an idea for a business or a new product, you usually don’t have to wait a decade to make sure it’s worth doing.

For most of the 10 years that I idly thought about thermostats, I had no intention of building one. It was the early 2000s, and I was at Apple making the first iPhone. I got married, had kids. I was busy.

But then again, I was also really cold. Bone-chillingly cold.

Every time my wife and I drove up to our Lake Tahoe ski cabin on Friday nights after work, we’d have to keep our snow jackets on until the next day. The house took all night to heat up.

Adapted from the book BUILD: An Unorthodox Guide to Making Things Worth Making by Tony Fadell. Copyright 2022 by Tony Fadell. Reprinted by permission of Harper Business, an imprint of HarperCollins Publishers.

Walking into that frigid house drove me nuts. It was mind-boggling that there wasn’t a way to warm it up before we got there. I spent dozens of hours and thousands of dollars trying to hack security and computer equipment tied to an analog phone so I could fire up the thermostat remotely. Half my vacations were spent elbow-deep in wiring, electronics littering the floor. But nothing worked. So the first night of every trip was always the same: We’d huddle on the ice block of a bed, under the freezing sheets, watching our breath turn into fog until the house finally warmed up by morning.

Then on Monday I’d go back to Apple and work on the first iPhone. Eventually I realized I was making a perfect remote control for a thermostat. If I could just connect the HVAC system to my iPhone, I could control it from anywhere. But the technology that I needed to make it happen—reliable low-cost communications, cheap screens and processors—didn’t exist yet.

How did these ugly, piece-of-crap thermostats cost almost as much as Apple’s most cutting-edge technology?

A year later we decided to build a new, superefficient house in Tahoe. During the day I’d work on the iPhone, then I’d come home and pore over specs for our house, choosing finishes and materials and solar panels and, eventually, tackling the HVAC system. And once again, the thermostat came to haunt me. All the top-of-the-line thermostats were hideous beige boxes with bizarrely confusing user interfaces. None of them saved energy. None could be controlled remotely. And they cost around US $400. The iPhone, meanwhile, was selling for $499.

How did these ugly, piece-of-crap thermostats cost almost as much as Apple’s most cutting-edge technology?

The architects and engineers on the Tahoe project heard me complaining over and over about how insane it was. I told them, “One day, I’m going to fix this—mark my words!” They all rolled their eyes—there goes Tony complaining again!

At first they were just idle words born of frustration. But then things started to change. The success of the iPhone drove down costs for the sophisticated components I couldn’t get my hands on earlier. Suddenly high-quality connectors and screens and processors were being manufactured by the millions, cheaply, and could be repurposed for other technology.

My life was changing, too. I quit Apple and began traveling the world with my family. A startup was not the plan. The plan was a break. A long one.

We traveled all over the globe and worked hard not to think about work. But no matter where we went, we could not escape one thing: the goddamn thermostat. The infuriating, inaccurate, energy-hogging, thoughtlessly stupid, impossible-to-program, always-too-hot-or-too-cold-in-some-part-of-the-house thermostat.

Someone needed to fix it. And eventually I realized that someone was going to be me.

This 2010 prototype of the Nest thermostat wasn’t pretty. But making the thermometer beautiful would be the easy part. The circuit board diagrams point to the next step—making it round.Tom Crabtree

The big companies weren’t going to do it. Honeywell and the other white-box competitors hadn’t truly innovated in 30 years. It was a dead, unloved market with less than $1 billion in total annual sales in the United States.

The only thing missing was the will to take the plunge. I wasn’t ready to carry another startup on my back. Not then. Not alone.

Then, magically, Matt Rogers, who’d been one of the first interns on the iPod project, reached out to me. He was a real partner who could share the load. So I let the idea catch me. I came back to Silicon Valley and got to work. I researched the technology, then the opportunity, the business, the competition, the people, the financing, the history.

Making it beautiful wasn’t going to be hard. Gorgeous hardware, an intuitive interface—that we could do. We’d honed those skills at Apple. But to make this product successful—and meaningful—we needed to solve two big problems:

It needed to save energy.

And we needed to sell it.

In North America and Europe, thermostats control half a home’s energy bill—something like $2,500 a year. Every previous attempt to reduce that number—by thermostat manufacturers, by energy companies, by government bodies—had failed miserably for a host of different reasons. We had to do it for real, while keeping it dead simple for customers.

Then we needed to sell it. Almost all thermostats at that point were sold and installed by professional HVAC technicians. We were never going to break into that old boys’ club. We had to find a way into people’s minds first, then their homes. And we had to make our thermostat so easy to install that literally anyone could do it themselves.

It took around 9 to 12 months of making prototypes and interactive models, building bits of software, talking to users and experts, and testing it with friends before Matt and I decided to pitch investors.

Once we had prototypes of the thermostat, we sent it out to real people to test.

It was fatter than we wanted. The screen wasn’t quite what I imagined. Kind of like the first iPod, actually. But it worked. It connected to your phone. It learned what temperatures you liked. It turned itself down when nobody was home. It saved energy. We knew self-installation was potentially a huge stumbling block, so everyone waited with bated breath to see how it went. Did people shock themselves? Start a fire? Abandon the project halfway through because it was too complicated? Soon our testers reported in: Installation went fine. People loved it. But it took about an hour to install. Crap. An hour was way too long. This needed to be an easy DIY project, a quick upgrade.

So we dug into the reports—what was taking so long? What were we missing?

Our testers...spent the first 30 minutes looking for tools.

Turns out we weren’t missing anything—but our testers were. They spent the first 30 minutes looking for tools—the wire stripper, the flathead screwdriver; no, wait, we need a Phillips. Where did I put that?

Once they gathered everything they needed, the rest of the installation flew by. Twenty, 30 minutes tops.

I suspect most companies would have sighed with relief. The actual installation took 20 minutes, so that’s what they’d tell customers. Great. Problem solved.

But this was going to be the first moment people interacted with our device. Their first experience of Nest. They were buying a $249 thermostat—they were expecting a different kind of experience. And we needed to exceed their expectations. Every minute from opening the box to reading the instructions to getting it on their wall to turning on the heat for the first time had to be incredibly smooth. A buttery, warm, joyful experience.

And we knew Beth. Beth was one of two potential customers we defined. The other customer was into technology, loved his iPhone, was always looking for cool new gadgets. Beth was the decider—she dictated what made it into the house and what got returned. She loved beautiful things, too, but was skeptical of supernew, untested technology. Searching for a screwdriver in the kitchen drawer and then the toolbox in the garage would not make her feel warm and buttery. She would be rolling her eyes. She would be frustrated and annoyed.

Shipping the Nest thermostat with a screwdriver "turned a moment of frustration into a moment of delight"Dwight Eschliman

So we changed the prototype. Not the thermostat prototype—the installation prototype. We added one new element: a little screwdriver. It had four different head options, and it fit in the palm of your hand. It was sleek and cute. Most importantly, it was unbelievably handy.

So now, instead of rummaging through toolboxes and cupboards, trying to find the right tool to pry their old thermostat off the wall, customers simply reached into the Nest box and took out exactly what they needed. It turned a moment of frustration into a moment of delight.

Sony laughed at the iPod. Nokia laughed at the iPhone. Honeywell laughed at the Nest Learning Thermostat.

In the stages of grief, this is what we call Denial.

But soon, as your disruptive product, process, or business model begins to gain steam with customers, your competitors will start to get worried. And when they realize you might steal their market share, they’ll get pissed. Really pissed. When people hit the Anger stage of grief, they lash out, they undercut your pricing, try to embarrass you with advertising, use negative press to undermine you, put in new agreements with sales channels to lock you out of the market.

And they might sue you.

The good news is that a lawsuit means you’ve officially arrived. We had a party the day Honeywell sued Nest. We were thrilled. That ridiculous lawsuit meant we were a real threat and they knew it. So we brought out the champagne. That’s right, f---ers. We’re coming for your lunch.

With every generation, the product became sleeker, slimmer, and less expensive to build. In 2014, Google bought Nest for $3.2 billion. In 2016 Google decided to sell Nest, so I left the company. Months after I left, Google changed its mind. Today, Google Nest is alive and well, and they’re still making new products, creating new experiences, delivering on their version of our vision. I deeply, genuinely, wish them well.

Tony Fadell started his thirty-plus-year Silicon Valley career at General Magic, went on to make the iPod and IPhone, and started Nest. He now leads investment and advisory firm Future Shape.

Not a very accurate narrative. Retrofit programmable thermostats were sold at big box hardware stores long before the Nest was introduced. I replaced my old dumb thermostat with one several houses ago. He could easily have put in a thermostat programmed to have his cabin warm when he arrived for the weekend. It wouldn't have all the bells and whistles of a Nest, but he wouldn't have been freezing for the first day of the weekend. And of course suitable connectors, processors, and the like for a thermostat were available long before the iPhone was a thing.

I was an early adopter of smart thermostats. My dirt-simple Honeywell gold plastic circular thing with a bit of mercury on a bimetal coil was taken out of service and I replaced it with one of those programmable thermostats and I spent an evening reprogramming it. I presented my efforts to my wife and she couldn't make heads or tails of what she had to do to warm things up or cool things off. A twist of the dial was replaced by a flurry of button presses and a hard-to-read screen. And then the batteries died just after I forgot how to reprogram the thing and/or lost the booklet. We went through three or four such thermostats. My wife, strangely, did not divorce me. When the Nest came out, we had been burned several times, it wasn't fun, and we both longed for the simple Honeywell gold plastic circular thing. Nevertheless, I installed the Nest, programmed it, and showed my wife how to set the temperature.

She cried tears of joy. I felt like a skunk for the prior decade and a half of unnecessary vexation I caused her.

It's not enough to introduce the technology, but to make sure it's sophisticated enough to be simple to operate.

Your weekly selection of awesome robot videos

Video Friday is your weekly selection of awesome robotics videos, collected by your friends at IEEE Spectrum robotics. We also post a weekly calendar of upcoming robotics events for the next few months. Please send us your events for inclusion.

Chengxu Zhou from the University of Leeds writes, “we have recently done a demo with one operator teleoperating two legged manipulator for a bottle opening task.”

If you like this and are in the market for a new open source quadruped controller, CMU’s got that going on, too.

A bolt-on 360 camera kit for your drone that costs $430.

I think I may be too old to have any idea what’s going on here.

I’m not the biggest fan of the way the Stop Killer Robots folks go about trying to make their point, but they have a new documentary out, so here you go.

Error-riddled astronomical tables inspired the first computer—and the first vaporware

Allison Marsh is a professor at the University of South Carolina and codirector of the university's Ann Johnson Institute for Science, Technology & Society. She combines her interests in engineering, history, and museum objects to write the Past Forward column, which tells the story of technology through historical artifacts.

During Charles Babbage’s lifetime, this 2,000-part clockwork was as near to completion as his Difference Engine ever got.

It was an idea born of frustration, or at least that’s how Charles Babbage would later recall the events of the summer of 1821. That fateful summer, Babbage and his friend and fellow mathematician John Herschel were in England editing astronomical tables. Both men were founding members of the Royal Astronomical Society, but editing astronomical tables is a tedious task, and they were frustrated by all of the errors they found. Exasperated, Babbage exclaimed, “I wish to God these calculations had been executed by steam.” To which Herschel replied, “It is quite possible.“

Babbage and Herschel were living in the midst of what we now call the Industrial Revolution, and steam-powered machinery was already upending all types of business. Why not astronomy too?

Babbage set to work on the concept for a Difference Engine, a machine that would use a clockwork mechanism to solve polynomial equations. He soon had a small working model (now known as Difference Engine 0), and on 14 June 1822, he presented a one-page “Note respecting the Application of Machinery to the Calculation of Astronomical Tables” to the Royal Astronomical Society. His note doesn’t go into much detail—it’s only one page, after all—but Babbage claimed to have “repeatedly constructed tables of squares and triangles of numbers” as well as of the very specific formula x2 + x + 41. He ends his note with much optimism: “From the experiments I have already made, I feel great confidence in the complete success of the plans I have proposed.” That is, he wanted to build a full-scale Difference Engine.

Perhaps Babbage should have tempered his enthusiasm. His magnificent Difference Engine proved far more difficult to build than his note suggested.

It wasn’t for lack of trying, or lack of funds. For Babbage managed to do something else that was almost as unimaginable: He convinced the British government to fund his plan. The government saw the value in a machine that could calculate the many numerical tables used for navigation, construction, finance, and engineering, thereby reducing human labor (and error). With an initial investment of £1,700 in 1823 (about US $230,000 today), Babbage got to work.

The 19th-century mathematician Charles Babbage’s visionary contributions to computing were rediscovered in the 20th century.The Picture Art Collection/Alamy

Babbage based his machine on the mathematical method of finite differences, which allows you to solve polynomial equations in a series of iterative steps that compare the differences in the resulting values. This method had the advantage of requiring simple addition only, which was easier to implement using gear wheels than one based on multiplication and division would have been. (The Computer History Museum has an excellent description of how the Difference Engine works.) Although Babbage had once dreamed of a machine powered by steam, his actual design called for a human to turn a crank to advance each iteration of calculations.

Difference Engine No. 1 was divided into two main parts: the calculator and the printing mechanism. Although Babbage considered using different numbering systems (binary, hexadecimal, and so on), he decided to stick with the familiarity of the base-10 decimal system. His design in 1830 had a capacity of 16 digits and six orders of difference. Each number value was represented by its own wheel/cam combination. The wheels represented only whole numbers; the machine was designed to jam if a result came out between whole numbers.

As the calculator cranked out the results, the printing mechanism did two things: It printed a table while simultaneously making a stereotype mold (imprinting the results in a soft material such as wax or plaster of paris). The mold could be used to make printing plates, and because it was made at the same time as the calculations, there would be no errors introduced by humans copying the results.

Difference Engine No. 1 contained more than 25,000 distinct parts, split roughly equally between the calculator and the printer. The concepts of interchangeable parts and standardization were still in their infancy. Babbage thus needed a skilled craftsman to manufacture the many pieces. Marc Isambard Brunel, part of the father-and-son team of engineers who had constructed the first tunnel under the Thames, recommended Joseph Clement. Clement was an award-winning machinist and draftsman whose work was valued for its precision.

Babbage and Clement were both brilliant at their respective professions, but they often locked horns. Clement knew his worth and demanded to be paid accordingly. Babbage grew concerned about costs and started checking on Clement’s work, which eroded trust. The two did produce a portion of the machine [shown at top] that was approximately one-seventh of the complete engine and featured about 2,000 moving parts. Babbage demonstrated the working model in the weekly soirees he held at his home in London.

The machine impressed many of the intellectual society set, including a teenage Ada Byron, who understood the mathematical implications of the machine. Byron was not allowed to attend university due to her sex, but her mother supported her academic interests. Babbage suggested several tutors in mathematics, and the two remained correspondents over their lifetimes. In 1835, Ada married William King. Three years later, when he became the first Earl of Lovelace, Ada became Countess of Lovelace. (More about Ada Lovelace shortly.)

Despite the successful chatter in society circles about Babbage’s Difference Engine, trouble was brewing—cost overruns, political opposition to the project, and Babbage and Clement’s personality differences, which were causing extreme delays. Eventually, the relationship between Babbage and Clement reached a breaking point. After yet another fight over finances, Clement abruptly quit in 1832.

Ada Lovelace championed Charles Babbage’s work by, among other things, writing the first computer algorithm for his unbuilt Analytical Engine.Interim Archives/Getty Images

Despite these setbacks, Babbage had already started developing a more ambitious machine: the Analytical Engine. Whereas the Difference Engine was designed to solve polynomials, this new machine was intended to be a general-purpose computer. It was composed of several smaller devices: one to list the instruction set (on punch cards popularized by the Jacquard loom); one (called the mill) to process the instructions; one (which Babbage called the store but we would consider the memory) to store the intermediary results; and one to print out the results.

In 1840 Babbage gave a series of lectures in Turin on his Analytical Engine, to much acclaim. Italian mathematician Luigi Federico Menabrea published a description of the engine in French in 1842, “Notions sur la machine analytique.” This is where Lady Lovelace returns to the story.

Lovelace translated Menabrea’s description into English, discreetly making a few corrections. The English scientist Charles Wheatstone, a friend of both Lovelace and Babbage, suggested that Lovelace augment the translation with explanations of the Analytical Engine to help advance Babbage’s cause. The resulting “Notes,” published in 1843 in Richard Taylor’s Scientific Memoirs, was three times the length of Menabrea’s original essay and contained what many historians consider the first algorithm or computer program. It is quite an accomplishment to write a program for an unbuilt computer whose design was still in flux. Filmmakers John Fuegi and Jo Francis captured Ada Lovelace’s contributions to computing in their 2003 documentary Ada Byron Lovelace: To Dream Tomorrow. They also wrote a companion article published in the IEEE Annals of the History of Computing, entitled “Lovelace & Babbage and the Creation of the 1843 ‘Notes’.”

Although Lovelace’s translation and “Notes” were hailed by leading scientists of the day, they did not win Babbage any additional funding. Prime Minister Robert Peel had never been a fan of Babbage’s; as a member of Parliament back in 1823, he had been a skeptic of Babbage’s early design. Now that Peel was in a position of power, he secretly solicited condemnations of the Difference Engine. In a stormy meeting on 11 November 1842, the two men argued past each other. In January 1843, Babbage was informed that Parliament was sending the finished portion of Difference Engine No. 1 to the King’s College Museum. Two months later, Parliament voted to withdraw support for the project. By then, the government had spent £17,500 (about US $3 million today) and waited 20 years and still didn’t have a working machine. You could see why Peel thought it was a waste.

But Babbage, perhaps reinvigorated by his work on the Analytical Engine, decided to return to the Difference Engine in 1846. Difference Engine No. 2 required only 8,000 parts and had a much more elegant and efficient design. He estimated it would weigh 5 tons and measure 11 feet long and 7 feet high. He worked for another two years on the machine and left 20 detailed drawings, which were donated to the Science Museum after he died in 1871.

In 1985, a team at the Science Museum in London set out to build the streamlined Difference Engine No. 2 based on Babbage’s drawings. The 8,000-part machine was finally completed in 2002.Science Museum Group

Although Difference Engine No. 2, like all the other engines, was never completed during Babbage’s lifetime, a team at the Science Museum in London set out to build one. Beginning in 1985, under the leadership of Curator of Computing Doron Swade, the team created new drawings adapted to modern manufacturing techniques. In the process, they sought to answer a lingering question: Was 19th-century precision a limiting factor in Babbage’s design? The answer is no. The team concluded that if Babbage had been able to secure enough funding and if he had had a better relationship with his machinist, the Difference Engine would have been a success.

That said, some of the same headaches that plagued Babbage also affected the modern team. Despite leaving behind fairly detailed designs, Babbage left no introductory notes or explanations of how the pieces worked together. Much of the groundbreaking work interpreting the designs was done by Australian computer scientist and historian Allan G. Bromley, beginning in 1979. Even so, the plans had dimension inconsistencies, errors, and entire parts omitted (such as the driving mechanism for the inking), as described by Swade in a 2005 article for the IEEE Annals of the History of Computing.

The team had wanted to complete the Difference Engine by 1991, in time for the bicentenary of Babbage’s birth. They did finish the calculating section by then. But the printing and stereotyping section—the part that would have alleviated all of Babbage’s frustrations in editing those astronomical tables—took another nine years. The finished product is on display at the Science Museum.

A duplicate engine was built with funding from former Microsoft chief technology officer Nathan Myhrvold. The Computer History Museum displayed that machine from 2008 to 2016, and it now resides in the lobby of Myhrvold’s Intellectual Ventures in Bellevue, Wash.

The title of the textbook for the very first computer science class I ever took was The Analytical Engine. It opened with a historical introduction about Babbage, his machines, and his legacy. Babbage never saw his machines built, and after his death, the ideas passed into obscurity for a time. Over the course of the 20th century, though, his genius became more clear. His work foreshadowed many features of modern computing, including programming, iteration, looping, and conditional branching. These days, the Analytical Engine is often considered an invention 100 years ahead of its time. It would be anachronistic and ahistorical to apply today’s computer terminology to Babbage’s machines, but he was clearly one of the founding visionaries of modern computing.

Part of a continuing series looking at photographs of historical artifacts that embrace the boundless potential of technology.

An abridged version of this article appears in the June 2022 print issue as “The Clockwork Computer."