At the turn of the century, an ambitious young engineer started a two-month contract with a beleaguered technology company struggling to rekindle its glory days. He had eight weeks to design a brand new device in an area that the firm had no history in, and convince upper management that it was worth betting the company on. What he created in those eight weeks grew into the first iconic product of the 21st century. The eight weeks became nine years, and the next product he worked on revolutionised the computer industry almost overnight.

"We changed the world twice – I was very lucky," says Tony Fadell of his decade-long spell at Apple devising the iPod and leading engineering on the iPhone. It is the sort of legacy that stands alongside that of anyone in the technology business, and it would be almost impossible to imagine how to follow it up with a second act.

But Fadell is not the sort of individual who is content to rest on his laurels, and with his new company, Nest Labs, he has been working to extend the design sensibility that he honed at Apple to a product category that has traditionally been among the worst designed products we are forced to interact with – the discrete pieces of technology we use in our homes on a daily basis, beginning with the thermostat and, recently, the humble smoke alarm.

It might seem that, compared to the iPod and iPhone, devices such as the thermostat and the smoke alarm are the least sexy devices one could imagine. But listening to Fadell, it sounds like the most natural progression of all.

“Before, we had portable CD players and MP3 players, and people were like ‘what are you getting into that for, it’s tapped out, there’s no money to be made’,” he says in a rapid-fire patter. “The same with the phone market. If I look at every single market that we went into, and then crushed, there’s a lot in common when you go to look at something like the thermostat: huge existing market, fully commoditised, with a bunch of entrenched competition, people don’t think you can reinvent the category at all. You go again with smoke alarms. I don’t believe the warnings. I’m like ‘Are you kidding me, that’s a great market for innovation. People see problems, I see opportunities. When people go it’s daunting, there’s no money in it, nobody really cares – perfect. Big market, nobody cares, no new technology has been applied, the competitors haven’t innovated for years. Let me in, sign me up.”

That eagerness to reinvent moribund markets is paying off handsomely. Two years ago, Nest unveiled a thermostat unlike any that had ever been seen before. There were no fiddly settings and inscrutable instructions, just a beautiful round dial and glass display. But it wasn’t merely a more intuitive, user-friendly thermostat – it was a net-connected learning thermostat with motion sensors, designed to optimise your home’s heating patterns based on your needs and habits.

Fadell’s vision for home improvement doesn’t stop there. At the Web Summit yesterday, he was showing off the Nest Protect, which reinvents the smoke alarm. Beautifully designed with a subtle sunflower pattern surrounding a large circular button (“We design our products to appeal to women,” he says), the Nest Protect uses a human voice recording as an initial alert, allowing you to gesture at the device if it’s merely some burnt toast rather than the early stages of a serious conflagration. It also solves some of the other enduring problems posed by existing smoke alarms – the low-battery warning is another voice recording, rather than an incessant ping, so as not to drive you to disconnect the thing out of distraction.

In terms of their beautiful design, attention to detail and elegant packaging, the Nest products are clearly sharing in Apple's gene pool. After working with Steve Jobs for nearly a decade, Fadell is quick to acknowledge the influence and inspiration he takes from his former workplace.

"It was absolutely inspiring at Apple, and Steve was for sure, but so were so many people there. And it was really the team that came together, and we'd sit in the boardroom, and there would be 15 of us, and Steve would be leading the meeting, and then we'd be throwing out ideas, and we'd build on each other. And you start putting this thing together, and you start looking at it from all angles," he gestures with both hands revolving around each other, "that swirling happens, you're bringing something that not any one person could ever have thought of, that's what's so much fun. And when I see that happening in our meetings, when I see people now doing the things that we would do to get ready for Steve, I kind of go 'Wow, this is pretty cool.' A day doesn't go past that we don't think about our time at Apple."

Nest is the one of the first firms to be making waves in the long-anticipated, but awkwardly named, “Internet of Things”, the vision of ubiquitous network-connected devices that communicate with one another and can be controlled centrally, from a smartphone app for instance.

Fadell dislikes the name, understandably, but is clear about the prospects. “I started using computers back in the 70s, and in this very nascent, ‘connective things’ area, we’re still in the late 70s or early 80s. We’re in the Apple days, we haven’t hit the Macintosh yet. It’s going to take some time, I think we’re just at the very cusp. How long did it take to get to the ‘internet of computers’? There are so many layers of software and hardware to be built, and standards to be built, that I do believe it’s a 10-year proposition, easily.”