Hi. My name's Sarah, and I've been priced out of the housing market. In fact, I'm one of the majority of my generation who can't afford a home. And in 2017, home ownership amongst young Australians has fallen to the lowest level in recorded history. So, foolishly or otherwise, I decided to build my own home. But the prognosis wasn't good there, either. Architects cater for the one percent, builders are scarce, so service is inconsistent and prices are high. The single biggest investment in my life, and I was amazed how little self-determination, choice and, ultimately, control I had. What's more, I was doubly surprised at how vulnerable this made me feel. Frankly, I felt trapped. So, I reflected on this for quite some time. And I realized what I wanted was democratized design and construction. And that led to me asking one very simple question: What is building a house? What is it? Well, it turns out that building a house is making a series of decisions, some with physical consequences, within a defined set of parameters. Now, having worked in software applications for some time now, this all sounded very familiar to me. I also couldn't understand why we build on-site. No other major assembly in our lives is constructed like this. Your car doesn't come to you in pieces with an extra 10 percent just in case, to be assembled at the mercy of the elements. So why should your house? So I built a computer game. A game that allows you to design your home and have it delivered to you. A game that puts the home builder back at the center of the largest purchase in their life, elevating them from spectator to player. A game with full visibility of the costs and environmental impact of each new attribute you add. Using modular components, players select items from their library and drag them into their world. Each item, be it a wall, a solar battery or even an armchair, contains all of the information for the system to calculate costs, environmental impact and even a happiness tally for the player. Eighty-three percent of home builders said that next to cost, environmentally friendly features were the most important things to them. So out of the gate, homes are integrated with solar systems. Born green. Sustainable housing is often associated with wealth and affluence, but that shouldn't be the case. In fact, truly sustainable housing should be available to everyone and affordable for all. So, I had found a way to get the control back that I was craving and give it to others. But something was still bugging me, something was still keeping me up at night. What about those people who have genuinely no control over where they live? Every hour -- in the space of your intermission -- 4,000 new homes are needed in the world. Wrap your head around that number. That's an astonishing 35 million homes globally, every year. And in Australia alone, we have a shortfall of 250,000 dwellings. And in addition to that, we have 190,000 families on the assisted-housing wait list; families in need of a home. Between now and 2050, when the global population is set to move from today's 7.6 billion to tomorrow's 9.8 billion people, hundreds of millions of people will experience security, health and safety issues. Imagine if you can not feeling secure in your home -- not from crime, not from theft, but from the fact that the building you're in -- the building you're in -- might not be structurally sound or built from nontoxic components or meet local natural disaster standards. It's the 21st century. And this just isn't good enough. What if -- what if -- we could restore control and dignity to those individuals by giving them a home, but not just any home: their home, and a home of their design. We're currently adapting our game so that when a player builds a home, they're contributing to a home for someone in need. And I know this sounds like a lofty goal, and it is ridiculously ambitious, but today, our current operating model operates at a ten-to-one ratio. So for every 10 homes we build, we can build a home for someone in need. (Applause) This is made possible because today, with design for manufacture and assembly, which uses light gauge steel frame construction, shipped and assembled on-site, we can decrease construction costs by 20 percent and environmental waste by 15 percent, saving time, money and keeping tons of waste out of landfills. The power in modular construction is that you can build year-round with confidence in your costs, in your quality, and in your delivery date, in your build date. Now, wouldn't that be crazy? Wouldn't that be great? But -- that doesn't get me to my goal. My goal is one-for-one. So I've been traveling the world, looking at different alternatives of construction 3-D printing, trying to find technology that will help me deliver on my ambition. 3-D printing is so exciting and so promising, offering a 40 percent reduction in cost and near zero waste. And this is just to name a few, but some of the really exciting innovations happening all over the world are happening in Italy, France, Dubai and Australia. And they use robotic arms to print everything from solid stone to concrete, to wax. In Italy, they have developed a technique using sorel cement. Sorel cement was originally invented in 1867, and it's the beautiful chemical marriage of magnesium oxide and local sand, which they can now use to print solid stone walls. And in France, they have a regulator-approved although still experimental process where they print two parallel tracks of foam insulation and pour concrete in the middle to create solid stone. And in Dubai, sitting at the foot of those two glorious Emirates Towers, is a vision of the future in the middle of the desert. They've got their experimental office of the future, which is constructed using 3-D printed concrete which was printed in China and shipped and assembled on location in Dubai. And not to be outdone, in Australia, we've pioneered an amazing technology that allows you to print wax molds and pour concrete over the top of them, allowing you to create really intricately beautiful and cost-effective facades that you can see in person the next time you travel the London Underground. But all of these things are tools -- hammer of tomorrow, if you like. And the one common thread that connects all these things is computer-aided design. We will need models to build using these techniques, models like the ones being developed by players in our game. I want to put every person that wants one in a home of their own design. And there are many more applications still. We could usher in an entirely new empowered experience of special needs or aged-care accommodation. And we could provide rapid, on-site assistance in emergency housing situations. In the words of one of my players, "I want to take matters into my own hands and live by example." Thank you. (Applause)