if you work it out up to 2012 (not counting the projects that haven't been completed/started?) it works out to:
value (given the rest of the figures/conclusions not sure how much these should be trusted but lets take their word for it anyway): $1,450,000
outstanding loan: $901,000
equity = $549,000
of course if he was to sell everything and even achieve those estimated values, he'd also have some CG to pay which would eat into his net worth.
so in 6 years of property investment he's accumulated about $550k of equity, and then in the first 6 months of this year alone that has been bumped up by another ~$3.2 million based on estimates of uncompleted projects. good enough for Big Brother to call him a multi-millionaire though and use that as one of their main draw-cards for the show!