Eden failed to win £50m from the Big Lottery Fund's Living Landmarks: The People's Millions programme last year, but Eden Project founder Tim Smit said he would raise cash to build the arid plants dome through a bond scheme to be launched later this year.
He said: "We will get The Edge financed by the end of the year. We are going to be using unusual methods to raise the money by issuing a future bond."
Smit said the launch date was yet to be decided for the bond, which a bank will underwrite and syndicate or sell on to other banks and investors, who will receive a pre-determined interest or coupon payment, potentially at a high rate on a loan for such an unusual project.
Bond broker RIA Capital Markets senior manager Paul Lomas said: "Something like the Eden Project would have to pay quite a high return to borrow money, especially in the current climate. It is difficult to find funding in current market conditions."
Smit spoke as he and botanist David Bellamy launched the Ultimate Eco House at the Ideal Home Show in London last week. The show has an eco theme and the house highlights sustainable living with its green roof, vegetable beds and eco-friendly construction.
Smit said: "I've always been interested in eco-construction and the Eden Project brought sustainable construction to a level where we set new standards.
"I'm very interested in opening this Eco House for the same reason as we did Eden, because the country is starting a programme of a huge amount of new building and this will suggest the changes we need to be making so it is hugely significant. In one way, I wish it was not called Eco House because I'd like to be in a situation where it is unthinkable not be building sustainable buildings."
Smit said the plethora of projects dubbed "the new Eden Project" showed a lack of imagination by designers. "In some ways it is flattering ... but it shows rather a paucity of imagination."
He also said he intends to "bring the country to standstill with the largest participatory event in British history" in July 2009, but would not elaborate further.
Smit added that Eden had children's outdoor play projects lined up for 2008. "We need to say outdoors is not a place of threat to play in. Evidence suggests the vast majority of kids are not allowed to play outside because it is seen as dangerous."
He said the replacement of Eden curator Tom Keay would be appointed from a shortlist of three next week. "I was very pleasantly surprised by the quality of the candidates ... Each one of the three shortlisted is worthy of the job."