Kate Lawler is hoping to hire out the Big Brother house for her big sister Kelly's wedding reception later this year.
The unusual venue costs up to £30,000 a night to hire.
It is intended for hire for corporate events, but organisers say they will make an exception for the series winner.
Explaining how she planned to spend her £70,000 prize money, Kate told OK! magazine: "I'm going to pay for my sister Kelly's wedding or honeymoon, and I've suggested we have the reception in the Big Brother house.
"They're hiring it out so we could have a pool party."
Endemol UK is turning the house in Elstree Studios, Hertfordshire, into a party venue from next month. Event organiser Skybridge has put together a range of packages for partygoers costing from £18,000 to £30,000 a night.
A Skybridge spokesman said: "The house is for hire for corporate events rather than private parties, but I'm sure for Kate we could make an exception."
Kate, 22, from Beckenham, Kent, said she also planned to spend her money on paying off her parents' mortgage and treating her family to a holiday.
In the interview she admitted having enjoyed a clandestine kiss with Spencer away from the watchful eye of the Big Brother cameras.
"We had a proper snog under an England flag in the garden. We felt like naughty schoolkids. It was a lovely kiss - the best one in the house," she said.