The party would remove the royal family from Buckingham Palace, but Green leader Natalie Bennett said she was "sure we can find a council house for her" as a result of their programme to build more.
Among their radical policies are the abolition of the monarchy, but Ms Bennett said the Queen would not be left homeless.
"I can't see that the Queen is ever going to be really poor, but I'm sure we can find a council house for her - we're going to build lots more," she said.
Ms Bennett hinted that the Greens would have a top rate of tax higher than 50p, with a wealth tax on multi-millionaires as part of a plan to "restructure society with the rich paying their way and multinationals paying taxes".
The party has benefited from a membership surge and the broadcasters have now invited Ms Bennett to take part in two televised debates ahead of the general election in recognition of its popularity - and David Cameron's insistence that the Greens be included following the decision to let Ukip's Nigel Farage take part.
Ms Bennett told The Times her party was attracting disaffected Labour supporters and "anti-Ukip voters".
She said: "People are really hungry for something different. There is an element of us being fresh and new, but we are also talking about ideas, optimism and changing things.
"We need to restructure society with the rich paying their way and multinationals paying taxes. People sometimes say to me, 'I saw you and I stopped shouting at the TV and throwing things at it. I finally agree with a politician'."
The Green leader defended her party's economic policies, despite critics' warnings, claiming that GDP was not as important as whether people had a "better quality life".
Asked whether she wanted the country to go into recession, she said: "It depends if you want to measure success by GDP. Even the people who invented GDP said it's a lousy tool for progress. The age of significant growth is over. We need to look at human measures now, not profits, but a better quality life."
She added: "We have been driven by this neoliberal Thatcherite idea that what motivates people is money. We want to focus on the fact that people don't just want to work to earn more and more, they want to do other things that often aren't recognised and valued."
Ms Bennett attacked "parasitical" global firms who did not pay tax and urged people to shop locally.
"These big multinationals are paying no taxes, making their staff work incredibly hard with no security on very little pay," she said.
"Meanwhile, they are using the resources that we pay for with our taxes. Amazon vans are using our roads to deliver, their workers are using our NHS to keep healthy, but the company isn't paying taxes to help ... they're parasitical."
The Greens would raise the minimum wage to £10 an hour, with a guaranteed £71 a week universal basic income, whether they were working or not.
"It would be a universal basic income from the state, children would get a bit less," she said. "There would be hardly any administration costs because it would go to every member of society. The assumption is that those of working age will top it up, but pensioners and the disabled will need extra help. It means that no one falls through the gaps."
Half of the £280 billion cost of the policy would come from tax, she indicated, with the rest made up of money already paid out in benefits like jobseekers' allowance.
"We are going to tax the rich more. In our last manifesto we had the top rate of tax at 50p for anyone earning over £100,000. I think it is going to be higher this time," she said.
There would also be a tax of 1% or 2% on people worth more than £3 million.
"People say to me that the rich will dodge it, but in some of the countries that already have it there is a simple rule that says if you haven't declared something on your wealth tax, you don't own it."
That would mean the state could "potentially" seize assets from the wealthy, she indicated.