Havana (CNN) -- Olivia Sersute and her sister have shared the same home on the second floor of a faded Havana mansion since they were children and even after getting married and having kids of their own.
They didn't have much choice. In theory, Cubans own their own homes, but they aren't allowed to sell them.
"We're happy here," Sersute told CNN as she walked around the sparsely decorated apartment. "The problem is the kids. They're now in their 20s, and they want their own rooms. They want privacy."
Her family has started the long and bureaucratic process of a house "swap" -- the only legal option in Cuba for those who want to move.
That is about to change. This week, Cuba's National Assembly approved a plan to enact a new law permitting the sale of real estate, which was banned after Fidel Castro's 1959 revolution.
The legislation is expected to go into effect by the end of the year as part of a major overhaul of Cuba's stagnant economy.
Owners will need simple notary approval to buy or sell a home and will pay taxes on the transaction.
"You want to sell your house? You want to trade your house or donate it? The law will give you that right. You don't have to go to the Housing Department and ask permission of anyone," Marino Murillo, the government's point man on economic reforms, told the Assembly.
Many Cubans have already started to advertise their homes for sale on the website www.revolico.com, a kind of Cuban Craigslist that is often blocked on the island.
Cuba has a population of 11 million and a housing shortage of almost 500,000. It's not unusual to find three or even four generations crammed into a small apartment or divorced couples under the same roof.
In Havana, Cubans meet every Saturday for an improvised real estate market.
With pen and paper in hand, they peruse the notices nailed to trees and the stacks of handwritten descriptions carried by real estate "agents."
Although it is still illegal, plenty of money is paid under the table to balance out deals and to speed up the official bureaucracy. As many as six or seven properties can be involved in each tangled swap.
"In Cuba, we know how to live within the law and outside the law," said Angel Garcia, a middleman who helps buyers meet sellers.
Teresa is looking for a bigger place to move because her private bed and breakfast has taken off. She thinks the new law could make it easier.
"It will help get rid of the bureaucracy," she said.
President Raul Castro has said the accumulation of wealth will not be allowed.
Cubans can own only one home and Cuban Americans can send remittances to help relatives buy property, but they cannot have their name on the title.
Olivia Sersute says she and her sister will continue to look for two suitable apartments to trade their home for.
"All we've ever known is the 'swap,' " she said. "I don't have time to think about these modernizations, especially since they haven't happened yet."