But roofs — even half-missing ones — are a hot commodity these days in Havana, which has been swept by a bout of real estate fever. So Yoél Bacallao, a 35-year-old entrepreneur, offered to repair Ms. Martínez’s dilapidated house for free on one condition: that she let him build an apartment of his own on top of it. “It was as if a ray of light had come down from the sky,” said Ms. Martínez, 41, who would hang laundry in the roofless living room and sweep furiously during rainstorms to keep the rest of the house from flooding. “I have been watching this house fall apart around me for years.” All over the capital and in many provincial towns, Cubans are beginning to inject money into the island’s ragged real estate, spurred by government measures to stimulate construction and a new law that allows them to trade property for the first time in 50 years. The measures are President Raúl Castro’s biggest maneuver yet as he strives to get capital flowing on the island, encourage private enterprise and take pressure off the economically crippled state. For decades, the government banned real estate sales and kept a jealous grip on construction. Materials were scarce, red tape endless and inspectors meddlesome. Black marketeers would deliver cinder blocks by cover of darkness, and purchasing a bag of sand was a furtive process akin to buying drugs. But during the past two months the state has reduced paperwork, stocked construction stores, legalized private contractors and begun offering homeowners subsidies and credits. On many streets, the chip of hammers and gritty slosh of cement mixing rises above the sparse traffic as Cubans paint facades, build extensions or gut old houses. Still, it is generally small-scale stuff: Mr. Bacallao, who has savings from his business repairing mobile phones, expects to spend about $10,000 on his project. “Before, you had to sneak a bag of cement here, a bag of cement there,” he said. Mr. Bacallao, who rents a tiny apartment with his girlfriend, built a rooftop house three years ago, but the state confiscated it because he could not explain how he came by the materials. If this house works out, he will move his daughters to Havana from the provinces. “Now I can explain where I got the materials,” he said. “I can explain where I got the money. No problem.” Behind scruffy porticos and walls of bougainvillea, the wheels of the property trade are turning. Unofficial brokers — who are still outlawed in Cuba — say they have never been so busy, trawling the streets and the Internet for leads and fielding calls from prospective buyers. Cubisima, an online classified service, said the number of hits on its real estate page tripled to an average of 900 per day after the new property law took effect on Nov. 10. The law allows Cubans to buy and sell their houses, and even own a second home outside the cities, though it still bars most foreigners from buying. It is a crude market, where househunters rely on word of mouth and prices are based as much on excitement as on any clear sense of property values, according to interviews with homeowners, brokers and experts. Buyers, who at the top end are mainly Cuban émigrés and Cubans married to foreigners, often declare a fraction of what they pay, and money sometimes changes hands overseas, suggesting that the government’s hope of reaping significant tax revenues may be at least partly thwarted. On a recent day, a stylish flight attendant showed a viewer around the pretty three-bedroom home she hopes will fetch $150,000; a mile away, an elderly widow held out for an offer of $500,000 for her big, unkempt 1950s house — to be deposited in Spain, please. Many sellers plan to downsize, so they can live better or leave. Victoria Pérez, a retired doctor, put her spacious house and two-bedroom annex on sale last month for $80,000. She hopes to buy something smaller and put aside about $20,000 to live on and visit her daughter in the United States. “To earn $20,000 would take 20 years,” she said. “This opens up a whole world of opportunities.” Statistics are few, and brokers admit that the curious outnumber the serious. The National Housing Institute processed just 364 sales in the three weeks after the new law took effect.
