Foreigners are returning, pushing government bond yields to levels not seen since before the economic downturn but most Spanish firms have stayed on the sidelines, concentrating on paying off their debts.
The 82-year-old Villar Mir, the chairman of builder OHL and its private conglomerate parent Grupo Villar Mir, prospered abroad during the crisis. With the economy growing at its strongest pace since 2007, he is now borrowing to fund acquisitions that may signal a new wave of investment in Spain.
"Spain is an investment opportunity now because things are cheap and the economy is recovering and hardly anyone has realised," the engineer told Reuters from a plush office near the top of his Torre Espacio, one of four landmark skyscrapers that dominate Madrid's skyline.
In January, he announced plans to sink 300 million euros into office-building owner Colonial in exchange for a planned 29 percent stake. The property firm is one of dozens that ran into trouble when Spain's building bubble burst in 2008, but its stock has soared 117 percent this year after Villar Mir backed a debt restructuring and recapitalisation.
He partly financed his Colonial stake with bank loans and said he aims for a 15 percent annual return on equity for all of his investments, including this one. That compares with an average financing cost of 7.7 percent, according to Moody's, down from a peak of 9.1 percent in 2011, but still four percentage points above Spain's 10-year benchmark bond.
Forbes estimates his net worth at $2.7 billion after he debuted last year on the magazine's global billionaires list.
A decision to exit Spanish housing in 2002 meant he skirted a spectacular crash which washed up hundreds of companies and banks -- although it also meant he missed an 80 percent gain in residential prices from 2002 to 2008. The tycoon says he is not expecting residential housing to recover for possibly another five years.
"Villar Mir has always had contrarian views. In 2002 OHL announced it was moving into concessions in Latin America, which seemed like a risky bet at the time given it is an emerging market where we had just had the Argentine crisis, and away from what at the time was seen as safe residential construction in Spain," said credit analyst Ivan Palacios, of Moody's.
"He has a record of identifying trends ahead of the rest."
Educated at Madrid's renowned El Pilar school, alma mater of premiers and business leaders, Villar Mir held senior administrative posts during the near-four decade Francisco Franco fascist dictatorship which followed the Spanish Civil War.
His office is full of photos with King Juan Carlos, who gave him the symbolic title of marquis in 2011 and signed him in for a brief tenure as treasury minister in 1975 after Franco's death.
His political connections became a liability last year, however, when he and seven other big contractors were questioned by a judge who was probing alleged illegal political donations.
The case, one of many revealed after the housing bubble burst, is ongoing.
Villar Mir, who recently named a former conservative minister as chief executive of OHL, denies wrongdoing.
"I like sailing in the summer, but I've never invited a politician to board my boat. Never," said the devout Catholic who installed a chapel in his Madrid office tower.
The engineer and lawyer began building his fortune after being asked in 1968 to help restructure electricity and chemicals company Hidro Nitro, and he developed a reputation for corporate turnarounds.
He has pounced on roughly one struggling company per year since he founded his eponymous group in 1987, with the purchase of troubled builder Obrascon for one peseta. It went on to become OHL, a 3.68 billion euro revenue giant whose projects include U.S. hospitals and high speed trains in Saudi Arabia.
During the crisis OHL - the Villar Mir Group's main asset by far - built up muscle abroad, boosting activity in transport concessions and scaling back construction. Now 92 percent of core earnings come from abroad, up from 70 percent in 2007.
Spanish private debt has fallen roughly 12 percent since a 2008 peak as families and companies tighten belts. But OHL's net debt has doubled in absolute terms in the same period.
The company has stuck to a strategy of re-leveraging assets aggressively to continually fund investments, and has a debt to core earnings ratio of 4.4 times, compared with an industry average of 1.65 times according to Thomson Reuters data.
OHL currently has 5.54 billion euros in net debt, up 32 pct in the last year.
Villar Mir's Colonial gambit followed another last year when he bought a century-old building in central Madrid for 225 million euros from Santander, nabbing it at near half the price of a previous deal which fell through for Spain's top bank.
"Santander said yes to me because they know I'll pay," Villar Mir said.
Santander itself provided the financing, and Villar Mir plans to team up with hotel chain Four Seasons to make it an exclusive shopping mall.
A few months after the deal he took a non-executive seat on the board of the bank which has been financing his business deals since the 1960s, and in which he holds stock.
Villar Mir has also backed the renewable energy sector, which ballooned during the boom years backed by state subsidies but suffered when the government reversed policy as it tried to save money.
Last year when the wind business was losing advocates, his group, also one of Spain's biggest private energy producers, announced a plan to reach 300 MWs of installed capacity in wind power by 2018, a reported 300 million euros investment to expand beyond its mainly hydro energy capacities.
Still, even after decades of business success, he has twice failed to win chairmanship of his beloved Real Madrid soccer club, the club of the city's political and business elite.