"You will always regret it if you do not buy now." The saying is so indelibly associated with real estate agents it might as well be branded on their foreheads. In Spain, it seems to have been very widely believed - at least until now.

Last year alone, Spain started to build 800,000 new homes, extending a construction bonanza that, along with low eurozone interest rates and putting a huge stock of un-employed labour to work, is one of the three pillars holding up Spain's high rate of economic growth.