A nine point finding by Transparency International has found that corruption over building projects in Spain was mainly responsible for the rise in house prices. The report also concluded that local town halls were becoming riddled with corruption as a result of building projects, citing the case of Mallorca, where several towns have modified some 227 times their different urbanisation plans. The report also states that an enormous amount of 'black money' is involved in the construction business, and as a result the loss in taxes for the Finance Ministry is said to be "very considerable."

The report by professor Manuel Villoria of the King Juan Carlos University in Madrid, states that the scandal unleashed by Catalan president Pascual Maragall when he stated that the region's former CiU government was demanding 3% kickbacks from construction companies "was the tip of the iceberg," and that "the depth of the problem is not individual acts of corruption, rather a form of institutionalised corruption aimed at obtaining illicit funds for various political parties. This is the new form of cancer that the government should try and stop."