ENHANCEMENT OF HERITAGE BASED ON THE CANDIDACY OF GLOBAL HERITAGE STONE RESOURCE AND PROVINCE NOMINATION ON THE IBERIAN PENINSULA. CASE STUDY: THE PIEDRA BERROQUEÑA PROVINCE

Building stones give identity to towns and villages with their use. However social changes that encourage towns and cities to use stones from other regions for restoration and construction may lead to loss of heritage identity.

The nomination of Piedra Berroqueña as Global Heritage Stone Province and the Zarzalejo and Alpedrete granites as Global Heritage Stone Resource facilitates research into this issue. Both nominations can be widely used to interpret the heritage stone of the Iberian Peninsula.

There have been a series of actions aimed at the preservation of the building stones of Madrid. These actions involve local and international authorities: collaboration agreements with local government, workshops with local masons as well as scientific research.

There are several different municipal regulations in the Villages of Piedra Berroqueña Province, so the percentage of mandatory granite facades of buildings differs for every municipality. The protection of historic quarries also varies as it depends on rural land zoning for the extractive sector.

The quarries of origin and historical utilization have been studied. Local masons have provided granite samples oriented in accordance with the traditional cutting directions (rift, grain and hardway) and traditional carving. Petrophysical properties were also determined using techniques such as optical roughness, microhardness, ultrasonic velocity, air permeability, and microscopy. Finally durability has been studied at the Plaza Mayor in Madrid with the conclusion that the proper placement of granite in the building improves durability against deterioration processes.

Communication between the various interest groups involved in the conservation of heritage stones under the auspices of the Heritage Stone Task Group will assist co-ordination of heritage conservation between all stakeholders.