Background Natural stone production has many related environmental problems, including very low energy efficiency and productivity, the generation of huge amounts of waste, and non-optimised use of natural resources. The impact and significance of these problems become apparent when one considers that to produce 190 m2 of stone tiles, corresponding to the average floor area of a modern house, it is necessary to quarry 100 tonnes of natural stone. Overall production efficiency, therefore, is only 7%. The main reasons for this are the high proportion of blocks and slabs that are unsuitable or destroyed during saving and cutting, because of internal defects, fractures and cracks; the low speed of drilling and cutting equipment, meaning that stone production is a long process with high energy consumption; and loss of useful stone during cutting because of the thickness of the cutting tools. Objectives The main objective of the project was the implementation, dissemination and promotion of a sustainable system to enhance the production and use of natural stone. This utilised the best available techniques and products, to produce an ECO-STONE (or sustainable stone). The project focused on three main aspects: optimisation of use of natural sources and raw materials, optimisation of energy consumption in the production chain, and use of new multifunctional natural stone based materials with good energy and environmental efficiency. Results The ECO-STONE project demonstrated the possibility of reducing energy consumption during the production of natural stone, therefore obtaining a more energy efficient final product. This was done through the manufacture of a thinner cutting disc, new consolidation techniques for blocks and slabs, innovative materials based on natural stone with multifunctional properties (e.g. thermal storage capacity and self-cleaning properties), and the characterisation of the natural stone production chain, namely in terms of energy consumption. The project introduced a number of innovative technologies and materials. The new system for stone cutting involved the modification of a conventional cutting disc according to software simulation results. The new disc was manufactured with a reduced thickness, which reduces energy consumption, production times and the amount of stone waste, and therefore increases productivity. New consolidation techniques were introduced to reduce breakages. The project utilised consolidation agents based on water-borne resins, as well as new methodologies for natural stone impregnation, to increase the cohesion of fractured blocks and slabs. This increases the durability of natural stone, reduces maintenance work after their placing and reduces the emission of pollutants into the atmosphere. Innovative materials were used, based on natural stone with multifunctional properties. The project team incorporated Phase Change Materials (PCMs) to different types of natural stone to demonstrate the efficiency of PCMs as energy storage materials. PCMs reduce thermal fluctuations between day and night, delay the time to reach maximum or minimum temperature, and protect natural stone in extreme climatic conditions. They also have self-cleaning properties (so dirt can easily be removed), which increases the durability of natural stone and gives a higher uniformity in façades. The materials implemented by the project have not previously been applied in the production of construction materials made of stone. The coordinating beneficiary AIDICO worked with companies (LASMAR in Spain, LEVANTINA in France and CEVALOR in Greece) to obtain more information about the thin cutting disc, PCMs and self-cleaning technologies. The technologies developed by the project team can be transferred to other companies in the natural stone sector worldwide, with appropriate adaptions to local conditions. The potential for transfer of the project is high, and it benefits both quarries and processing plants. Uptake of the ECO-STONE approach brings a range of environmental benefits, including a reduction in energy consumption during natural stone production (with a reduction in equivalent CO2 production), lower amounts of residues, a reduction in the emission of pollutants (e.g. VOCs), and improvements in air quality and therefore human health. The technologies and materials developed by the project can help transform a traditional and regionalised stone sector into a modern, competitive, and sustainable industry. In economic terms, for instance, the cutting operations performed with the thinner cutting disc consumed 4.86% less energy than those executed with a conventional disc, while the incorporation of PCMs to natural stone materials reduced energy consumption, due to their energy storage properties (e.g. cooling energy for a reference wall/24h is 508.5 kJ/m2 compared to 367.1 kJ/m2 for a wall with a PCM layer). The approach is expected to increase manufacturing efficiency from 7% to around 16%. In social terms, ECO-STONE could lead to improvements in life quality, as buildings become more comfortable due to a reduction in temperature fluctuations between day and night as a result of using natural materials combined with PCMs. Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).