Could this be the way Malta builds the future?

RE-STONE is a technology that was developed to reconstruct Maltese limestone and ultimately re-use and reduce the same construction waste, but things do not quite end there.



Re-Stone’s Public engagement presentation occurred today at Esplora. Ruums.eu was in attendance. Hon. Keith Azzopardi Tanti, Parliamentary Secretary for Youth, Research, and Innovation, spoke at the event.


Hon. Keith Azzopardi Tanti, Parliamentary Secretary for Youth, Research, and Innovation, spoke at the event.
Hon. Keith Azzopardi Tanti, Parliamentary Secretary for Youth, Research, and Innovation, spoke at the event.

Prof. Spiridione Buhagiar, Associate Professor in the Faculty of the Built Environment, and architect Franco Montesin directed the project, which stretched ten years of study and research, a further Thirteen student dissertations and a partnership with Halmann Vella, bridges the gap between academia and business.


Mr Clayton Cutajar, Esplora Director, Malta Council for Science and Technology, Prof. Spiridione Buhagiar, Project Coordinator, University of Malta Department of Civil and Structural Engineering, Perit Hugh Vella, Chief Commercial Officer Contracts, HalMann Vella were among the speakers. The Q&A session was moderated by Ms Sarah Gosh Roy, Science Communicator, Esplora, and further included Mr Andras Havasi, Corporate Research and Knowledge Transfer, the University of Malta together with Mr Stephen Borg, R&I Programmes Executive, Malta Council for Science and Technology.


limestone building blocks or excavated limestone material) into a viable and sustainable construction and decorative material. Re-Stone can also include concrete construction waste.

RE-STONE is a technology that was developed to reconstruct Maltese limestone and ultimately re-use and reduce the same construction waste, but things do not quite end there.


RE-STONE is a method that has been created to convert Maltese Globigerina limestone construction waste (mostly limestone building blocks or excavated limestone material) into a viable and sustainable construction and decorative material. Re-Stone can also include concrete construction waste.


Prof. Spirdione states, “Is this material being discarded a new resource?”

The resulting reconstituted stone material is a firm, dense limestone that can be cut, moulded, sculptured, and finished in the same way as the original limestone state while also having “twice the strength of a concrete block.” The colour of the regenerated globigerina is similar, if not identical, to the original.
The resulting reconstituted stone material is a firm, dense limestone that can be cut, moulded, sculptured, and finished in the same way as the original limestone state while also having “twice the strength of a concrete block.” The colour of the regenerated globigerina is similar, if not identical, to the original.

Currently, there is no solution for recycling building waste limestone and concrete that provides such significant benefits. The recycled material outperforms the original material in terms of strength, water resistance, and weathering. This blend may provide a solution to the construction sector’s issues, as Globigerina limestone is becoming increasingly scarce, and the construction industry generates the majority of the island’s waste. That’s the motivating factor behind the ReStone project, which aims to commercialise and render this material globally. The procedure entails acquiring waste limestone, building blocks, or excavation debris, crushing the waste, and then further processing the waste aggregate into an appropriately graded powder. After that, the powder is turned into a workable paste that may be moulded with binders. The finer the powder, the more durable the final product. The resulting reconstituted stone material is a firm, dense limestone that can be cut, moulded, sculptured, and finished in the same way as the original limestone state while also having “twice the strength of a concrete block.” The colour of the regenerated Globigerina is similar, if not identical, to the original. When mixed with concrete, the recycled Globigerina has grey tones. A percentage of construction waste can be converted into revenue-generating recycled building materials using this method. ‘Construction and demolition debris constitute one of the heaviest and most voluminous waste streams created in the EU,’ according to the European Commission. It accounts for between a quarter to a third of all waste created in the EU.’ Concrete and masonry make up 40-80% of the total. By 2020, the European Commission has set a goal for 70 per cent of waste materials to be recycled.


Given the usage of waste as raw material, the resulting products are expected to perform well in public-sector projects or those pursuing LEED certification. Building materials such as building blocks, bricks, cladding, tiles, and ornamental elements can all be made using this method. Because the procedure moulds the finished goods, specialised products containing water repellents, fire retardants, colour, fungicides, reinforcing, and other additives can be created.


The same material could be recycled up to four times, and at some stages of testing, the recycled material outperformed the original in terms of strength. “ We are interested in the durability and strength of the material” A patent application was filed in 2015, and it was eventually granted. To commercially manufacture the product, a new €5 million industrial facility is being designed and built.

A-Collective, a small architecture practice directed by Patricia Grech and Steven Risiott, took part in the Venice Biennale in 2021 with the project named, AKKA.



A-Collective, Venice Biennale, 2021, with the project named, AKKA, was constructed using Re-Stone.
A-Collective, Venice Biennale, 2021, with the project named, AKKA, was constructed using Re-Stone.

The material of choice for the installation was Re-Stone. In October of 2021, a ‘test’ room was built near the Ta Qali Crafts Village utilising recycled limestone blocks made from crushed recycled quarry waste. This structure is being observed to see how it responds as time passes, exposed to the elements. At this point, the research being conducted on this building is primarily based on aesthetics, but further assessments (VOC) and value research are being conducted.


The production of Re-Stone includes the utilisation of renewable energy and water reuse. The material will also help with project green credits. The project won second place in the Malta Intellectual Property Awards in 2020. We’re excited for Re-Stone to hit the market soon; reaction from government agencies and construction businesses has been good, and the product’s ability to be moulded opens up a world of aesthetic possibilities for interior and exterior solutions.



In October of 2021, a ‘test’ room was built near the Ta Qali Crafts Village utilising recycled limestone blocks made from crushed recycled quarry waste.
In October of 2021, a ‘test’ room was built near the Ta Qali Crafts Village utilising recycled limestone blocks made from crushed recycled quarry waste.



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