Recycled and Natural Materials and Products to develop nearly zero energy buildings with low carbon footprint


The main objective of the project is to demonstrate and promote solutions for buildings with nearly zero energy needs through the incorporation of natural and/or recycled components and, therefore, contribute to reducing the energy or carbon footprint associated with buildings.



Since 35% of the EU's greenhouse gases emissions are linked to constructing and living in buildings, there is high demand for the development of more energy efficient building methods and more environmentally sustainable building materials. The LIFE ReNaturalNZEB project will show that components made from natural and recycled substances can reduce both the cost and carbon footprint of new and renovated buildings. In addition to reducing greenhouse gases embodied in building materials by 60%, the new lightweight structures can reduce internal energy demand by up to 80%. As part of the project, 10 technology prototypes will be built and tested onsite in Portugal and Spain.



  • To develop a construction model of nearly zero energy low-cost building with low carbon footprint using green and circular economy criteria.
  • To introduce sustainable construction materials and technologies "close to the market" such as kenaf insulation, rice husk composite materials and biomass ash in concrete structure.
  • To promote sustainable construction technologies with low market rate in Spain and Portugal such as wood structure, windows and finishes, compressed earth block structure, cork insulation, olive kernel biomass, clay wall panels and sustainable green roof/façade.
  • To build 10 prototypes (2000 m²) in existent and new constructions with natural and recycled technologies selected in the project.
  • To produce technical documentation, regulations, recommendations and urban regulations for renovation of buildings to promote the use of construction technologies based on recycled and materials and reduce embodied energy in construction.
  • To decrease the environmental impact of buildings, through the use of recycled and natural materials.
  • To decrease the energy demand in buildings using envelopes that incorporate recycled and natural materials.
  • To disseminate the proposed technologies.
  • To promote nearly zero energy buildings implementation in Portugal and Spain.



  • Characterization of building technologies incorporating recycled and natural materials
  • Low-carbon footprint NZEB modelling and design
  • Low-carbon footprint NZEB demo cases experiments
  • Labelling, legislation and plans for low-carbon construction
  • Monitoring
  • Dissemination and training in the construction sector



  • Installation, in new and renovated buildings, of 10 prototypes of technologies based on natural and recycled materials;
  • Reduction of the CO2 emissions (by 60%) in the construction and renovation of 10 pilot buildings;
  • Reduction of the energy demand in buildings in Portugal and Spain from 100 to 20 kWh/m² per year;
  • Cutting of construction waste in half, compared to Portuguese and Spanish standards;
  • Creation of 10 works related to the development and adoption of green technologies;
  • Training of 1,500 professionals and 500 construction workers towards the design and construction of NZEB buildings;
  • Approval of regulations on the use of natural and recycled materials in the construction sector;
  • Carrying out of three environmental and economic studies on the feasibility of using technologies based on natural and recycled materials in the construction sector;
  • Organization of seminars, workshops and specialized courses to produce guidelines for the public to raise awareness of the use of technologies based on natural and recycled materials in the construction sector.