NEST InGrained ecosystem foR zEro EmissioN buildings

Project Information

GreeNest

Grant agreement ID: 101138242

DOI

10.3030/101138242

EC signature date 18 December 2023

Start date 1 January 2024

End date 31 December 2027

Funded under

• Climate, Energy and Mobility

Total cost

€ 6 472 327,07

EU contribution

€ 4 996 642,01

Coordinated by

ETHNICON METSOVION POLYTECHNION
Greece

Periodic Reporting for period 1 - GreeNest (NEST InGrained ecosystem foR zEro EmissioN buildings)

Reporting period: 2024-01-01 to 2025-06-30

Summary of the context and overall objectives of the project

The building sector is a major contributor to greenhouse gas emissions, resource consumption and waste generation in Europe. While EU policies such as the recast Energy Performance of Buildings Directive (EPBD) increasingly address operational energy performance, achieving climate neutrality also requires reducing embodied emissions, supported by circular construction practices, digitalisation and locally embedded value chains.
The objective of the GreeNest project is to develop, demonstrate and prepare for market uptake an integrated ecosystem of solutions for Zero emission Buildings (ZeBs). The project combines bio-based and circular construction materials, digital design and assessment tools, inventory-driven design methodologies and regional value chains. GreeNest goes beyond conventional NZEB approaches by addressing the full building life cycle, including energy performance, embodied carbon, circularity, indoor environmental quality, productivity and social acceptance.
The pathway to impact is phased. In the first phase, GreeNest establishes regulatory, methodological and digital foundations, develops and prototypes innovative materials and systems, and validates ZeB solutions at design stage. Subsequent phases focus on implementation, demonstration and monitoring in real buildings across different European contexts, enabling measured validation and preparing replication and market uptake.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

By Month 18, GreeNest has delivered its core enabling frameworks, prototypes and design-stage validations, in line with the planned project phase.
A comprehensive regulatory and assessment framework has been established, including a harmonised KPI system covering operational energy use, greenhouse gas emissions, embodied carbon, circularity, indoor environmental quality, economic and societal aspects. This framework is consistently applied across all demonstration cases.
Inventory-driven and context-specific design methodologies, including DesignByInventory and DeltaSmart, have been operationalised and applied to all demo buildings. Through parametric simulations and KPI-based evaluation, multiple combinations of passive and active technologies were analysed and final ZeB solution sets were selected for each site. Design-stage results demonstrate that ZeB operational performance can be achieved compared to NZEB baselines.
The GreeNest ecosystem is structured around 17 Standardised Packages covering material innovations, envelope systems, energy systems, digital tools and construction processes. Key material packages include KARZ coffee-ground insulation, waste-wood structural elements, WDLT slab with earth screed, SmartWall and EcoTechWall systems, Heat Harvest and Reversible Windows, and Light Clay prefabricated earth modules. Energy and building services packages include advanced photovoltaic systems and heat-pump-based heating, cooling and storage. Digital and process packages include the ASSESS decision-support tool, NestControls monitoring and automation system, GreeNest BIM Database, BIM Suite and digital twin environment, and circular construction and value-chain integration methods.
Several packages, notably KARZ, Light Clay, SmartWall and EcoTechWall, have been developed and prototyped, representing concrete exploitable results addressing embodied carbon reduction and circularity.
A fully operational digital ecosystem has been established, enabling structured data exchange, integration of Standardised Packages and preparation for real-time monitoring. The NestControls system has been developed and tested in a sandbox environment, providing readiness for energy, comfort and indoor air quality monitoring.
The ecosystem is validated through four demonstration cases: the Berlin Museum Pavilion (Germany), the Athens Sandbox Building (Greece), the Delta Info Center in Porto Viro (Italy), and the North Aegean Youth Recreational Center (Greece). Each demo applies a tailored combination of packages selected through KPI-based assessment, demonstrating adaptability and replicability across climates, building types and local value chains.
Societal and skills-related impacts have been initiated through Living Lab activities, hands-on workshops and training, particularly focused on circular construction and Light Clay techniques.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

GreeNest advances beyond the state of the art by moving from isolated technology improvements to an integrated ZeB ecosystem. It combines bio-based and circular materials with digital design, assessment and monitoring tools, enabling simultaneous optimisation of operational and embodied performance. Material innovations such as KARZ and Light Clay valorise waste streams, enable local production and reduce embodied emissions while maintaining high thermal performance.
At system level, the integration of Standardised Packages within inventory-driven design methodologies enables adaptation to local climatic, regulatory and market conditions without re-engineering. At process level, digital workflows, prefabrication-oriented planning and local value chains prepare the ground for future productivity gains.
At Month 18, most core results are positioned between TRL 4 and TRL 6, consistent with the project timeline. Design methodologies, digital tools and KPI frameworks are operational, while material innovations and monitoring systems are at prototype or pre-demonstration level. Progression to higher TRLs will occur through on-site implementation, monitoring and validation.

GreeNesT: Construction with lightweight clay bricks

GreeNest leaflet

GreeNest:Livinglab- Sanbox for demosntration of the ecosystem

GreeNest: Visualization of the Zero Emission Demo Case in Berlin

GreeNest: Chair made out of coffeebean-waste

GreeNest rollup