C5

Carbon Conversion Cycles: From Cultivation to Construction

C5 – Carbon Conversion Cycles From Cultivation to Construction (C2C)

About the Project

The C5 project pioneers an innovative Cultivation‑to‑Construction (C2C) model that connects rural biomass production with urban low‑carbon construction solutions. By linking agricultural feedstock cultivation (hemp, willow, agroforestry) with the creation of bio‑based building materials, C5 bridges two critical challenges facing Northwest Europe:

Rural regions face declining economic opportunities, soil pollution, and limited diversification.
Urban and peri‑urban areas struggle with the construction sector’s significant carbon footprint, which represents 5–12% of total greenhouse gas emissions.

C5 creates new circular economy value chains between these regions, transforming agricultural residues into construction‑ready materials and generating new income streams for farmers while reducing emissions in the built environment.

Project Objectives

C5 focuses on three transformative goals:

Pilot Innovative Carbon‑Based Cultivation Systems

Across seven regions, the project tests:

Hemp cultivation in nitrate‑sensitive areas
Willow and agroforestry production for high‑value fibre and structural uses
Phytoremediation cropping (DE, FR) on PFAS‑ and heavy‑metal‑polluted land
Biochar production using low‑value or contaminated biomass

These agricultural pilots feed directly into construction material production.

Develop Circular Construction Materials

C5 creates three “quality‑tiered” biomass‑to‑construction pathways:

These pathways are tested through pilots in DE, FR, BE, NL, and IE.

Build the C2C Strategy & European Cooperative Network

C5 will develop:

A C2C Strategy guiding regional adoption
Action Plans implemented in at least five NWE regions
A professional European Cooperative Society (SCE) to sustain and expand the model
A Recommender System supporting stakeholders in selecting the best cultivation‑to‑construction value chains for their region

Why It Matters

Rural Challenges

Many rural NWE regions face:

Soil contamination (PFAS, heavy metals, nitrates)
Low agricultural incomes and limited diversification
Declining soil health & biodiversity

C5’s cultivation systems offer:

New circular revenue streams
Soil remediation via phytoremediation
Opportunities for local farmers to enter emerging biomaterials markets

Urban Construction Challenges

The construction sector is responsible for:

High embodied carbon
High resource intensity
Low integration of bio‑based materials

C5 provides:

High‑performance, renewable material alternatives
Low‑carbon construction pathways
Regional supply chains linking rural production to urban demand

IrBEA’s Role in C5

IrBEA plays a central role as Ireland’s bioenergy and biomass expert within the C5 consortium. Its contributions focus on:

C5 stands out for its systemic, cross‑sector model:

Consolidates agricultural innovation and construction decarbonisation
Introduces three quality‑tiered pathways linking biomass to construction
Demonstrates Europe’s first integrated Cultivation → Conversion → Construction cycle
Tests applications of willow filaments and hemp fibres in new high‑value products
Introduces the first EU‑level C2C Cooperative Society (SCE) for long‑term replication
Utilises polluted land productively through phytoremediation crops
Deploys an innovative Recommender System helping regions select viable C2C value chains

Expected Impacts

By the end of the project, C5 will:

Establish six working regional C2C action plans
Produce multiple ready‑to‑market bio‑based construction products
Demonstrate three replicable C2C solutions
Support >50 professionals through training
Engage hundreds of stakeholders across agriculture and construction
Convert contaminated or degraded land into productive biomass sources
Reduce carbon emissions in both rural production and urban construction sectors
Launch a European Cooperative Society to sustain the model

Project Basics

Programme: Interreg North‑West Europe (NWE)
Priority: Transition to a place‑based circular economy
Objective: Circular & resource‑efficient economy (2.6)
Duration: 39 months
Budget: €4,000,000
Regions: Germany, France, Belgium, Netherlands, Ireland

Partners

A diverse group of research institutes, SMEs, public bodies, and sectoral organisations, including:

C5