Constructed Soil
Carbon Systems
THS v1.0 - Annex N
Constructed Soil Carbon Systems engineers designed soil substrates - precisely blended combinations of mineral aggregates, organic amendments, biochar, and structural materials - on land where natural soil is absent, severely degraded, or being purpose-built, such as reclaimed mine sites, brownfield redevelopment, or engineered green infrastructure. Rather than working with an existing soil and amending it, this pathway builds a soil system from its constituent components specifically designed to maximise long-term carbon retention alongside its primary function (vegetation support, stormwater management, or land reclamation).
How this pathway works
Some land has no functioning soil to amend - former mine sites stripped of topsoil, industrial brownfield redevelopment, or newly constructed green infrastructure like engineered rain gardens or green roofs - requiring an entirely built soil profile rather than the amendment of an existing one. Constructed Soil Carbon Systems designs this substrate deliberately, blending mineral components (for structure and drainage), biochar (for long-term carbon stability and water retention), and organic matter (for nutrient cycling and initial vegetation establishment) in specified ratios validated to maximise carbon retention over the system's design life.
Under the Teravent Hybrid Carbon Standard (THS v1.0) Annex N, this pathway is classified as hybrid because the carbon benefit results directly from the engineered substrate design - unlike passive soil restoration, the composition and structure of the constructed soil is a deliberate technology intervention distinct from allowing natural soil formation processes to occur. Teravent Hybrid Credits (THC) are issued for verified net tonnes of CO₂-equivalent sequestered in the constructed soil profile, net of full lifecycle project emissions.
THS v1.0 - Annex N
This pathway is governed exclusively by the Teravent Hybrid Carbon Standard (THS v1.0). No external registry, standard, or methodology is referenced or incorporated.
Two approved methodology variants
THS v1.0 Annex N approves two methodology types, differentiated by site context and substrate design.
Former mine sites, quarries, and other severely degraded land often lack any functional topsoil after extraction activity strips or destroys the original soil profile. This methodology builds a complete replacement soil system - blending overburden material, mineral amendments, biochar, and compost or other organic matter in carefully validated ratios - designed both to support vegetation re-establishment and to maximise long-term carbon retention within the reconstructed profile.
- Substrate composition documented at construction - mineral, biochar, and organic matter ratios
- Periodic soil core sampling confirming carbon pool stability and composition over time
- Contaminated site screening and remediation documentation prior to construction
- Vegetation establishment and cover monitoring as a co-benefit and erosion-stability indicator
Urban green infrastructure - rain gardens, bioswales, structural soil cells supporting street trees, and green roof substrates - requires precisely engineered soil media to meet drainage, load-bearing, and vegetation support specifications simultaneously. This methodology credits the carbon retention benefit of substrate designs that incorporate biochar or other stable carbon amendments into these already-required engineered soil systems, capturing additional climate value from infrastructure being built regardless for stormwater or urban greening purposes.
- Substrate composition documented at installation, meeting both engineering and carbon retention specifications
- Periodic soil sampling at accessible representative locations confirming composition stability
- Stormwater management or urban heat mitigation performance tracked as co-benefit indicators
- Infrastructure maintenance records confirming the substrate has not been disturbed or replaced
Which emission sources must be counted
Measurement, reporting
& verification
Substrate composition - the mineral, biochar, and organic matter ratio - is precisely documented at construction, since this is a designed rather than naturally occurring soil system, giving very high initial confidence. Long-term stability is confirmed through periodic soil core sampling at representative locations, verifying the carbon pool has not degraded or eroded. Where biochar forms a substantial fraction of the substrate, the standard H/Corg stability protocol is applied to confirm Class II eligibility.
Demonstrating additionality
Leakage types & deductions
Buffer pool & NPRR assessment
| Methodology | Durability Class | Buffer Pool Rate | Primary Reversal Risks |
|---|---|---|---|
| CSC-M01 Reclaimed Land | Class I–II (by composition) | 7–40% | Erosion; substrate disturbance during further site development |
| CSC-M02 Urban Green Infrastructure | Class I–II (by composition) | 10–35% | Infrastructure replacement or excavation ahead of design life |
Key registration criteria
Sustainable Development
Goal alignment
Deployment scope: Global - regions with legacy mining and industrial land requiring reclamation, and cities investing in engineered green infrastructure for stormwater management and urban greening.
Ready to register your
constructed soil project?
Submit a Project Concept Note under THS v1.0 Annex N to begin your registration. Select the CSC-M code matching your site context, validate your substrate design, and appoint an accredited VVB to validate your PDD.