Global Construction C-Sink Standard
The Global Construction C-Sink Standard: How buildings can store biogenic carbon long-term
The Global Construction C-Sink Standard verifies buildings and civil engineering works that contain biomass-derived Carbon Sink (C-Sink) Materials. The biomass contains biogenic carbon, which is based on the fact that CO2 was previously actively removed from the atmosphere. This biomass, examples of which include hemp, straw, wood or biochar, is incorporated into the building and thus represents a carbon sink. Each verified construction is considered a C-Sink Unit and can be registered in our publicly available Global C-Sink Registry if all GHG emissions that were caused by the production and transportation of the embedded Construction C-Sink Materials were offset.
The Global Construction C-Sink Standard includes guidelines for rigorous tracking of biomass-derived carbon from biomass production to the construction site, accounting for greenhouse gas (GHG) emissions for all processing steps in the production of Construction C-Sink Materials (i.e., GHG expenditures) and registering the construction lifecycle. The present standard ensures that every unit of carbon sequestered within the construction materials is trackable through endorsed digital monitoring, reporting, and verification (dMRV) systems. The Construction C-Sink Standard guarantees the highest quality because it meets key market requirements:
The Construction C-Sink Standard guarantees the highest quality because it meets key market requirements
- Immediate impact – Carbon is stored from day one
- Scalable – Available in volumes sufficient for global markets
- Traceable – Every C-sink is precisely located and verifiable within the building
- Long term carbon storage – Storage is maintained over the lifetime of a construction, often beyond
The first verified building – by Openly
The Construction C-Sink Standard was developed in collaboration with Ithaka Institute for Carbon Strategies and Openly Systems and can be widely applied in the construction industry.
Here you will find the current version of our standard.
Global Construction C-Sink, digital monitoring and documentation.
OPENLY has received endorsement as a Global Construction C-Sink Manager. The first pilot project in Widnau was certified according to the Global Construction C-Sink Standard and demonstrates what climate-friendly construction can look like today. Watch the video on our blog. (2025)
This milestone represents an important step toward integrating carbon storage into the construction sector and demonstrates how buildings can actively contribute to achieving net-zero emissions.
Additional projects are currently undergoing the validation and verification process and will soon expand the growing portfolio of certified buildings.
Find a list of IT Tools applicable to the Global Construction C-Sink Standard here:
As an endorsed C-Sink Manager, you will be able to manage and certify buildings and infrastructure.
The Construction C-Sink Manager training program consists of two days of training at the OPENLY Academy and concludes with official certification.
The steps on this path to official certification and the acquisition of C-Sinks are as follows:
- Schedule a First-Call
- Register for the Construction C-Sink Manager program using the registration form
- Attend the 2-day training course at the OPENLY Academy
- You can now independently prepare the first construction project for validation and certification
- The audit and endorsement for C-Sink Manager is conducted by CSI – annual renewal
- Calculation and verification of the first construction project
- Issuance of the corresponding certificates and public registration in the Global C-Sink Registry
- Utilization of the C-Sink for insetting or transfer If you are interested in becoming a Construction C-Sink Manager or would like to register and certify a construction project with our partners according to our Global Construction C-Sink Standard, book a First-Call here.
This section is currently being updated.
This section is currently being updated.
Ongoing public consultation As part of the validation process, the projects needs to go through a public consultation, where third-parties can provide feedback.
You can find all projects under public consultation in our Global C-Sink Registry, marked with the status “Ongoing Validation”.
If you would like to have Carbon Standards review potential modifications or amendments to the standard, please review the following:
Standard updates
Here you find the old version of the standards including a marked version with the changes to the current version of the Global Construction C-Sink Standard.
Contact person
Robin Werren
PM Global Construction C-Sink
+41 (0) 62 552 10 86
robin.werren@carbon-standards.com