The Global Construction C-Sink Standard: How buildings can store biogenic carbon long-term

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. All buildings that contain biomass-derived materials such as wood, hemp, straw, biochar and many others can be verified.

These valuable C-sinks are of the highest quality because they are secure, geo-localized and bound within the building for its entire lifetime.

The projects are implemented by our endorsed Construction C-Sink manager Openly Systems (contact).  

The Global Construction C-Sink Validation and Verification System.

If 20 % of the anthropogenic material could be replaced by biomass-derived materials and recycled carbon, around 400 gigatons of CO₂e could be removed from the atmosphere and transferred to carbon sinks over the next 20 years, which is roughly half of the negative emissions required to keep global warming below 1.5°C (UNFCCC, 2015), given that GHG emissions were curbed to 10 % by 2050 (Smith et al., 2024).

Biomass and anthropogenic mass estimates since the beginning of the twentieth century on a dry-mass basis following Elhacham et al., 2020.

Even if only a very feasible 10 % of the construction materials would be replaced by Construction C-Sink Materials, a very significant C-Sink increase of 200 Gt CO₂e could be achieved. For this reason, there is an urgent need for a certification standard for construction-related carbon sinks (C-Sinks), which is provided for the first time in the novel Global Construction C-Sink Standard presented here.

The Construction C-Sink Tool was developed for builders and Construction C-Sink managers. It can be used to manage, verify and validate C-Sink materials as well as buildings and constructions (C-Sink Units). After verification, C-Sink Units can be transferred to the Global C-Sink Registry.

While fossil CO₂ emissions are significantly warming the Earth's atmosphere, reliable carbon sinks (C-sinks) are cooling the planet, leading to a global cooling effect. The Global Construction C-Sink Standard ensures that its global cooling effect is correctly calculated and publicly registered. The mandatory tracking system guarantees the integrity and transparent quantification of the C-sinks and their time-dependent climate effects. 

Global Construction C-Sink, digital monitoring and documentation.

Recycling construction materials is both an integral part of circular economies and crucial in determining the long-term fate of the carbon embodied in the C-Sink Materials. Thus, the possible recycling scenarios of construction materials are considered in the certification and registration procedures, ensuring that its global cooling potential is correctly calculated and publicly registered. 

The validation and verification of a carbon sink includes all elements that have arisen during its construction. It thus not only includes the calculation of the global cooling effect of the carbon sink, but also the assessment and compensation of all emissions that have arisen during the construction of the carbon sink. The lifecycle of the construction must be estimated and compared to the average lifecycle of the same type of construction. Based on this assessment, the technical audit defines the monitoring method and controlling period of the Construction C-Sink.

A building usually represents a secure carbon sink for at least 60 years.

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 old version of the standards including a marked version with the changes to the current version of the Global Construction C-Sink Standard.