Eligibility and scope

Eligible technologies

Projects are eligible for removal Rainbow Carbon Credits (RCCs) under this methodology, with durabilities of 35, 50, 75 or 100+ years. Eligible removals are from the incorporation of biomass-derived biogenic carbon into long-lived construction products and buildings.

Eligibility and requirements are defined at three levels: the biobased product, building element, and the building.

Category	Description	Example
Biobased product	A construction product containing biomass and its associated biogenic carbon.	Timber, hempcrete, cellulose (loose or in blocks).
Building element	A component of a building, composed of construction products. To be eligible under this methodology, it must include at least a fraction of biobased products.	Foundations, insulation (composite panel), structural frames.
Building	A long-lived roofed construction with a fixed foundation and load-bearing walls, designed for a long-term structural service life, and which can be categorized based on its intended purpose and form. To be eligible under this methodology, it must include at least a fraction of eligible building elements.	Individual house, apartment building, office building, parking garage.

Two types of projects are eligible, with the following eligibility requirements:

	Biobased Product Use in Buildings	Biobased Product Manufacturing
Project mitigation activity	Construction or renovation of one or more buildings or other long-lived structures within the built environment, that include biobased materials	Production of a single biobased product or building element
Eligible building elements	Foundations Basement elements Structural frames, slabs and panels (situated above ground floor slab, including roof structure)	Any building element that is not listed in the Biobased Product Use in Buildings eligible elements and is long-lived with low replacement rates in buildings, including but not limited to: Insulation Road components
Project Developer	Either the building developer, the building owner, or a third-party contractually assigned responsibility for monitoring, liability for post-crediting monitoring, and ownership of RCCs.	The manufacturer of biobased products
Geographic scope	All eligible buildings or structures in the same country.	All eligible biobased products manufactured by one registered company within a single country.
Basis for credit issuance	Foundations: RCCs issued upon proof of completed delivery of foundation via an official certificate issued by a third party. All other building elements: RCCs issued upon proof of completed building construction, proven via the issuance of the building permit.	RCCs issued according to the amount of biobased products delivered to building developers during the monitoring period. Project Developers must track the biobased product all the way to its delivery at a construction site for use in a building or structure.

Certification requirements

Crediting period duration

Projects certified under this methodology shall have a maximum crediting period duration of 5 years, which can be renewed for a total of 20 years. Upon reaching the maximum duration, a project's crediting period may be renewed, according to the Crediting Period Renewal procedure.

Monitoring period duration

The default monitoring period duration is one year, but may be a different length at the Project Developer's request. Project Developers shall submit a Monitoring Report at least once per 24 months. Failure to do so shall result in the project being deregistered.

Post-crediting monitoring period

The post-crediting monitoring period for Biobased Product Use in Buildings shall be the entire duration of the durability claim (e.g. 35 years for 35-year durability claims, 100 years for 100 year claims...). The post-crediting monitoring period begins for each building upon issuance of its corresponding RCCs. See the Durability section for more details.

Site audits

Validation site audits for projects under this methodology may be performed remotely. They shall follow the requirements outlined in the Rainbow Procedures Manual.

Versioning and project compliance

When this methodology is revised, projects may continue under the previous methodology version used for their initial validation for subsequent verifications of RCCs. However, Project Developers should update their projects to comply with the latest requirements whenever possible.

Project scope

For both project types, the project scope is cradle-to-handover. This includes the manufacture, transport, and onsite construction steps, for only the biobased products within eligible building elements. This corresponds to the A1-A5 modules in the Environmental Product Declaration (EPD) framework.

The use and end-of-life stages are excluded from the comparative GHG quantification because they are required to be equivalent between the project and baseline scenarios. This corresponds to the B and C modules in the Environmental Product Declaration (EPD) framework.

For all projects, the project scope excludes:

• carbon storage from packaging,

• non-eligible biobased products and building elements, and

• use-stage removals from mineral carbonation.

Baseline scope

Biobased construction materials and buildings must be valid substitutes for the construction material chosen for the baseline scenario, regarding performance metrics and delivered functions.

An activity-specific baseline shall be used based on the individual project scope. This baseline shall be set conservatively, according to historical or current market conditions of the substituted construction material used in the absence of the project. Detailed instructions for defining the baseline are provided below, for each project type (Biobased Product Manufacturing and Biobased Product Use in Buildings).

The baseline scenario structure remains valid for the entire crediting period but may be significantly revised earlier if:

• The Project Developer notifies Rainbow of a substantial change in project operations or baseline conditions, and/or

• The methodology is revised, affecting the baseline scenario.

The specific values within the baseline scenario will be updated during each crediting period, using project data to accurately reflect the equivalent of the project’s operations.

Biobased Product Manufacturing

Project Developers shall justify how the project's biobased material substitutes the baseline material according to the following characteristics: function of the product, reference service lifetime, performance, and price/quality.

• Performance indicators vary by material type, but may include insulation capacity, load bearing capacity, or compressive strength.

• Sources for this criteria may include performance tests, dynamic thermal studies, secondary reports, scientific literature, and EPDs.

If the durability or the performance of the primary function of the project biobased material is different from the baseline material, this must be accounted for in the baseline scenario and project scenario selection. For example, if the project biobased product has a weaker performance than the baseline material, a larger quantity of the project material may be required to attain the same performance/function as the baseline material.

Biobased Product Use in Buildings

An activity-specific baseline shall be used that represents a building or portfolio of buildings with the same overall design and building elements as the project, but using business-as-usual construction products instead of eligible biobased products.

Project Developers shall justify that the chosen baseline building elements and biobased products are representative of the project scenario and conservative, with reference to the following characteristics: overall building design (e.g. useful floor area, internal partitions, and building envelope geometry), function of the building elements, expected service lifetime of the building, performance, and price/quality.

If multiple buildings share the same construction typology, a shared baseline typology may be defined. The typology defines the material breakdown, and the baseline removals for any individual building shall be calculated by applying the typology to the actual floor area or geometry of that building. See the GHG quantification Baseline scenario section for examples and details.

If the activity-specific baseline assessment identifies no eligible biobased construction products used, the activity-specific baseline shall be set to zero.