What is the CDM-SSC-PDD?

The project design document (PDD) is the key document involved in the validation and registration of a CDM project activity. It is one of the three documents required for a CDM project to be registered, along with the validation report from the designated operational entity (DOE) and the letter of approval from the designated national authority (DNA).

The PDD is reviewed by the DOE during the validation process to ensure that a project meets the requirements for validation. The PDD is also used as the basis of consultation with stakeholders, which is conducted by making the PDD and related documentation publicly available on the UNFCCC website.

The project design document is then included in the request for registration which is submitted by the DOE to the Executive Board.

Specific PDDs exist for different project types:

  • Standard CDM project activities (CDM-PDD)
  • Small-scale project activities (CDM-SSC-PDD)
  • Afforestation and reforestation project activities (CDM-AR-PDD)
  • Small-Scale afforestation and reforestation project activities (CDM-SSC-AR-PDD)
  • Programmes of Activities (POA-DD) and CDM Programme Activities (POA-CPA-DD)

This section discusses the requirements of the PDD for small-scale CDM project activities (CDM-SSC-PDD). The latest version of the CDM-SSC-PDD is contained in EB 28, Annex 34.  This document is Version 3 of the CDM-SSC-PDD and replaces Version 2 contained in EB 23, Annex 26 and Version 1 in EB 7 Annex 5.

The Executive Board has clarified that a small-scale project that generates emission reductions from more than one type of activity, and which therefore relies on more than one methodology, can be registered using a single CDM-SSC-PDD:

The Board agreed that a project activity with more than one component may submit one PDD, provided the information regarding the sections covering the type and categories and technology/measure of the SSC project activity and application of the baseline and monitoring methodology in the CDM-PDD are provided separately for each component (EB 28, paragraph 57).

Requirement to develop a CDM-SSC-PDD

The requirement to develop a PDD for small-scale projects is set out in 4/CMP.1, Annex II, paragraph 13:

Project participants shall prepare a project design document in accordance with the format specified in appendix A to this annex (4/CMP.1, Annex II, paragraph 13).

Content of the CDM-SSC-PDD

The same decision sets out the information that must be included a PDD (including a CDM-SSC-PDD).  In summary, the CDM-SSC-PDD must:

  • Describe the project and establish a project boundary;
  • Describe the baseline methodology;
  • Establish the duration and crediting period of the project;
  • Describe how the project is additional;
  • Describe the environmental impacts of the project;
  • Provide information on the sources of public funding for the project;
  • Summarise stakeholder comments;
  • Describe the monitoring plan; and
  • Set out all relevant calculations.

This chapter will deal with all of these issues as they are implemented in the project design document for small-scale projects (CDM-SSC-PDD).

The content required in the CDM-SSC-PDD is set out in full in 4/CMP.1, Annex, Appendix B, paragraph 2:

A project activity shall be described in detail taking into account the provisions of the annex on modalities and procedures for a CDM, in particular, section G on validation and registration and section H on monitoring, in a project design document which shall include the following:

  1. A description of the project comprising the project purpose, a technical description of the project, including how technology will be transferred, if any, and a description and justification of the project boundary;
  2. A proposed baseline methodology in accordance with the annex on modalities and procedures for a CDM including, in the case of the:
    1. Application of an approved methodology:
      • Statement of which approved methodology has been selected;
      • Description of how the approved methodology will be applied in the context of the project;
    2. Application of a new methodology:
      • Description of the baseline methodology and justification of choice, including an assessment of strengths and weaknesses of the methodology;
      • Description of key parameters, data sources and assumptions used in the baseline estimate, and assessment of uncertainties;
      • Projections of baseline emissions;
      • Description of how the baseline methodology addresses potential leakage;
    3. Other considerations, such as a description of how national and/or sectoral policies and circumstances have been taken into account and an explanation of how the baseline was established in a transparent and conservative manner;
  3. Statement of the estimated operational lifetime of the project and which crediting period was selected;
  4. Description of how the anthropogenic emissions of greenhouse gases by sources are reduced below those that would have occurred in the absence of the registered CDM project activity;
  5. Environmental impacts:
    1. Documentation on the analysis of the environmental impacts, including transboundary impacts;
    2. If impacts are considered significant by the project participants or the host Party: conclusions and all references to support documentation of an environmental impact assessment that has been undertaken in accordance with the procedures as required by the host Party;
  6. Information on sources of public funding for the project activity from Parties included in Annex I which shall provide an affirmation that such funding does not result in a diversion of official development assistance and is separate from and is not counted towards the financial obligations of those Parties;
  7. Stakeholder comments, including a brief description of the process, a summary of the comments received, and a report on how due account was taken of any comments received;
  8. Monitoring plan:
    1. Identification of data needs and data quality with regard to accuracy, comparability, completeness and validity;
    2. Methodologies to be used for data collection and monitoring including quality assurance and quality control provisions for monitoring, collecting and reporting;
    3. In the case of a new monitoring methodology, provide a description of the methodology, including an assessment of strengths and weaknesses of the methodology and whether or not it has been applied successfully elsewhere;
  9. Calculations:
    1. Description of formulae used to calculate and estimate anthropogenic emissions by sources of greenhouse gases of the CDM project activity within the project boundary;
    2. Description of formulae used to calculate and to project leakage, defined as: the net change of anthropogenic emissions by sources of greenhouse gases which occurs outside the CDM project activity boundary, and that is measurable and attributable to the CDM project activity;
    3. The sum of (i) and (ii) above representing the CDM project activity emissions;
    4. Description of formulae used to calculate and to project the anthropogenic emissions by sources of greenhouse gases of the baseline;
    5. Description of formulae used to calculate and to project leakage;
    6. The sum of (iv) and (v) above representing the baseline emissions;
    7. Difference between (vi) and (iii) above representing the emission reductions of the CDM project activity;
  10. References to support the above, if any (3/CMP.1, Annex, Appendix B, paragraph 2).


The Executive Board introduced General guidelines for sampling and surveys for small-scale CDM project activities at its 50th meeting (EB 50, Annex 30). PDDs utilising sampling for determination of parameter values to calculate emission reductions are to include a sampling plan describing the sampling approach, important assumptions, and the justification for selecting the chosen approach (EB 50, Annex 30, para 2). These guidelines set out procedures, sampling application guidance, and sampling plan documentation.
Further guidance has been given by the Executive Board on the level of detail required to be included in a PDD:
The Board considered recommendations by the Meth Panel and agreed that the specific uncertainty levels, methods and associated accuracy level of measurement instruments and calibration procedures to be used for various parameters and variables should be identified in the PDD, along with detailed quality assurance and quality control procedures. In addition standards recommended shall either be national or international standards. The verification of the authenticity of the uncertainty levels and instruments are to be undertaken by the DOE during the verification stage (EB 23, paragraph 24).

Related Topics

What is a baseline? (SSC)

What is additionality? (SSC)

What is a methodology? (SSC)

What is a letter of approval? (SSC)

Designated operational entity (DOE)


Project boundary (SSC)

Crediting period (SSC)

Large-scale PDD (CDM-PDD)

Forestry PDD (CDM-AR-PDD)

Small-scale forestry PDD (CDM-SSC-AR-PDD)

Programme of Activities Design Document (CDM-POA-PDD)

CDM Programme Activity Design Document (CDM-CPA-PDD)