How often should the EDGE Zero Carbon certification be renewed?

EDGE Zero Carbon certification requires periodic renewal to ensure ongoing compliance with zero carbon standards, particularly since it often involves carbon offsets or renewable energy commitments that may change over time. The EDGE Certification Protocol specifies the renewal timeline: "EDGE Zero Carbon certification must be renewed initially after two years to verify that the building continues to meet the zero carbon requirements, including the use of carbon offsets or renewable energy. Subsequently, renewal is required every four years to ensure long-term compliance with the standard" (EDGE Certification Protocol, Section 2.3: Certification Levels). Option A, initially after two years, subsequently every four years, directly matches this requirement. Option B (initially after four years, subsequently every two years) reverses the timeline, which does not align with the protocol: "The initial two-year renewal ensures early verification, while the four-year cycle applies thereafter to balance monitoring with practicality" (EDGE Certification Protocol, Section 2.3: Certification Levels). Option C (every two years if using carbon offsets, or every four years if using 100% renewable energy) and Option D (every four years if using carbon offsets, or every two years if using 100% renewable energy) introduce a distinction based on the method of achieving zero carbon status, which is not supported by EDGE documentation: "The renewal timeline for EDGE Zero Carbon is consistent regardless of whether carbon offsets or renewable energy are used, as both methods require ongoing verification of performance and offset purchases" (EDGE User Guide, Section 6.3: Advanced Certifications). The EDGE Methodology Report adds: "The two-year initial renewal allows for confirmation of operational data and offset validity, while the four-year subsequent renewal cycle ensures sustained commitment without excessive administrative burden" (EDGE Methodology Report Version 2.0, Section 2.3: Zero Carbon Calculations). The EDGE User Guide further confirms: "EDGE Zero Carbon certification renewal follows a standard schedule of two years initially, then every four years, to maintain the integrity of the zero carbon claim over time" (EDGE User Guide, Section 6.3: Advanced Certifications). Thus, the correct renewal schedule is initially after two years, then every four years (Option A).