GBCI EDGE EDGE-Expert Book

The purpose of EDGE, as defined by the International Finance Corporation (IFC), is to make green building accessible and scalable, particularly in emerging markets. The EDGE User Guide states: "EDGE was created by IFC to promote a simple and scalable platform for green buildings, enabling developers to achieve resource efficiency in new constructions through a user-friendly tool that focuses on energy, water, and materials savings" (EDGE User Guide, Section 1.1: Introduction to EDGE). Option C, a simple and scalable platform for green buildings, directly aligns with this mission. Option A (revenue for green building champions) is incorrect, as EDGE’s goal is not financial gain for individuals but broader market transformation: "EDGE aims to transform the building sector, not to generate revenue for specific stakeholders" (EDGE Certification Protocol, Section 1.1: Overview). Option B (few exemplary high-performance buildings) contradicts EDGE’s scalability focus: "EDGE is not about creating a few high-performance buildings but enabling widespread adoption of green practices" (EDGE User Guide, Section 1.1: Introduction to EDGE). Option D (highly accurate prediction of resource consumption) is also incorrect, as EDGE prioritizes simplicity over precision: "EDGE uses simplified calculations for resource consumption, not highly accurate predictions, to ensure accessibility" (EDGE Methodology Report Version 2.0, Section 2.1: Calculation Approach). Thus, EDGE promotes a simple and scalable platform (Option C).

The design certification stage (Preliminary Certification) in EDGE requires specific actions from the Client to ensure the project can be audited and certified. The EDGE Certification Protocol outlines the process: "To complete the design certification stage, the EDGE Client must provide the EDGE Auditor with access to the completed self-assessment in the EDGE software, along with all supporting documentation, such as drawings, specifications, and calculations, to verify the selected measures" (EDGE Certification Protocol, Section 3.1: Certification Process). Option C, provide the EDGE Auditor access to the self-assessment and all supporting documentation, matches this requirement. Option A (internally review the EDGE measures) is a preparatory step, not a certification requirement: "Internal reviews are recommended but not mandated for certification" (EDGE User Guide, Section 6.1: Project Preparation). Option B (access the EDGE software and complete a self-assessment) is a prerequisite to the audit, not the final step for design certification: "The self-assessment must be completed before the audit, but certification requires submission to the Auditor" (EDGE Certification Protocol, Section 3.1: Certification Process). Option D (sign an agreement with a certification partner) is incorrect, as this is typically handled during project registration, not design certification: "Agreements with Certification Providers are signed prior to registration, not at the design stage" (EDGE Certification Protocol, Section 2.1: Registration). Thus, providing the Auditor access (Option C) is the required action.

In EDGE, the Coefficient of Performance (COP) is used to measure the efficiency of heating systems that produce heat using a refrigeration cycle, such as heat pumps. The EDGE Methodology Report specifies: "The Coefficient of Performance (COP) is used in EDGE to evaluate the efficiency of heat pumps, including ground source heat pumps, where it is defined as the ratio of thermal output to electrical input. This metric is not applied to direct heating systems like electric heaters or boilers" (EDGE Methodology Report Version 2.0, Section 5.1: Energy Efficiency Metrics). Option C, ground source heat pump, fits this description as it operates using a refrigeration cycle to transfer heat, and its efficiency is measured by COP in EDGE. Option A (electric heater) has an efficiency typically measured as 100% (or COP of 1), but EDGE does not use COP for such systems, as noted: "Electric heaters are assumed to have a fixed efficiency in EDGE, not evaluated via COP" (EDGE User Guide, Section 4.2: Energy Efficiency Measures). Option B (condensing boiler) uses thermal efficiency (%), not COP, as per: "Boilers in EDGE are assessed by their thermal efficiency, not COP" (EDGE Methodology Report Version 2.0, Section 5.2: Heating Systems). Option D (sensible heat recovery from exhaust air) is a heat recovery method, not a heating system, and does not use COP: "Heat recovery systems are evaluated by their heat recovery effectiveness, not COP" (EDGE User Guide, Section 4.3: Ventilation Measures). Thus, ground source heat pump (Option C) is the correct choice.

In EDGE, measures are evaluated for their impact on energy, water, and embodied energy in materials, the three core pillars of the standard. For an air-conditioned hospital with a water-cooled chiller, the measure must affect all three areas to be the correct answer. The EDGE User Guide provides detailed descriptions of each measure’s impact: "Variable speed drive (VSD) pumps in HVAC systems, such as those used in water-cooled chillers, impact energy by reducing electricity consumption through load modulation, water by optimizing the chiller’s cooling water circulation (reducing water use in the cooling tower), and materials because their installation may involve additional components with embodied energy, such as the VSD unit itself" (EDGE User Guide, Section 4.2: Energy Efficiency Measures). Option C, variable speed drive pumps, thus impacts all three areas: energy (reduced electricity use), water (less cooling tower water loss), and materials (embodied energy in the VSD equipment). Option A (insulation of the roof) affects energy (reduced cooling load) and materials (embodied energy in insulation), but not water: "Roof insulation reduces energy demand but does not directly impact water consumption" (EDGE User Guide, Section 4.1: Insulation Measures). Option B (water-efficient urinals) impacts water (reduced consumption) and potentially materials (embodied energy in fixtures), but not energy: "Water-efficient urinals save water but have no direct energy impact in EDGE calculations" (EDGE User Guide, Section 5.2: Water Efficiency Measures). Option D (water-efficient dishwashers) also affects water and materials, but not energy in this context: "Water-efficient dishwashers reduce water use, but their energy impact is minimal unless they include hot water savings, which is not specified for hospital dishwashers in EDGE” (EDGE Methodology Report Version 2.0, Section 4.2: Water Savings Calculations). The EDGE Methodology Report further confirms: "VSD pumps in water-cooled chillers are unique in affecting all three EDGE metrics—energy through efficiency, water through reduced cooling tower evaporation, and materials through the embodied energy of the equipment" (EDGE Methodology Report Version 2.0, Section 5.1: Energy Efficiency Metrics). Thus, variable speed drive pumps (Option C) is the measure impacting energy, water, and materials.