EDGE EDGE-Expert - Excellence in Design for Greater Efficiencies (EDGE Expert) Exam

Within the CBCI EDGE curriculum, greywater is defined as relatively low-contamination wastewater generated from bathing and handwashing activities, typically coming from fixtures such as showers, wash basins, and bathtubs. This type of wastewater is considered suitable for recovery and reuse in certain non-potable applications, depending on local codes and the treatment approach, because it does not contain toilet waste.

A water closet WC produces blackwater, not greywater. Blackwater contains fecal matter and urine and therefore has a much higher pathogen load and organic content. Because of this, it requires more stringent treatment processes and different health and safety controls compared with greywater systems. In EDGE water measures, greywater reuse calculations and strategies are based on sources like showers and hand basins, while toilet discharge is excluded from greywater source assumptions.

Therefore, among the listed fixtures, the one that does not produce greywater in EDGE is the water closet WC, making option D the correct answer.

The EDGE certification process involves specific steps and fees, including a registration fee, to formally enter a project into the certification system. The EDGE Certification Protocol outlines the timing of the registration fee: "The registration fee must be paid prior to registration of the project in the EDGE system. This fee is required to activate the project in the EDGE App, allowing the Client to begin the self-assessment process and proceed toward certification" (EDGE Certification Protocol, Section 2.1: Registration). Option B, prior to registration, directly matches this requirement, as payment is a prerequisite for starting the certification process. Option A (prior to site audit) is incorrect, as the site audit occurs later, at the post-construction stage: "The site audit takes place after practical completion, well after registration, so the registration fee is not tied to this stage" (EDGE Certification Protocol, Section 3.4: Post-Construction Requirements). Option C (after the registration) is also incorrect, as payment must precede registration: "Registration cannot be completed without payment of the registration fee, ensuring the project is officially entered into the system" (EDGE User Guide, Section 6.1: Project Preparation). Option D (after certification has been awarded) is wrong, as certification occurs at the end of the process, after registration and audits: "Certification fees may be paid after certification, but the registration fee is required at the outset, before any assessment begins" (EDGE Certification Protocol, Section 3.3: Certification Decision). The EDGE User Guide further clarifies: "Paying the registration fee prior to registration ensures that the project is formally recognized by the EDGE system, enabling access to the software and certification resources" (EDGE User Guide, Section 6.1: Project Preparation). Thus, the registration fee must be paid prior to registration (Option B).

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).

According to the CBCI EDGE curriculum, the EDGE software calculates and reports building energy performance based on delivered energy consumption. Delivered energy refers to the actual energy supplied to the building from external sources such as electricity from the grid, natural gas, district cooling, or other fuels. The software estimates annual energy use for both the baseline case and the improved case and expresses savings as a percentage reduction in delivered energy.

EDGE does not primarily report results in terms of primary energy, which would include upstream energy losses associated with extraction, generation, and transmission. While primary energy is a common metric in some building assessment systems, EDGE focuses on delivered energy because it is directly measurable, easier to verify, and more applicable across diverse markets globally.

Electrical energy alone is also not the sole output, since buildings may use multiple energy carriers such as gas or district systems. Renewable energy is considered within the improved case when on-site systems such as solar photovoltaics are included, but it is not itself the energy consumption result; rather, it offsets delivered energy demand. Therefore, the correct answer is delivered energy.

According to the CBCI EDGE certification procedures, certain measures require physical verification and performance testing during the site audit to confirm that installed systems match the design-stage commitments entered in the EDGE software. Low-flow faucets for bathrooms fall into this category because their compliance depends on measurable flow rates. During the audit, the EDGE Auditor may use flow-measuring devices to test fixture discharge rates and verify that they meet the specified liters per minute used in the improved case calculations. This ensures that projected water savings are genuinely achieved in practice.

In contrast, measures such as a green roof are typically verified visually and through documentation such as drawings and material specifications rather than performance testing. Condensate water recovery and wastewater treatment systems are usually confirmed through installed system inspection, capacity checks, and documentation review, but not necessarily through direct flow-rate testing at each fixture point like low-flow faucets. The curriculum emphasizes that fixtures with defined performance parameters, such as flow rates, are subject to on-site testing to maintain the integrity and credibility of EDGE water savings claims.

Within the EDGE framework, “waste heat recovery” from generators refers to capturing usable thermal energy from engine jacket water and exhaust gases that would otherwise be rejected to the environment. This recovered heat is a thermal resource, so it can directly serve end uses that require heat, such as space heating and domestic hot water heating. The curriculum also recognizes that recovered heat can indirectly support space cooling when it drives thermally activated cooling technologies, such as absorption chillers, where heat is used as the driving input to produce chilled water.

Mechanical ventilation, however, is fundamentally different. It is primarily an electrical end use because it relies on fans and motors to move air through ducts and provide required air changes. Thermal energy from recovered waste heat cannot power fan motors in the way electricity does. While waste heat might temper ventilation air through heat exchangers, that is not the same as being an energy source for the ventilation system itself. EDGE distinguishes between thermal end uses and electrical fan energy, so generator waste heat cannot be counted as a source of energy for mechanical ventilation.

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In the CBCI EDGE curriculum, the embodied carbon assessment for existing buildings is handled differently from new construction. The key principle is that the existing building fabric is treated as already “sunk” and is not counted again in the embodied carbon calculation. This means elements such as the existing roof construction do not increase embodied carbon in the EDGE assessment for a retrofit project, because EDGE focuses on what is newly added or replaced as part of the upgrade scope.

Embodied carbon in EDGE is driven by the quantities and types of new construction materials introduced through the retrofit, such as added insulation, new wall or roof layers, new glazing, new finishes, or other building-material interventions. Therefore, the factor that increases embodied carbon is the inclusion of new materials in the retrofit scope.

While external shading devices can indeed add embodied carbon because they are additional materials, the most accurate and complete statement in the options is the broader one: any new materials added during the retrofit increase embodied carbon. New mechanical systems are generally treated under operational energy impacts rather than being core contributors in the EDGE embodied carbon in materials calculation.

According to the CBCI EDGE curriculum, when entering plumbing fixture data into the EDGE software, the value required is the actual flow rate of the fixture in liters per minute, not the product code, price, or any other specification number shown in supplier documentation.

From the specification image, the overhead shower is described as having a single flow rate of 6 liters per minute. Other numbers visible in the specification, such as 1,315 or 3,590, represent product codes or pricing information, not water flow rates. The 4 liters per minute value in the image applies to a wall mixer component and not to the shower head itself.

In EDGE, water savings for showers are calculated based on the flow rate combined with default usage assumptions. Therefore, the correct value to input for a low-flow shower head is its rated flow in liters per minute. Since the overhead shower shown has a flow rate of 6 liters per minute, that is the value that should be entered into the EDGE software.

Accurate entry of fixture flow rates is essential because it directly affects the calculated percentage reduction in water consumption compared to the baseline case.

Embodied carbon in EDGE refers to the carbon emissions associated with the production, transportation, and installation of building materials, a key metric for materials efficiency. The EDGE User Guide specifies how this is measured: "In the EDGE software, the embodied carbon of materials is quantified in kilograms of carbon dioxide equivalent (kgCO2), reflecting the total greenhouse gas emissions associated with the material’s lifecycle, from extraction to installation" (EDGE User Guide, Section 7.2: Materials Efficiency Measures). Option A, kgCO2, directly matches this unit, as EDGE uses kgCO2 to standardize carbon emissions across materials, allowing for comparison and aggregation in the software’s results. Option B (MJ) is incorrect, as MJ (megajoules) measures embodied energy, not carbon: "Embodied energy in EDGE is measured in MJ, representing the energy consumed in material production, while embodied carbon is separately calculated in kgCO2 to assess environmental impact" (EDGE Methodology Report Version 2.0, Section 6.1: Embodied Energy in Materials). Option C (BTU) is also incorrect, as BTU (British Thermal Units) is an energy unit not used in EDGE for carbon calculations: "EDGE uses metric units like MJ for energy and kgCO2 for carbon; BTU is not a standard unit in the software" (EDGE User Guide, Section 2.3: Using the EDGE App). Option D (kWh) is another energy unit, typically used for operational energy, not embodied carbon: "kWh is used in EDGE to measure operational energy consumption, such as electricity use, but not for embodied carbon, which is always in kgCO2" (EDGE Methodology Report Version 2.0, Section 5.2: Energy Calculation Methods). The EDGE User Guide further clarifies: "The software displays embodied carbon in kgCO2 to align with global carbon accounting standards, enabling users to understand the environmental footprint of their material choices" (EDGE User Guide, Section 7.2: Materials Efficiency Measures). The EDGE Methodology Report adds: "For example, concrete might have an embodied carbon of 0.15 kgCO2 per kg, allowing users to compare materials like fly ash concrete versus standard concrete in terms of carbon impact" (EDGE Methodology Report Version 2.0, Section 6.1: Embodied Energy in Materials). Thus, the unit of embodied carbon in EDGE is kgCO2 (Option A).