In the CBCI EDGE curriculum, a "required" measure refers to a measure that must be implemented in the project as part of meeting the EDGE certification criteria. Required measures are mandatory and cannot be excluded if the project is to achieve certification. Their implementation is verified during the design audit and confirmed during the site audit stage.
Option A is incorrect because simply assessing a measure is not sufficient; a required measure must be physically incorporated into the building design and construction. Option C is incorrect because a Special Ruling Request is used in exceptional cases to seek clarification or alternative compliance pathways, but required measures do not depend on SRR approval to be implemented. Option D is also incorrect because the concept of meeting or exceeding the baseline relates to performance calculations for savings, not specifically to the definition of a required measure.
Therefore, under the EDGE framework, a required measure is one that must be implemented in the project to comply with certification requirements, making option B the correct answer.

Variable Refrigerant Volume (VRV) or Variable Refrigerant Flow (VRF) systems are evaluated in EDGE for their energy efficiency in HVAC applications. The EDGE User Guide explains their application: "VRV/VRF systems are best suited for multizone spaces, as they can simultaneously heat and cool different zones by varying the refrigerant flow, making them ideal for buildings with diverse thermal loads, such as hotels, offices, or hospitals with multiple rooms" (EDGE User Guide, Section 4.2: Energy Efficiency Measures).
Option C, multizone space, aligns with this description, as VRV/VRF systems excel in managing varied temperature needs across multiple zones. Option A (single zone space) and Option B (single zone office space) are incorrect, as VRV/VRF systems are less efficient for single zones: "For single zone spaces, simpler systems like split units are more appropriate, as VRV/VRF systems are designed for multizone control" (EDGE Methodology Report Version 2.0, Section 5.1: Energy Efficiency Metrics). Option D (meeting space) is too specific and typically a single zone, not leveraging VRV/VRF's multizone capability: "Meeting spaces are often single zones, where VRV/VRF systems may be oversized" (EDGE User Guide, Section 4.2: Energy Efficiency Measures). Thus, VRV/VRF systems are best used for multizone spaces (Option C).
Reference: EDGE User Guide Version 2.1, Section 4.2: Energy Efficiency Measures; EDGE Methodology Report Version 2.0, Section 5.1: Energy Efficiency Metrics.

In a hot and dry climate with low rainfall, water efficiency measures in EDGE are evaluated based on their potential to reduce potable water demand, but their effectiveness depends on local conditions. The EDGE User Guide explains the impact of various water-saving measures: "In regions with low rainfall, rainwater harvesting provides minimal water savings due to limited precipitation, whereas measures like low-flow showers, dual flush toilets, and black water recycling can achieve consistent savings by reducing direct water use or reusing wastewater" (EDGE User Guide, Section 5.2: Water Efficiency Measures). Option B, rainwater harvesting, relies on rainfall to collect water for non-potable uses, but in a hot and dry climate with low water availability, its effectiveness is limited: "Rainwater harvesting systems in EDGE are modeled based on local precipitation data. In arid climates with annual rainfall below 200 mm, savings from rainwater harvesting are typically less than 5% of total water demand, as the collected volume is insufficient to meet significant needs" (EDGE Methodology Report Version 2.0, Section 4.2: Water Savings Calculations). In contrast, Option A (low-flow showers) reduces water use directly: "Low-flow showers can reduce water consumption by 20-30% in buildings, regardless of climate, by limiting flow rates to 6-8 liters per minute" (EDGE User Guide, Section
5.2: Water Efficiency Measures). Option C (recycle black water) also offers consistent savings: "Black water recycling systems can save 30-40% of water demand by treating and reusing wastewater for flushing or irrigation, independent of rainfall" (EDGE Methodology Report Version 2.0, Section 4.2: Water Savings Calculations). Option D (dual flush for water closets) similarly provides reliable savings: "Dual flush toilets reduce water use by 25-35% by offering a low-flush option for liquid waste, effective in all climates" (EDGE User Guide, Section 5.2: Water Efficiency Measures). Given the low rainfall in a hot and dry climate, rainwater harvesting (Option B) yields the lowest water savings compared to the other measures, which do not depend on precipitation. The EDGE User Guide further notes: "In dry climates, measures like rainwater harvesting are often the least effective, while demand-side measures (e.g., low-flow fixtures) and recycling systems provide higher and more consistent water savings" (EDGE User Guide, Section 5.3: Additional Water Efficiency Measures). Thus, rainwater harvesting (Option B) gives the lowest water savings in this context.
Reference:EDGE User Guide Version 2.1, Section 5.2: Water Efficiency Measures, Section 5.3: Additional Water Efficiency Measures; EDGE Methodology Report Version 2.0, Section 4.2: Water Savings Calculations.

Air-cooled chillers are a type of HVAC system commonly evaluated in EDGE for their energy efficiency in green building design. The EDGE Methodology Report Version 2.0 outlines the components of air-cooled chillers in the context of energy efficiency measures. According to the EDGE User Guide (Version 2.1), air- cooled chillers differ from water-cooled chillers by not requiring a cooling tower or associated water-based components like a condenser pump. The guide states: "Air-cooled chillers consist of a compressor, air-cooled condenser, thermal expansion valve, and evaporator, which work together to provide cooling by rejecting heat directly to the ambient air" (EDGE User Guide, Section 4.2: Energy Efficiency Measures). Option A includes a cooling tower and condenser pump, which are specific to water-cooled chillers. Option D mentions a water- cooled condenser, which is incorrect for air-cooled systems. Option C includes a chilled water pump, which is not a core component of the chiller itself but part of the broader system. Option B accurately lists the compressor, condenser (air-cooled, implied), thermal expansion valve, and evaporator, aligning with the EDGE description of air-cooled chiller components.
Reference:EDGE User Guide Version 2.1, Section 4.2: Energy Efficiency Measures; EDGE Methodology Report Version 2.0, HVAC Systems.

Efficiency in fans and pumps is a critical aspect of green building design in EDGE, particularly for reducing energy consumption in HVAC systems. The EDGE User Guide provides detailed guidance on efficiency measures for mechanical systems: "Variable speed drives (VSDs) deliver the highest efficiency in fans and pumps by adjusting the motor speed to match the actual demand, significantly reducing energy consumption compared to fixed-speed systems. VSDs can achieve energy savings of up to 30-50% in HVAC applications by avoiding the constant operation at full speed typical of single or constant speed drives" (EDGE User Guide, Section 4.2: Energy Efficiency Measures). Option D, variable speed drive, aligns with this description as the most efficient option. Option A (two speed drive) offers some efficiency by allowing two operating speeds, but it is less flexible than VSDs: "Two speed drives provide limited efficiency gains, as they cannot continuously adjust to varying loads, unlike variable speed drives" (EDGE Methodology Report Version 2.0, Section 5.1: Energy Efficiency Metrics). Option B (single speed drive) and Option C (constant speed drive) are essentially the same in this context, operating at a fixed speed regardless of demand, leading to energy waste: "Single speed or constant speed drives run at a fixed rate, resulting in higher energy consumption compared to variable speed drives, which modulate speed based on need" (EDGE User Guide, Section 4.2:
Energy Efficiency Measures). The EDGE Methodology Report further elaborates: "Variable speed drives are the most efficient option for fans and pumps in EDGE, as they minimize energy use by matching output to demand, unlike two speed or constant speed drives, which operate inefficiently under partial loads" (EDGE Methodology Report Version 2.0, Section 5.1: Energy Efficiency Metrics). This makes variable speed drives (Option D) the clear choice for delivering the highest efficiency in fans and pumps.
Reference:EDGE User Guide Version 2.1, Section 4.2: Energy Efficiency Measures; EDGE Methodology Report Version 2.0, Section 5.1: Energy Efficiency Metrics.