Energy Use Intensity (EUI) is a widely used metric to measure the energy efficiency of a building. It is calculated by dividing the total energy consumption of the building by its floor area and is typically expressed in kilowatt-hours per square meter per year (kWh/m²/yr).

The primary objective of a building energy audit is to identify energy-saving opportunities. This involves analyzing the building's energy consumption, identifying areas of inefficiency, and recommending measures to improve energy performance.

All of the options listed are common energy efficiency measures implemented in buildings. Installing energy-efficient lighting, upgrading to a more efficient HVAC system, and improving insulation levels can all contribute to reducing energy consumption and improving the energy efficiency of a building.

Measurement and Verification (M&V) is the process of verifying the actual energy savings achieved by an energy efficiency measure. It involves collecting data on energy consumption before and after the implementation of the measure and comparing the results to determine the actual energy savings.

When evaluating the cost-effectiveness of an energy efficiency measure, it is important to consider all of the relevant factors, including the initial cost, the energy savings, and the maintenance costs. The measure should be evaluated over its entire lifespan to determine its true cost-effectiveness.

Retro-commissioning is the process of optimizing the performance of an existing building's mechanical and electrical systems. It involves reviewing the systems, identifying areas for improvement, and implementing measures to improve their efficiency.

All of the options listed are common energy efficiency measures implemented in lighting systems. Installing energy-efficient light bulbs, using occupancy sensors to control lighting, and implementing daylight harvesting strategies can all contribute to reducing energy consumption and improving the energy efficiency of a building's lighting system.

A Net Zero Energy Building is a building that produces as much energy as it consumes. This can be achieved through a combination of energy efficiency measures and renewable energy generation.

All of the options listed are common energy efficiency measures implemented in HVAC systems. Installing a programmable thermostat, upgrading to a more efficient HVAC system, and improving insulation levels around HVAC ducts can all contribute to reducing energy consumption and improving the energy efficiency of a building's HVAC system.

All of the options listed are terms used to describe a building that is designed to minimize its environmental impact. Green buildings, sustainable buildings, and LEED Certified buildings are all designed to be energy-efficient, resource-efficient, and environmentally friendly.

All of the options listed are common energy efficiency measures implemented in building envelopes. Improving insulation levels, installing energy-efficient windows and doors, and applying reflective coatings to the roof can all contribute to reducing energy consumption and improving the energy efficiency of a building's envelope.

An Off-Grid Building is a building that is designed to be energy-independent. This means that it generates all of its own energy needs, typically through renewable energy sources such as solar or wind power.

All of the options listed are common energy efficiency measures implemented in water heating systems. Installing a low-flow showerhead, upgrading to a more efficient water heater, and insulating hot water pipes can all contribute to reducing energy consumption and improving the energy efficiency of a building's water heating system.

All of the options listed are terms used to describe a building that is designed to be highly energy-efficient and environmentally friendly. Green buildings, sustainable buildings, and LEED Certified buildings are all designed to minimize their environmental impact and promote energy efficiency.

All of the options listed are common energy efficiency measures implemented in appliances. Using energy-efficient appliances, unplugging appliances when not in use, and using power strips to control multiple appliances can all contribute to reducing energy consumption and improving the energy efficiency of a building's appliances.