Electric power systems start with generation, where power plants use turbines driven by steam (from fossil fuels or nuclear reactions), flowing water, wind, or sunlight to produce three-phase AC electricity. This power is then stepped up by transformers and transmitted over long distances via high-voltage networks (overhead or underground) until it reaches substations. There, the voltage is stepped down for distribution.

At the consumer end, a single-phase lighting and power circuit is represented by a single-line diagram (or one-line schematic). This diagram shows the live (phase), neutral, and earth (ground) conductors, along with a switch, lamp load, and protective devices (such as a fuse or circuit breaker). It provides a standardized visual representation of electrical flow and safety measures.

Modern climate control relies on natural and mechanical ventilation to maintain indoor air quality. Natural ventilation utilizes airflow through windows, vents, or passive design, while mechanical ventilation employs fans and ducts to circulate air actively.

At the core of cooling systems lies the basic principle of refrigerant in air conditioning: a refrigerant absorbs heat from indoor air as it evaporates in the evaporator coil, then releases heat outdoors when compressed into a liquid in the condenser. This cycle repeats to regulate temperature.

Common systems include the split-unit air-conditioning system, where separate indoor (evaporator) and outdoor (condenser) units are connected by refrigerant lines, offering flexibility for small to medium spaces. In contrast, a centralized air-conditioning system uses a single chiller or rooftop unit to cool multiple zones via ductwork, ideal for large buildings with uniform cooling demands.

The fire triangle is the foundational model for understanding fire ignition and is critical for guiding extinguishing strategies. Fires are classified into different types, each requiring specific extinguishing agents.

Firefighting installations can be either portable or fixed, with the former suited for initial response and the latter providing continuous automatic suppression.

Finally, a robust fire alarm system integrates detection devices such as smoke, heat, or flame detectors along with manual pull stations, all connected to a central control panel. This system not only provides audible and visual alerts to occupants but also controls building systems and automatically notifies emergency services.

Plumbing systems ensure the safe delivery and disposal of water and waste. The hot and cold water supply network distributes potable water through pipes, valves, and storage tanks with cold water supplied directly from the mains and hot water delivered via water heaters to fixtures.

The sanitary system (or sanitary plumbing) collects wastewater from bathrooms and kitchens through an interconnected network of drains, traps, vent pipes, and soil stacks. This system then transports sewage either by gravity-fed or pressurized mechanisms to municipal sewers or septic tanks.

The solid waste collection system manages non-liquid refuse through dedicated refuse chutes or municipal collection services, serving as a critical element of integrated sanitation management.

Together, these three subsystems water supply, sanitary drainage, and waste removal form the foundation of modern building plumbing systems.

Lifts, escalators, and travelators serve as essential vertical and horizontal transportation systems in modern buildings. Lifts (elevators) facilitate vertical movement through hoist cables and motorized systems, efficiently optimizing space in high-rise structures. Escalators function as moving staircases, providing continuous passenger flow between different levels. Travelators (moving walkways) operate as flat conveyor systems, particularly useful in airports and long corridors to enhance pedestrian movement while reducing fatigue.

Intelligent buildings incorporate advanced automation and control systems that utilize centralized networks of sensors, controllers, and software. These integrated systems coordinate various building functions including air-conditioning, lighting, security, vertical transportation (lifts/escalators), and fire safety to achieve multiple benefits: improved energy efficiency, enhanced occupant comfort, superior safety standards, predictive maintenance capabilities, and optimized operational performance.

Through IoT connectivity and AI-powered analytics, these smart systems collect real-time data, enable seamless interoperability between subsystems, and automate responses based on factors such as occupancy patterns, environmental conditions, and building usage.