Which of the following is a passive design strategy to reduce energy use in buildings?

• A. Orientation and shading to control solar gain
• B. High-performance HVAC system
• C. Photovoltaic panels
• D. Water-efficient fixtures

Answer: (A)

Passive design uses the building itself to regulate heat, daylight, and comfort with little or no mechanical systems. Orientation and shading are classic examples because they rely on how the sun moves across the sky and how architectural elements interact with that movement to control heat gain.

By positioning the building to take advantage of winter sun and using shading devices like overhangs, fins, or louvers, you allow warmth to enter when it helps and block it when it would cause overheating. This reduces the need for cooling in hot seasons and limits heating requirements in cooler times, cutting energy use without relying on powered equipment. It’s a naturally occurring effect that continues to work as the building’s environment changes, making it a fundamental passive strategy.

In contrast, a high-performance HVAC system, while effective at lowering energy use, depends on active energy from the grid to condition spaces. Photovoltaic panels generate electricity rather than reduce demand through the building’s design; they offset energy use but aren’t passive in the sense of shaping the building’s thermal performance. Water-efficient fixtures mainly reduce water use and the energy tied to heating that water, but they don’t directly manage heat flow or daylight through the building.