Which option best describes a passive solar orientation strategy?

• A. Active solar design with large PV array
• B. High thermal mass without orientation
• C. Uniform window placement
• D. Passive solar design with proper building orientation and shading

Answer: (D)

Passive solar orientation focuses on how a building is placed and shaded to use the sun for heating in winter and cooling in summer without relying on mechanical systems. The best description here is passive solar design with proper building orientation and shading because it directly links where the house sits and how its windows and shading devices manage solar heat. In practice, this means orienting most windows to capture winter sun from the south (in the Northern Hemisphere), using shading such as overhangs or trees to block high-angle summer sun, and sometimes incorporating thermal mass to store heat. This approach reduces the need for active heating and cooling by steering solar energy where it helps most.

The other options miss this integrated strategy: an active solar design with a large PV array focuses on generating electricity with equipment rather than using the building’s siting to regulate heat; high thermal mass without orientation won’t optimize heat gains or losses if the sun’s access is not controlled; uniform window placement ignores the seasonal sun path and the benefits of targeted exposure and shading.