What is an example of a "green building" feature that can lower operational costs?

A renewable energy system is a prime example of a "green building" feature that can significantly lower operational costs. These systems, such as solar panels or wind turbines, generate energy from natural and replenishable resources. By harnessing energy from the sun or wind, buildings can reduce their reliance on grid electricity, leading to lower utility bills over time. In addition to providing cost savings, renewable energy systems can also contribute to sustainability goals by reducing greenhouse gas emissions and promoting energy independence.

The other options, while relevant in certain contexts, do not provide the same level of cost-effective sustainability. High water consumption fixtures would typically increase operational costs by wasting resources. Single-pane windows tend to have poor insulation properties, leading to higher energy usage for heating and cooling. Conventional HVAC systems may lack efficiency compared to more modern, energy-efficient systems, resulting in potentially higher operational costs.