What is a key feature of windows in energy-efficient houses?

The key feature of windows in energy-efficient houses is the use of full-length windows facing north for winter sun. This design approach allows for maximum natural light and passive solar heating during the colder months. In the winter, sunlight comes in at a lower angle, and northern exposure typically captures more of this sunlight throughout the day, helping to warm the interior of the home. This strategy reduces the need for artificial heating and can significantly lower energy costs.

In addition, large north-facing windows help maintain a comfortable indoor temperature by letting in warmth from the sun while minimizing the need for heating systems. It also supports good solar gain without the issues of overheating typical on the southern exposure during summer months. By strategically using this orientation, homeowners can take advantage of natural light and warmth, enhancing the energy efficiency of the house.