1. Identify and measure the main sources of heat loss

1.1 Identify losses

Energy loss refers to the loss of energy produced, while heat loss is the loss of heat to a building through its walls and fluid exchanges with the outside world. This study will be based entirely on heat loss, which generally manifests itself in three different ways:

• loss through surface walls ;

• loss through thermal bridges ;

• finally, loss through air renewal and possible leaks.

These losses are all the greater where thermal insulation is poor or non-existent.