Final answer:
True, in construction best practices dictate leaving a clearance between the bottom of the exterior wall covering and the roof surface, which allows for proper drainage and accommodates building movement, while contributing to energy efficiency by minimizing thermal bridges.
Step-by-step explanation:
In construction, the intersection where the roof meets the exterior wall is critical to the overall health of the building. It is considered best building practice to leave some clearance between the bottom of the exterior wall covering and the roof surface.
This clearance allows for proper drainage, prevents water infiltration, and accommodates thermal and moisture-related movement between the building elements. It helps in maintaining the energy efficiency of a building by minimizing thermal bridges, where significant heat transfer can occur.
More specifically, in Passive House construction, careful attention is paid to the details of thermal bridging to maintain a high standard of energy efficiency.
Ensuring proper clearances and the use of high-performance building materials contributes to achieving the desirable thermal coefficients of 0.15 W/°C per square meter for the external-interfacing surface and 0.8 W/°C per square meter of overall external surface area, which are vital stats for Passive Houses.
To maintain the building's energy efficiency, only half-thickness of exterior walls is typically considered to be at the interior temperature, acknowledging that the temperature gradates from the heated interior towards the cooler outside.