Controlling the temperature difference and air movement between inner and outer surfaces of walls, floors and ceilings is the best opportunity for reducing heat conduction. Sunlight will be increasingly reflected by the glass as the sunlight departs from the perpendicular. The role of landscape vegetation in conserving energy varies with the different microclimates across North Carolina. In the cooler, northwest areas of North Carolina, where enormous amounts of energy are consumed in winter heating, control of air infiltration is paramount. Hotter southeastern areas place more emphasis on use of shade to control heat conduction and reduce the need for summer air-conditioning.
Trees can reduce summer temperatures significantly.
Shading the roof of a house from the afternoon sun by large trees can reduce temperatures inside the home by as much as 8 to 10 degrees F. Deciduous trees provide summer shade, then drop their leaves in the fall. This allows the warmth of the sun to filter through their bare branches in winter and helps warm the home. If a home can be situated to take advantage of shade from existing trees on southeast and west exposures, energy expended to cool the house can be reduced. If there are no existing trees, the owner can select and place trees that ultimately will provide shade. The temptation is to plant the fastest growing species available.