A green building should be that one designed to reduce the energy consumption.
Nowadays there has been developed an inspection procedure for buildings which allows to survey a property both internally and externally to highlight heat loss and energy wastage. With the help of thermal imaging cameras as in the above photo is possible to highlight the loss of heat from the any green building or not.
Heat energy is transferred from homes by conduction through the walls, floor, roof and windows. It is also transferred from homes by convection. For example, cold air can enter the house through gaps in doors and windows, and convection currents can transfer heat energy in the loft to the roof tiles. Heat energy also leaves the house by radiation through the walls, roof and windows.
There are some simple ways to reduce heat loss, including fitting carpets, curtains and draught excluders. Heat energy loss through windows can be reduced using double glazing with better windows and both passive and active solar. The gap between the two panes of glass is filled with air. Heat energy loss through conduction is reduced, as air is a poor conductor of heat. Heat energy transfer by convection currents is also reduced by making the gap is very narrow.
Heat energy loss through walls can be reduced using cavity wall insulation. This involves blowing insulating material into the gap between the brick and the inside wall, which reduces the heat energy loss by conduction. The material also prevents air circulating inside the cavity, therefore reducing heat energy loss by convection. Heat energy loss through the roof can be reduced by laying loft insulation and this works in a similar way to cavity wall insulation.
It should obviously be a high enough target to eliminate condos and houses that leak like sieves.