For improved energy efficiency the building shape will have a high compactness (small form factor) to minimize heat losses/gains through its envelope therefore reducing the heating and cooling demand.

Windows should be oriented south to optimize solar gains in winter period. In some climates the penalization is inferior towards west as a result of high temperatures and a higher probability of clear skies in the afternoon. In northern climates of Europe windows should face within 30° due south for solar gain design.[11] In the central area they may face within 40° and in the southern Europe within 50° due south. Northern windows should be restricted to minimum areas to prevent excessive heat losses. Nevertheless they should allow acceptable levels of daylight for visual performance and minimize energy consumption for lighting. All strategies adopted should take into consideration the local climatic conditions as well as the site layout.

3.2 Shading

Building shading may be a result of the building itself, external obstructions and shading devices. Appropriate solar control should be planned to avoid overheating of the adjacent spaces during the hot period. Overhangs are good systems to obtain a good solar control in south oriented surfaces. Because the solar altitude is lower on east and west orientations solar control is more complicated. Vertical fins and movable devices apply. Whenever possible, exterior shading devices should be used to prevent heat gains entering the space.