3.4. Building layout

Therefore, the buildings form and the layout of the urban matrix can influence sustainability of the urban block and cities. Such impact on an example of buildings in Mediterranean climate is shown in Figure below.

Figure 3.28Heating and cooling demand relative to the form of the buildings and urban block[48]

The building form influences the quality of the daylight and use of artificial lighting in the interior. An elongated building can have as much as a 15-25% reduction in energy use over a compact building of the same size, due to its greater ability to use daylight. The following guidelines for buildings forms in relation to daylight can be met:

 Narrow buildings use less energy in total as they can be more effectively day lit, leading to a reduction in electrical load, which outweighs any slight increase in fabric losses due to a large façade area.  Courtyard buildings do not perform as well as shallow buildings since they have less daylight and natural ventilation.  Atrium buildings perform in a similar way as courtyard buildings, although the ventilation is better than in courtyards (due to stack effects). There may be a need to include mechanical ventilation in the upper floors due to the low stack pressures at higher levels.

Independent of the building concept, an optimum arrangement of the layout can result in 10 to 20 % energy savings.

The orientation of buildings with same shape but differently arranged living areas and glass surfaces will require different orientations to take the best advantage of the solar insolation. There are many recommendations for room orientation. Recommendations for residential buildings above 35° latitude are given in Table 3.2. The position of the spaces in residential building is proposed according to their optimal orientation[45]. For determining the orientation the occupancy hours of the spaces should be considered. Also, another factor of the orientation is the germicidal sanitization effect ofthe solar radiation.