Solar shading
Shading is important to reduce excessive solar gain, which can lead to overheating in buildings. It can be applied to both new and existing buildings and development.
Shading devices should be applied to buildings which will have high occupancy, such as offices, schools, hospitals and homes. Design schemes to maximise solar shading during summer months will also need to allow buildings to receive maximum natural light and warmth during the winter in order to reduce the need for additional space heating. Windows facing the sun can be equipped with devices using a louvered design, such as ‘brise soleil’, or aluminium fins to let in light whilst minimising direct sunlight, thus reducing unwanted solar gain, but allow sunlight to enter windows during the winter when the sun is at a lower angle in the sky.
Using brise soleil in an office retrofit
in St Albans to provide shading to
reduce solar gain.
Source: AECOM
Tree canopies can also be used as natural forms of shading. Ideally, deciduous varieties should be used so that the foliage filters out sunlight during summer months when solar gain is unwanted, but allows sunlight through during the winter months when the trees are bare. If trees and green landscaping is to be used in this capacity, it is important to consider which species can be used that are most suited to the climate both now and in the future. Vertical planting on the south façade can filter strong sunlight and provides additional shade. This has the additional benefits of providing evaporative cooling and attenuating water from direct rainfall and surface runoff from the building roof.
Buildings over several storeys could include balconies which would provide shading to the dwelling/floor directly below, as well as outdoor space for the building occupants. This is particularly beneficial in higher-density residential developments where private gardens cannot be provided and space for communal grounds may be limited. Low rise buildings could be designed with an overhang, if balconies are not appropriate. Building overhangs may also offer multiple benefits in terms of protecting façades against extreme weather conditions, such as storms, which may produce heavy precipitation and strong winds.
At the neighbourhood or town/urban extension scale, shading can be provided by using narrow streets or pathways between buildings. This would reduce excessive solar gain but could conflict with ‘right to light’ so careful design consideration is required. It is also important to acknowledge that the layout and
orientation of buildings and streets may channel high winds during storms, causing discomfort or harm to people and property.