Shade

About this pattern

Quality shade is an important civic resource and is critical to human thermal comfort (Bloch, 2019). Shade is often, however, unevenly distributed across the city, with tree canopy roughly proportional to household wealth (Greater Sydney Commission, 2018). Shade structures are needed to provide immediate cool / protection from the sun in environments (such as linkages, nodes or even building interiors), where trees are absent or immature.

While shade needs to be considered as an integral part of the planning phase, it is identified here as a remedial pattern as there are many existing hot environments, particularly away from coastal settlements, where the addition of shade could vastly improve comfort, accessibility and use.

Shade can be fixed or dynamic, natural or artificial, hot or cool, permanent, temporary or worn. There are also many different qualities of shade: type, density, distance from ground and colour matter. Jacobs et al. (2018) at University of Technology Sydney for instance monitored climate adapted bus shelters and found a significant decrease in radiated heat from the ceiling of these structures, largely thanks to the insulated roof panels. Bick (2018), found blue shade sails provided the most effective shade in a study looking at the reduction of light intensity under different coloured shade sails. Shade from sails, however, was not found to be as effective as shade provided by awnings or natural tree canopy.

Trees provide the coolest and most amenable shade, so preserving mature trees wherever possible is a critical first step. Trees provide critical cooling infrastructure in cities and removing them, even if they are replaced, represents a loss potentially of decades of shade, amenity and habitat. In Stuttgart, tree preservation orders protect city trees that have reached a certain circumference from removal.

In areas of urban growth, however, shade needs to be factored back into environments from which trees have already been removed and ‘meanwhile shade’ will be required.

Pattern Conditions

Enablers:

• Strong community support for accessible shade.
• Various cooling and liveability city plans (e.g. Penrith City Council, 2015; Parramatta Ways Walking Strategy, 2017) and academic research (Mellick Lopes et al 2016; Mellick Lopes et al 2019) signal shade as a key consideration to enhance community cooling and urban walkability.
• Increasing urban heat due to climate change and rising incidents of skin cancer in Australia are conditions informing the need for shade. An ameliorating factor might be the increase of non-European migrants whose skin types are more suited to the Australian sun.
  Trees can be slow growing; therefore, other shade measures need to be sought.
• Cancer Council Shade Guidelines and promotion of climate defensive clothing including hats.
• Guide to Conducting a Shade Audit.
• Sun Smart policy has good traction in educational institutions.

Constraints:

• Limitations on planting new trees, shade structures and green façades for climbing vines include: available space in the street scape; the types of soil troughs required for planting; potential conflict with underground or overground utilities, and wheelchair access.
• Different trees provide different quality shade.
• Not all shade is equal – the shade provided by a city building in an otherwise treeless environment, or by other people at a crowded, uncovered bus stop, will not cool! The material covering the ground and surrounds will influence the quality of the shade.
• Some colours are hotter than others. There is a need for community education around the thermal and reflective properties of colour.

Commoning Concerns

Access: depending on where shade is installed it might enhance access for public users, building users, animals seeking refuge from direct sun.

Use: pedestrians, cyclists, building users, park users, animals.

Benefit: all; the lifespans of some materials and finishes might also be improved with the protection of shade.

Care: performed by local government for public spaces; building owner for private spaces; could be a community of commoners for living shade or temporary structures.

Responsibility: all users; community might be tasked with keeping an eye out for problems with shade structures and informing local government or building owners.

Ownership: local government or building owners.

An important commoning concern is the ways in which shade can obscure visibility. For example, a covered park might inhibit the view of the night sky. Temporary shade to shield the sun during the day and open up to the sky at night could be explored.