Smart Surfaces
A group of technologies and design strategies that mitigate the effects of dark and impervious surfaces and climate change in urban environments—especially extreme heat, stormwater flooding, and poor air quality. Smart Surfaces include green infrastructure (trees, rain gardens, urban meadows, green roofs), reflective (cool) roofs and pavements, porous and permeable pavements, solar PV, and combinations of these surfaces.
Cool Roof
Also called “reflective roofs,” these are roof coverings engineered to reflect more sunlight than dark-colored roofs. Dark-colored roofs absorb the vast majority of solar energy that falls on them, radiating that energy as heat into the building and the surrounding air – in contrast, cool roofs reflect sunlight back into space, reducing heat gain and lowering the cooling burden of the spaces they cover.
Green Roof
Roof coverings consisting of living vegetation that absorb rainwater and provide passive cooling for buildings while mitigating urban heat island through the process of evapotranspiration. Green roofs help reduce stormwater runoff, increase building energy efficiency, improve air quality, provide habitat, and create attractive communal space on occupied roofs.
Solar Photovoltaic Roof
A solar roof is any roof covering that includes electricity-generating solar photovoltaic (solar PV) panels. Solar roofs can help reduce a building’s energy costs and carbon footprint, and help shade green roofs from excess direct sunlight (reducing watering needs).
Combination Roof
As used throughout this tracker, combination roof refers to any roof covering consisting of a combination of reflective, vegetated, or solar components. Note: combining Solar PV with Green and Cool Roofs increases the energy output of the solar panels (because of cooler roof surface temperatures).
Reflective Pavement
Pavements that are engineered to reflect a greater proportion of incident sunlight, reducing thermal energy stored in the pavement, reducing ambient temperatures above the pavement and city-wide, and extending the lifespan of the underlying pavement material.
Porous/Permeable Pavement
Smart pervious pavement technologies include permeable articulating concrete blocks, permeable interlocking concrete pavers, porous concrete, and porous grid pavers with turf or gravel. In addition to reducing flood risk and water pollution, porous pavements can lower temperatures through evaporative cooling and increased reflectivity versus conventional dark asphalt pavement.
Tree Canopy
Tree canopy provides a host of benefits in an urban environment. Counteracting the vast expanses of dark-colored pavement that dominate cities, urban tree canopy provides shade, cooler air via evapotranspiration, improved air and water quality, carbon sequestration, reduced stormwater runoff, biophilic human health benefits, and critical habitat for birds, insects, and small mammals.
Low-, Zero-, and Negative-Carbon Concrete
Concrete mixes that directly sequester carbon dioxide from the atmosphere and/or that include lower embodied carbon mixtures than traditional concrete mix.
Green Stormwater Infrastructure
Green stormwater infrastructure refers to a broad range of nature-based infrastructure designed to collect and filter stormwater runoff, including rain gardens, bioswales, green roofs, filter strips, and more. In addition to collecting and filtering stormwater runoff, these features reduce urban air and surface temperatures, promote biodiversity and add aesthetic value.
Solar PV Canopies
Solar PV converts sunlight into electricity and in canopy form can provide shade for buildings, sidewalks, and other public areas. Solar surfaces can help cities reduce their reliance on fossil fuels, increase grid reliability, and cut greenhouse gas emissions while reducing air pollution and energy costs.
Shade Structures
Structures designed explicitly to provide shade in public spaces, such as parks, bus stops, and along sidewalks.
Parkland
Vegetated areas set aside to be kept relatively (or completely) free of built structures and impervious surfaces.
Habitat Spaces
Areas of a city set aside to be maintained in a way designed explicitly to protect and enhance biodiversity.
Urban Meadows
Planted areas of native grasses and herbaceous flowering plants that can take the spot of vacant lots and turfgrass lawns in urban areas. Urban meadows reduce urban heat island effects, support biodiversity, help mitigate flooding by managing stormwater better than turfgrass lawns, and reduce the maintenance costs associated with mowing and watering.
Wetlands
Wetlands are areas where water is at or near the surface of the soil for significant portions of the year. As an alternative to impervious areas in a city, wetland surfaces support biodiversity and can mitigate the effects of excess rainfall.
