Urban environments are getting warmer and warmer because of climate change so there is a need for interventions that can help with cooling. These interventions should also provide co-benefits. A lot of microclimate studies only focus on a few fixed points, or street-wide averages
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Urban environments are getting warmer and warmer because of climate change so there is a need for interventions that can help with cooling. These interventions should also provide co-benefits. A lot of microclimate studies only focus on a few fixed points, or street-wide averages and rarely look at conditions adjacent to an intervention or along a route regarding thermal comfort. Co-benefits such as added bioretention surface area and CO₂ uptake are almost never looked at alongside thermal comfort. To tackle those gaps three nature-based solutions (NBS) scenarios are tested in a thermally uncomfortable street in Amsterdam on the hottest day ever recorded in the city (25 July, 2019), these NBS scenarios are: green façades, bioswales and vegetated pergola. The ENVI-met model had input data of a local weather station and was validated against observations of the Schiphol weather station. So it is used to look at the whole-street conditions and 2 meter wide buffer zones for each NBS intervention at 18:00 and 23:00. A walk-based Physiological Equivalent Temperature (PET) tool of ENVI-met showed proper pedestrian exposure during a route. The Timorpleinbuurt-Zuid neighborhood was selected as a study-case because it is a neighborhood with a lot of high heat exposure and it has a low amount of public green space, so a high impervious cover, but also has urgent rainwater risk, and a high social vulnerability to heat, and it provides local weather data for validation. The results depend on both NBS type and analysis scale (bufferzone or whole street). The pergola has the strongest relief at 18:00, largely seen within its buffer zones where shade covers the sidewalk. Green façades cool more consistently at the street scale and are also staying effective into the evening, while also improving comfort in the bufferzones. The bioswales provide a low amount of thermal comfort at both scales but it has the highest amount of added bioretention surface area and the highest reduction in CO₂ levels. So there are trade-offs so a mixed strategy is recommended. This would be having pergolas on the sun exposed walking routes, green façades to block incoming sunlight on building facades to help with whole street-scale and thermal comfort at 18:00 and 23:00, and bioswales to increase the bioretention surface area and air-quality goals. The bufferzone and walk-based PET are a good way to evaluate the single NBS interventions where people actually move.