• Energy Research

As urban heatwaves become more severe, frequent and longer, cities seek adaptive building cooling measures. Although passive building design, energy-efficient materials and technologies and mechanical means are proven cooling methods, the potential of nature-based solutions (particularly trees as shading elements) has been understudied despite its significant opportunity. Using a new framework to explore this at the neighbourhood level, three future (2050) potential tree planting strategies are modelled for increasing tree volume and canopy cover and their impacts assessed for summer building-level solar radiation absorption (SRA) and building cooling energy demand (BCED) for a densifying neighbourhood in Vancouver, Canada. The boldest tree planting strategy, with 287% more trees than baseline and 16% canopy cover, reduced neighbourhood-scale total SRA (22%) and BCED (48%) over a no-trees scenario. BCED reductions of up to 64% for retrofitted/redeveloped buildings and 53–79% for low/medium-height buildings (mostly single-family residential) were associated with targeted south-side tree planting. Taller/larger buildings (predominantly mixed use) and buildings along north–south-oriented streets (mainly commercial and mixed use) encountered more tree shading challenges and would require more site-specific interventions. The methodology presented provides a framework to assess current and potential future shading and cooling energy benefits through various tree planting strategies. Practice relevance This research illustrates the tree shading and cooling potential to improve indoor liveability, reduce energy demand and reduce vulnerabilities amidst mounting extreme heat risks. This novel framework and method can be used by planners and urban designers to understand the potential cooling reduction and to develop tree planting and management strategies for effective shading and indoor cooling at the neighbourhood scale. Based on a case study neighbourhood in Vancouver for 2050 climate scenarios, this research shows increased tree volume and canopy cover can significantly reduce building SRA and BCED during the summer. The level of tree shading impact on buildings’ SRA and BCED was associated with the intensity and location of tree planting, but also the relative amount of lower height (and smaller) buildings. The boldest tree planting strategy yielded a 48% reduction in energy demand for cooling.

As urban heatwaves become more severe, frequent and longer, cities seek adaptive building cooling measures. Although passive building design, energy-efficient materials and technologies and mechanical means are proven cooling methods, the potential of nature-based solutions (particularly trees as shading elements) has been understudied despite its significant opportunity. Using a new framework to explore this at the neighbourhood level, three future (2050) potential tree planting strategies are modelled for increasing tree volume and canopy cover and their impacts assessed for summer building-level solar radiation absorption (SRA) and building cooling energy demand (BCED) for a densifying neighbourhood in Vancouver, Canada. The boldest tree planting strategy, with 287% more trees than baseline and 16% canopy cover, reduced neighbourhood-scale total SRA (22%) and BCED (48%) over a no-trees scenario. BCED reductions of up to 64% for retrofitted/redeveloped buildings and 53–79% for low/medium-height buildings (mostly single-family residential) were associated with targeted south-side tree planting. Taller/larger buildings (predominantly mixed use) and buildings along north–south-oriented streets (mainly commercial and mixed use) encountered more tree shading challenges and would require more site-specific interventions. The methodology presented provides a framework to assess current and potential future shading and cooling energy benefits through various tree planting strategies. Practice relevance This research illustrates the tree shading and cooling potential to improve indoor liveability, reduce energy demand and reduce vulnerabilities amidst mounting extreme heat risks. This novel framework and method can be used by planners and urban designers to understand the potential cooling reduction and to develop tree planting and management strategies for effective shading and indoor cooling at the neighbourhood scale. Based on a case study neighbourhood in Vancouver for 2050 climate scenarios, this research shows increased tree volume and canopy cover can significantly reduce building SRA and BCED during the summer. The level of tree shading impact on buildings’ SRA and BCED was associated with the intensity and location of tree planting, but also the relative amount of lower height (and smaller) buildings. The boldest tree planting strategy yielded a 48% reduction in energy demand for cooling.

Municipalities face the direct impact of climate change events, but many are challenged to assess the potential outcomes of future climate action policies. It is essential for local municipalities to be able to evaluate cross-sector and cross-scale policy interventions, but many lack the expertise and resources for wholistic forecasting. This paper used a hybrid inter-scalar and interdisciplinary modeling approach to evaluate, compare, visualize, and reveal the performance of climate actions at building and neighbourhood scales of future ‘what-if’ scenarios for three neighbourhood urban form types (dispersed, corridor, nodal) in three cities in British Columbia, Canada (Vancouver, Victoria, Prince George). Results found that increases in population density combined with strict building standards and retrofitting older buildings decreased per person emissions per year by up to 84% by 2050. Within the neighbourhood-scale areas, building form and location had less impact. Population density and frequency of transit service were most important for mobility mode shifts. Concentrating density at transit nodes or along commercial corridors improved the percentages of residents within a five-minute walk of those services, but proximity to greenspaces showed mixed results. 'Policy relevance' Municipal climate action policies cross sectors and scales. This analysis of future urban form and energy scenarios at neighbourhood scales reveals livability and greenhouse gas (GHG) outcomes. It provides evidence that compact neighbourhood form coupled with stringent building codes reduces GHG emissions. (1) Concentrating density at transit nodes or along commercial corridors improved the percentages of residents within a five-minute walk of those services, but proximity to greenspaces showed mixed results. (2) Within neighbourhood-scale areas urban form (building form and location) had less influence on shifting mobility modes than did overall population density and transit frequency. (3) British Columbia’s net-zero-ready building code, a performance-based code, resulted in notable energy-use reductions and related emissions reductions associated with the new building stock. (4) Retrofitting the existing building stock resulted in notable emissions reductions in the three neighbourhoods; however, for cities with growing high land value, the potential for sale and redevelopment is a disincentive to retrofitting.

Municipalities face the direct impact of climate change events, but many are challenged to assess the potential outcomes of future climate action policies. It is essential for local municipalities to be able to evaluate cross-sector and cross-scale policy interventions, but many lack the expertise and resources for wholistic forecasting. This paper used a hybrid inter-scalar and interdisciplinary modeling approach to evaluate, compare, visualize, and reveal the performance of climate actions at building and neighbourhood scales of future ‘what-if’ scenarios for three neighbourhood urban form types (dispersed, corridor, nodal) in three cities in British Columbia, Canada (Vancouver, Victoria, Prince George). Results found that increases in population density combined with strict building standards and retrofitting older buildings decreased per person emissions per year by up to 84% by 2050. Within the neighbourhood-scale areas, building form and location had less impact. Population density and frequency of transit service were most important for mobility mode shifts. Concentrating density at transit nodes or along commercial corridors improved the percentages of residents within a five-minute walk of those services, but proximity to greenspaces showed mixed results. 'Policy relevance' Municipal climate action policies cross sectors and scales. This analysis of future urban form and energy scenarios at neighbourhood scales reveals livability and greenhouse gas (GHG) outcomes. It provides evidence that compact neighbourhood form coupled with stringent building codes reduces GHG emissions. (1) Concentrating density at transit nodes or along commercial corridors improved the percentages of residents within a five-minute walk of those services, but proximity to greenspaces showed mixed results. (2) Within neighbourhood-scale areas urban form (building form and location) had less influence on shifting mobility modes than did overall population density and transit frequency. (3) British Columbia’s net-zero-ready building code, a performance-based code, resulted in notable energy-use reductions and related emissions reductions associated with the new building stock. (4) Retrofitting the existing building stock resulted in notable emissions reductions in the three neighbourhoods; however, for cities with growing high land value, the potential for sale and redevelopment is a disincentive to retrofitting.

As efforts to address climate change shift to action at local scales, municipalities are called upon to develop locally specific action plans. Many municipalities lack the resources to develop energy and emissions-reducing policy interventions appropriate to their characteristics. This research synthesises urban form, scenario analysis and energy simulation into a cohesive workflow for evaluating energy and emissions policy interventions across a range of urban forms. A geospatial and census analysis of six cities across British Columbia, Canada, led to the development of seven urban neighborhood patterns. These represent neighborhood forms and densities found in cities of various sizes, densities, forms and climates. To test the approach of an urban built environment model (UBEM), retrofit and infill redevelopment ‘what-if’ scenarios were applied iteratively to two sample patterns comparing the relative efficacy of building technology-improvement policies versus land-use intensification policies. The future ‘what-if’ policy scenarios were spatially tested and validated using relevant policy. The simplified UBEM methods applied to typical patterns and development demonstrates a step towards an accessible and flexible modeling approach. Small and medium-sized municipalities can use this approach to assess and compare potential energy and emissions policy options and outcomes at building and neighborhood scales. 'Practice relevance' A new, simple method has been created for municipalities to understand multiple ‘what-if’ scenarios for reducing energy demand and emissions from buildings. This is based on profiles from census data, geospatial analysis and energy data that characterise urban neighborhood patterns. The approach integrates building-scale and neighborhood-scale energy and greenhouse gas simulations. It can simulate a variety of policy scenarios and strategy interventions in order to show the interactions between and among urban form and retrofit options. This enables planners and decision-makers to compare the relative magnitudes of different interventions at the neighborhood or city level for energy and emissions performance. The model was developed for use by a variety of communities in British Columbia, Canada. There is potential for adapting this method for use in other locations.

As efforts to address climate change shift to action at local scales, municipalities are called upon to develop locally specific action plans. Many municipalities lack the resources to develop energy and emissions-reducing policy interventions appropriate to their characteristics. This research synthesises urban form, scenario analysis and energy simulation into a cohesive workflow for evaluating energy and emissions policy interventions across a range of urban forms. A geospatial and census analysis of six cities across British Columbia, Canada, led to the development of seven urban neighborhood patterns. These represent neighborhood forms and densities found in cities of various sizes, densities, forms and climates. To test the approach of an urban built environment model (UBEM), retrofit and infill redevelopment ‘what-if’ scenarios were applied iteratively to two sample patterns comparing the relative efficacy of building technology-improvement policies versus land-use intensification policies. The future ‘what-if’ policy scenarios were spatially tested and validated using relevant policy. The simplified UBEM methods applied to typical patterns and development demonstrates a step towards an accessible and flexible modeling approach. Small and medium-sized municipalities can use this approach to assess and compare potential energy and emissions policy options and outcomes at building and neighborhood scales. 'Practice relevance' A new, simple method has been created for municipalities to understand multiple ‘what-if’ scenarios for reducing energy demand and emissions from buildings. This is based on profiles from census data, geospatial analysis and energy data that characterise urban neighborhood patterns. The approach integrates building-scale and neighborhood-scale energy and greenhouse gas simulations. It can simulate a variety of policy scenarios and strategy interventions in order to show the interactions between and among urban form and retrofit options. This enables planners and decision-makers to compare the relative magnitudes of different interventions at the neighborhood or city level for energy and emissions performance. The model was developed for use by a variety of communities in British Columbia, Canada. There is potential for adapting this method for use in other locations.