Regulated energy loads of buildings are typically explored at the scale of individual buildings, often in isolated (and idealized) circumstances. By comparison, little research currently exists on the performance of building groups that accounts for the interactions between buildings. Consequently, the energy efficiency (or penalty) of different urban configurations (such as a city street) is overlooked. The present paper examines the energy demand of a city street in London, UK, which is comprised of typical office buildings with internal energy gains associated with daytime occupancy. Simulations are performed for office buildings placed in urban canyons that are defined by the ratio of building height (H) to street width (W). The results show the annual energy demand is dominated by the cooling load, which can be significantly reduced through street design that provides shading by increasing H/W. However, the ‘best’ street design for modern office buildings may be incompatible with that for residences or, for that matter, outdoor climates.

High temperatures and heatwaves are becoming more frequent, but heat vulnerability is rarely considered within local authority city design and statutory land-use planning processes. Here, we describe an approach to assess heat vulnerability in Birmingham, the second largest city in the UK. The approach uses open access data and GIS techniques that are available for built environment practitioners. Heat vulnerability is assessed by combining four datasets: surface temperatures, Local Climate Zones, green space, and Indices of Multiple Deprivation. The assessment shows that central and eastern areas of Birmingham that have the most compact urban form, least green space, and highest levels of deprivation are most vulnerable to heat. We evaluated the approach against previous climate research, examined the approach and datasets at the local scale, and described how heat vulnerability can be (and is being) incorporated into decision making. This project combines three key innovations: (1) the decision-centric process that focuses the method on the decision that needs to be made, minimizing inertia related to scientific or modeling uncertainty and reducing resource-intensity; (2) the co-creation process with Birmingham City Council, who have statutory powers for planning within the city, thereby ensuring that heat vulnerability is embedded within decisions on the suitability, design, and location of sites for future development; and (3) the open access and technically appropriate methodology which can be applied to any urban area in the UK, using the open access datasets described here, or globally, using locally applicable data sources.

The existing methods of selecting design summer year weather data rely on the outdoor dry bulb temperature without considering solar radiation and wind which can impact on indoor thermal conditions. This research sets out to examine the existing outdoor warmth ranking metrics and proposes a new warmth ranking metric (solar air temperature), which takes into account not only dry bulb temperature but also solar and wind conditions. Parametric study was carried out using five typical UK dwelling models, by varying parameters associated with building design and operation, a large model population were generated to statistically determine how well the outdoor warmth ranking metrics correlate the predicted indoor warmth. The outdoor warmth ranking was made for the 20 years source weather data (1976–1995) in London and both CIBSE single temperature criterion and BS EN 15251 adaptive criteria were used to judge overheating in buildings. It is found that the predicted indoor warmth are mostly arbitrary in nature and none of the existing and newly proposed outdoor warmth ranking metrics can strictly correlate. The research also discovers the significant differences between the predicted overheating occurrence and severity in the warmth ranking of weather years. Practical application: The parametric methods described in the paper will facilitate academics and industry researchers to assess design summer year weather generated by various methods. The research also provides guidance on assessing both overheating occurrence and severity in buildings to assist decision making.