The purpose of this research is to investigate the thermal impact of urban green systems (UGS) (trees and living facades) and high albedo pavements on reducing the urban heat island (UHI) effect in London at the pedestrian street level. The research assesses the impact of UGS by suggesting practicable urban greenery-covering densities (25% and 50%) and using high albedo pavement in current and future climatic scenarios (2050 and 2080). This approach is intended to encourage pedestrians to walk longer distances for longer durations during the warmer months, following the Transport for London’s (TfL) 2017 Healthy Streets initiative. The research seeks to measure the advantages and assess the possible impact on the comfort and activities within urban streets. The study adopts a quantitative research design using ENVI-met modelling and questionnaires. Simulation results, the subject of this paper, confirmed that, across three climatic scenarios, the optimal UGS for thermal comfort is 50% trees followed by 25% trees, dependent on street orientation and solar access. Living facades (LF) with 25% and 50% covering had no discernible effect on the comfort of pedestrians, whereas high albedo pavement increases heat stress.

With growing concerns over energy and heat-related mortality/morbidity rates, enhancing building performances is key to improving the health and well-being of building occupants while reducing CO₂ emissions, in line with the UK Government’s Net-Zero targets. This study investigates the impacts of different retrofitting scenarios on overheating risk and energy performance in social housing for current and future climate conditions. Dynamic thermal simulations were carried out using Design Summer Year (DSY) weather files in DesignBuilder software for selected case study buildings. Winter performance was analysed using the Predicted Mean Vote (PMV) index, while summer results were assessed according to the Chartered Institution of Building Services Engineers Technical Memorandum 59 (CIBSE TM59) guidelines. The findings revealed that bedrooms, especially those facing south, were at high risk of overheating. Factors such as building construction, the number of exposed surfaces, and window area influenced the risks. External wall insulation outperformed internal wall insulation in improving summer comfort. In the winter, Passivhaus standards with natural ventilation ensured thermal comfort across all zones, with a 41–53% reduction in heating energy consumption under current weather conditions. The risk of overheating and associated health issues significantly increased for the future weather scenarios. Further investigation into ventilation strategies, occupant behaviour, and passive design is required to mitigate overheating risks while reducing energy consumption in buildings.