The United Nations have identified climate change as the greatest threat to human life. As current research shows, urban areas are more vulnerable to climate change than rural areas. Numerous people are affected by climate change in their daily life, health and well-being. The need to react is undisputed and has led to numerous guidelines and directives for urban climate adaptation. Plants are commonly mentioned and recommended as one key to urban climate adaptation. Due to shading of open space and building surfaces, as well as evapotranspiration, plants reduce the energy load on the urban fabric and increase thermal comfort and climate resilience amongst many other ecosystem services. Plants, therefore, are described as green infrastructure (GI), because of the beneficial effects they provide. Extensive green roofs are often discussed regarding their impact on thermal comfort for pedestrians and physical properties of buildings. By means of Stadslab2050 project Elief Playhouse in Antwerp, Belgium, a single-story building in the courtyard of a perimeter block, the effects of different extensive green roof designs (A and B) on the microclimate, human comfort at ground and roof level, as well as building physics are analyzed and compared to the actual roofing (bitumen membrane) as the Status Quo variant. For the analyses and evaluation of the different designs the innovative Green Performance Assessment System (GREENPASS^®) method has been chosen. The planning tool combines spatial and volumetric analyses with complex 3D microclimate simulations to calculate key performance indicators such as thermal comfort score, thermal storage score, thermal load score, run-off and carbon sequestration. Complementary maps and graphs are compiled. Overall, the chosen method allows to understand, compare and optimize project designs and performance. The results for the Elief Playhouse show that the implementation of green roofs serves a slight contribution to the urban energy balance but a huge impact on the building and humans. Variant B with entire greening performs better in all considered indicators, than the less greened design Variant A and the actual Status Quo. Variant B will probably bring a greater cost/benefit than Variant A and is thus recommended.

Adapting spatial development to the challenges of climate change is a major task facing cities. In particular, urban heat islands caused by increasing average temperatures and urban growth are a challenge for cities. The use of climate simulations to assess current and future urban heat stress is a helpful approach for supporting this transition. In particular, green and blue infrastructure helps to reduce the urban heat island effect. These cooling effects can be analysed using simulations. However, a central challenge is that urban adaptation to heat needs to be implemented consistently at different planning levels. A second major challenge in adaption is identifying the amount of urban green infrastructure required in order to achieve a specific cooling benefit and establishing this by means of planning instruments. This article presents two case studies in the city of Vienna to demonstrate how climate simulation tools can be used across different planning levels if they are standardized. When combined with a green and open space factor as a steering instrument, the necessary amount of greening for subsequent planning processes can be secured. The result is a multi-scale toolset consisting of three climate simulation models and a green and open space factor, coordinated, and standardised for use at different levels of planning.

The implementation of nature-based solutions (NBS) in urban regeneration aims to improve citizens’ health and well-being. Therefore, tools need to be applied to identify the most suitable and efficient location and type of NBS. Within the CLEVER-cities H2020 project, the Greenpass method has been chosen to evaluate different design solutions regarding thermal comfort and physiological equivalent temperature (PET), energy, water and air fluxes. The Greenpass system comprises of standardized tools, reports and a unique set of Key Performance Score (KPS) and Key Performance Indicators (KPI). This paper deals with the impact assessment of NBS by the use of the innovative Greenpass system for the CLEVER-cities project ‘Fischbeker Höfe’ in Hamburg, Germany to ensure human health and well-being improvements for the citizens. To that end and considering the climate change context, thermal comfort is a KPI with high relevance in terms of the NBS co-benefits. Based on the PET within a project area Greenpass calculates the Thermal Comfort Score (TCS). The share of the different PET classes within the project area is multiplied with a weighting factor and summarized to the TCS. The results of the climate resilience analysis of the urban development area ‘Fischbeker Höfe’ in Hamburg are presented and discussed in comparison to a conventional architecture that disregards NBS, showing improvement with regards to four out of five KPS. Based on the evaluation results, advice is given to the co-creative design team on how to further improve the design towards climate resilience. The Greenpass system has proven to be a powerful and tailored tool to support climate resilient urban design and architecture. It provides a standardized and comprehensible but still scientific basis for decisions in a highly efficient and understandable way.

Urban growth and climate change are 2 of the main challenges worldwide [20]. Cities are growing rapidly while average temperatures are rising, and extreme weather conditions, as heavy rain events, are becoming more frequently. Soon 4 out of 5 EU citizens are living in cities [6]. The results are increasing costs for health expenses and infrastructure damages. Urban planning processes have to consider future climate conditions and the impact on people, buildings and the urban environment. Until today there was no simple solution to measure and calculate the climate impacts of urban developments. GREENPASS® is a technological breakthrough, the world’s first software-based technology for climate-resilient and resource-efficient urban development. After 9 years of scientific research and development the technology can easily be used by urban planners as architects and be integrated into existing urban planning workflows and processes. With GREENPASS® the impact of buildings, materials and plants on urban climate become measurable and comparable in a standardized way – powered by ENVI-met®. It supports optimization of investments towards effects of Green Infrastructure (trees, green roofs and walls, …) such as cooling, thermal comfort, water retention and carbon sequestration. GREENPASS® allows to identify the optimal solution for any urban development. Supported projects receive finally a GREENPASS® certificate on their overall performance. The technology has already been applied successfully for more than 25 projects within Austria and Europe [3] and will be explained more in detail using the case study of ‘FLAIR in the City’ - the world’s first GREENPASS® Gold-certified residential building, located in Vienna/Austria.