The aim of LIGHT is to support the comprehensive, energy-oriented transformation of existing and new urban neighbourhoods while enhancing health and well-being of citizens. As such, LIGHT will explore urban planning strategies centered around integrated solutions designed to enhance both energy performance and human well-being, with a strong emphasis on socio-economic considerations. Our focus includes integrating energy systems with blue-green infrastructure (BGI) to mitigate urban heat island (UHI) effects, optimize daylighting in densified areas, as well as reduce noise and ensure good air quality despite high urban density. By utilizing various tools and techniques, such as participatory scenario modelling and policy development tools, LIGHT thus aims to set a standard for healthy Positive Energy Districts (PEDs) which bring about high quality of life.LIGHT establishes three Urban Living Labs (ULLs) in diverse contexts to test a range of approaches and achieve insights on replicability potential. In Kartuzy, Poland, where there is a critical need for energy-centred regeneration, integrated strategies will focus on energy renovation with particular attention to environmental sustainability and economic feasibility as well as BGI integration. In Lund, Sweden, the focus will be on densification combined with innovative energy generation, entailing carbon-neutral solutions. Within the framework of ULLs, we will also develop an innovative Virtual Urban Living Lab (vULL), involving multi-criteria analyses of various urban densification scenarios, with a particular emphasis on the impacts on health and well-being, especially in relation to noise, air quality, daylight and solar radiation. The vULL will be implemented in a neighbourhood in Innsbruck, Austria, enabling the testing of selected tools and the application of parametric design within these scenarios. All three ULLs will be crucial for testing different scenarios and identifying different feasible energy transition pathways. This approach will support key actors interested in making informed decisions. We will adopt a health and well-being perspective in achieving PEDs, enabling the integration of various objectives related to energy, spatial planning, environmental and social goals, and mobility.These objectives range from reducing energy use and greenhouse gas (GHG) emissions, to improving the quality of life (e.g., access to daylight, air quality, lack of noise, access to green areas, mobility) to enhancing biodiversity and ecosystem services through BGI development. In this approach, health becomes the critical element for integrated planning strategies, serving as a foundation for the strategic transformation framework. In the long run, this contributes to social sustainability while promoting low healthcare costs and high productivity of urban citizens. Through a detailed analysis of synergies, trade-offs, key variables and metrics, we will identify solutions that meet multiple objectives and provide effective strategies for achieving a comprehensive urban energy transition. We will then combine the insights from these tasks to develop a set of online guidelines, digital simulation tools and metrics for PED projects across Europe. By incorporating these insights into our strategic energy-centered urban transformation framework, we will be able to pave the way for replicability of solutions across diverse urban contexts. The information, digital tools, indicators and metrics, processes and insights gained through this project will be disseminated among relevant key players and shared publicly to inspire European communities to embrace the PED transition. The project will also offer an opportunity to refine the PED framework focusing on inclusion, adaptability, and scalability. Overall, the project will demonstrate that European cities can truly lead the way as the LIGHT project will serve as a future model for an effective and inclusive transformation of cities.