*Review* **Basic Principles, Most Common Computational Tools, and Capabilities for Building Energy and Urban Microclimate Simulations**

**George M. Stavrakakis 1,2,\*, Dimitris Al. Katsaprakakis <sup>1</sup> and Markos Damasiotis <sup>3</sup>**


**Abstract:** This paper presents basic principles of built-environment physics' modelling, and it reviews common computational tools and capabilities in a scope of practical design approaches for retrofitting purposes. Well-established simulation models and methods, with applications found mainly in the international scientific literature, are described by means of strengths and weaknesses as regards related tools' availability, easiness to use, and reliability towards the determination of the optimal blends of retrofit measures for building energy upgrading and Urban Heat Island (UHI) mitigation. The various characteristics of computational approaches are listed and collated by means of comparison among the principal modelling methods as well as among the respective computational tools that may be used for simulation and decision-making purposes. Insights of coupling between building energy and urban microclimate models are also presented. The main goal was to provide a comprehensive overview of available simulation methods that can be used at the early design stages for planning retrofitting strategies and guiding engineers and technical professionals through the simulation tools' options oriented to the considered case study.

**Keywords:** building energy performance; urban heat island; building physics; simulation tools
