Consolidated urban areas usually present a challenge for the sustainable design decisions for the architect. The site, orientation and surrounding built environment compromise both passive and active systems, shortening the possible optimization measures available, leaving the designer with doubts as far as efficiency is concerned.BIM methodologies and visual programming languages have opened up a very wide range of design and analysis tools allowing the architect to make informed decisions based on data extracted from the models. Nonetheless it's optimization is through a slow process of trial and error, creating a significant limitation. This paper discusses the potentialities of the use of evolutionary algorithms to generate optimized solutions for facade solar orientation. A comparison between three different evolutionary algorithms aiming for solar radiation, inside average temperature allows to conclude the best result versus time consumed. Although under similar results the multi-objective EA represents the best compromise between time and final objective on the case study chosen for the paper. The interconnectivity in real time of BIM and algorithmic modeling softwares represents an advantage for time saving sustainable design decisions.

How to analyse the omissions of thermal regulations and evaluate methodologies that provide building execution or thermal certificates that do not correspond to reality and usually incur costs? We can start by analysing different simulation methods and shading calculations that provide solar gains and shadow optimisation. After evaluating how the regulations define the calculation assumptions and how this calculation is performed, the discrepancies (simplifications) that the regulations allow or ignore are presented, and it is exemplified using two case studies. Using the Portuguese regulation as a case study, it leads to incorrect conclusions or assumptions due to unequal access to solar radiation or the shading factor calculation that experiences the omission of angles or time periods. Therefore, the aim is to propose a calculation process (premises) that minimises the discrepancies between simulation (optimisation strategy) and reality (applicability of strategies) for sustainable output.