The present work addresses the contribution of local urban design towards the development of a comfortable microclimate at street level for pedestrians. The current environmental agenda for urban design points towards compact urban form and walkable polycentric city structures. In designing connected street patterns as social places that enhance permeability, a certain degree of complexity seems to be deemed necessary to avoid the monotony of a rigid grid and thus, provide environmental diversity and freedom of choice. The two latter concepts have been found to affect crucially the thermal sensation and microclimatic preconceptions of pedestrians and consequently their use of public space.Walking in the city and having the possibility to do so comfortably and safely in terms of environmental conditions seems to form an informal measure of space quality with environmental benefits, as well as socio-economic correlations. Central point of this research is the pedestrian network of streets and squares and their urban morphology (fine urban grain). Recent studies in urban design emphasise the importance of environmentally friendly (‘sunlit, wind- and pollution-free’) spaces and successful places with vitality. Metropolitan city centres provide an example of a palimpsest of urban patterns and historical urban layers that present adaptive opportunities to continuous use and vitality. In view of the current debate on sustainability and compact urban form, the research addresses the quality of pedestrian street movement in relation to the awareness of available choices through environmental diversity. The latter is defined as the spatial and temporal variation in the environmental conditions of the different urban spaces that form the pedestrian network (including, along with the linear street element, different spatial configurations that form widenings and small squares along main routes). In that context, emphasis is given on the microclimatic variations between different ‘thermal urban rooms’ and their influence on the outdoor environment and users’ comfort.Addressing pedestrian movement through a methodology of sequential analysis, along with the assessment of variations in the thermal sensation of users through ‘microclimatic walks’, could lead to a greater understanding of use patterns, pedestrian experience and behaviour. The degree of diversity that results from different urban geometries along street networks (more realistic forms in dense historic cores) is coupled with the relevant occupancy and frequentation patterns by people on a daily basis and also between seasonal variations. The expected outcome will provide an insight in the link between microclimatic conditions and pedestrian experience of dense street networks. One of the main research aims is to develop an architectural language that integrates information of pedestrian thermal comfort in the design process.