The study presented in this paper is part of a PhD research titled 'Comfortable and Healthy Urban Environments'. This PhD research aims at gaining insight into the relationship between building densities, building patterns, building types on the one hand and the main aspects of the physical urban climate on the other hand: penetration of daylight, solar irradiation of façades and outdoor spaces, wind, air temperature, air quality and (traffic) noise. The research focuses on the first stages of urban design since the decisions regarding urban geometry in those early stages are of great influence on the urban climate in the final design. The urban tissue is therefore reduced to its basic geometries. In this way the conditions for the outdoor climate as well as the base conditions for the indoor climate (at the position of the façade) can be studied. This paper reports on studies into daylight and wind comfort aspects. The research shows that building densities have quite an influence on daylight access and the wind climate within the street. Within a fixed density the choice of building type also has a significant influence.