The number of people living in cities in Slovenia is increasing. There fore, the city spreads, urban space is created mostly by different buildings with minimum of open space, usually designed for parking spaces. But despite the fact, that urban structure is spreading, and there should be more of public open spaces, or green open spaces, those are in many cases reached by developers as well. Despite global worming, higher temperatures in city centres and what appears to be what citizens want, the urban open spaces are not big enough, and are usually not designed with key elements, to improve quality of lifestyle in the urban space such as trees, water or natural elements. Therefore at all levels of urban planning it is necessary to strive for larger amount of space that could be designed as public open space or green space to improve quality of life in the city.