The literature review of increasing construction density shows that it can have positive and negative impacts on urban development and a way to urban consolidation. Nevertheless, it may facilitate urban life and enhance quality of life, as two major topics and subjects in the process toward sustainability and sustainable urban development issues. The literature related to the sustainability indicates that, however, there is no consensus on the strengths and weaknesses of both high density and low density, concerning change of quality of life with change of urban density. The extent of comfort or what a habitat is a pleasant place is not measurable with a single quality indicator. There is a range of necessary quality criteria and indicators to be used to measure the extent of comfort and pleasant place. Various qualities include social, such as social safety and crimes, economic, environmental, accessibility and transportation, the rate of visual disturbances, conflicts, cultural & structural issues, such as peers and privacy, comfort climate, etc. All these attributes are not fixed qualities in terms of space and time. Except the indicator of climatic comfort, other qualities are in terms of value fixed approximately a least throughout country. For instance, all people in all cities demand a habitat with a higher rate of social security or desirable access to pedestrian and automobile, providing a better life conditions. However, the climatic indicators are completely related to place and even time. Indicators of climatic and thermal comfort of the vast country of Iran with different climatic regions and variable climatic conditions in different seasons and years, is not fixed definitely. Despite the use of new materials and possibilities of technology which are not economically costly and pollute environment, this variable indicator which is highly dependent on location, is considered to be fixed by urban planners, designers and architects. Direct effect of climatic factors in the formation of habitats, is a known fact. Considering the climatic characteristics and their effects on the formation of habitats raising the qualitative level of comfort and saving energy require controlling the environmental conditions of spaces. This study intends to show that by considering factors of climatic and thermal comfort in determining construction density, which act as effective factors of life, level of comfort for residents promotes considerably. The study use a new residential neighborhood in the city of Rasht, located in the northern region of Iran, namely Golsar Neighborhood. Location analysis was conducted for each factor. Indicators of construction density, floor ratio and the number of story were analyzed. The findings of the study showed the optimum construction density in the study area. Although the humid climate of the city of Rasht justifies low density and expanded city rationally, increasing population and construction densities is unavoidable, mainly because of valuable agricultural land of the region. Increasing construction density and the number of building stories through decreasing building areas provide positive effects on the city development.