The planned re-use of the Berlin Tegel Airport has been analysed with respect to its impacts on urban climate by using the flow model ENVI-met. Investigations focus on micro scale effects within the center of this 4.95 square kilometers wide area. The micro climate impact of new buildings according to the city development project „The Urban Tech Republic“ is determined. After giving a comprehensive overview on urban climate adaptation measures different simulations concerning mentioned adaptation strategies are presented. Further evaluation relates mainly to the human heat stress. This is estimated and classified with the help of the „Physiological Equivalent Temperature“ (PET). The results of the micro scale investigation indicate a reduced heat stress in fact of the airport re-use mainly caused by the shading across the new buildings. In spite of the massive reduc-tion related to the initial situation, heat stress is still within the highest category „very strong heat load“. Adaptation scenarios regarding the increase of soil albedo and insulation of buil-ding walls may fail by inducing an increased heat load. Other scenarios show only a circum-stantial effect due to several reasons. Parks have the most intense impact on reducing heat stress between buildings. Two additional scenarios consisting of combinations of different adaptation measures do not create an added value in general. In the given add-on city development advices which are also applicable to the coming re-use of the Berlin Tegel Airport green spaces are an important item.