Since the 1990s, Vienna’s existing building stock has been under Financial incentives are offered to encourage citizens to take continuous refurbishment programs, delivering an important action. To ensure that housing costs stay affordable, and to reduction in energy consumption and carbon footprints. Subsidies fight against energy poverty, Vienna City Council strongly from the City of Vienna—even when low energy prices resulted in supports diversity and inclusion principles. Subsidies have a less favorable cost-benefit ratio—have helped to increase the been established for buildings that do not use fossil fuels or refurbishment rate, especially “the quality of thermal insulation that have been built according to passive design principles. post-refurbishment” (SCWFS, 2019: 73). Housing refurbishment Vienna is leading by example, prioritizing the development of also contributes to boosting several economic sectors while district heating and renewables for heating, hot water, and air protecting residents by focusing on vulnerable groups impacted conditioning. by heatwaves (pp. 146 and 154). According to the SCWF, “new stringent energy efficiency and environmental standards are Roofs are underoptimized surfaces that offer valuable space more and more applied in the building and refurbishment for recreational areas or for implementing green roof systems of properties owned by the City of Vienna itself or its related and facades. Green roofs can bring many energy consumption institutions and activities” (SCWFS, 2019: 73). benefits and reduce overall energy consumption if implemented correctly. Therefore, financial incentives have been put in place 5.3 Objectives for buildings and energy in Vienna to push people to implement those solutions. The correlation between energy in buildings is high, contributing A systematic survey will be undertaken to identify suitable to improving people’s quality of life and reducing climate change surfaces in existing buildings and new-build projects. The aim effects. Therefore, Vienna City Council has also defined an array is to optimize the use of these potential concepts, buildings, of objectives related to buildings and energy to track, monitor, and technologies and to implement appropriate measures to and improve their efficiency by 2050. speed up sustainable projects, greening initiatives, and solar energy installations. Among the principal objectives is the goal that energy consumption for heating and cooling in buildings (including Vienna City Council aims to maximize the application of hot water) must fall by 1 percent per annum and related CO2 resource conservation principles by 2030 and maintain them emissions must fall by 2 percent. This is the city’s main priority, as a standard practice in the construction of new buildings and since this energy consumption represents half of the total in renovation initiatives. The impact of resource conservation energy consumption in the city and is responsible for a third of in this context would be enhanced through smart building Vienna’s CO emissions.2 technologies, using digital building information-modelling tools, and optimizing processes. The city authorities ensure that the renovation and the readaptation plan would focus on existing buildings to provide By 2050, the city wants 80 percent of buildings’ components high energy efficiency standards, starting in 2021. In 2018, the to be made from recycled products. The city is aware that Amendment to the Vienna Building Code created the new legal its buildings are a major contributor to CO emissions and2 framework for “spatial energy planning zones.” The amended represent 71 percent of the total waste produced in Austria code stipulates a new requirement: where connection of a new (CVW, 2020). Tackling these issues is a key priority. By using building to the existing district heating network is impossible a renewables-based energy system that incorporates devices (or technically unfeasible), the heating requirements of the new such as heat pumps and vapor-based district heating, Vienna’s building must be entirely covered by renewables. The new code smart buildings are helping to cut CO emissions.2 enforces the use of self-contained and renewable sources of energy. 212 Quélin and Smadja | HEC PARIS | SMART CITIES | The sustainable program of six leading cities | 2021