The construction industry plays a crucial role in promoting more sustainable development and reducing greenhouse gas emissions. Concrete is the most commonly used building material and its manufacturing is a significant source of carbon dioxide emissions. There are many ways to reduce the climate impact of concrete, and one such method is topology optimization.  This study investigates how topology optimization can reduce the carbon footprint of concrete foundations. To do so, a comparison will be made between a topology-optimized foundation and a non-optimized foundation made of climate-improved concrete to evaluate their climate impact. The study aims to assess the sustainability benefits of the optimized foundation in order to promote a more sustainable construction industry.  To investigate this, a literature study was conducted first to understand the subject and plan the project. Then, RFEM modeling and manual calculations were performed to obtain values and geometry of the foundation. After that, the foundation was modeled and optimized in FreeCAD using a Python code.  Through topology optimization, the mass is reduced by 60%. The difference in CO2 equivalents was found to be 52% between the topology-optimized foundation and the original foundation, while the difference in CO2 equivalents was 40% between the climate-improved foundation and the topology-optimized foundation. This leads to reduced material costs and reduced carbon dioxide equivalents during manufacturing. This can also have positive effects such as reduced energy demand and reduced waste. However, it is important to note that the optimization process depends on correct boundary conditions and that the optimization algorithm does not take into account practical limitations, which can lead to suboptimal solutions.  In conclusion, topology optimization can be a useful tool for creating efficient and environmentally friendly solutions in the construction industry by using topology optimization as a means to identify where in the foundation material can be reduced, which in turn reduces carbon dioxide emissions and promotes a more sustainable environment.