Recycling and reuse of structures and elements is important to reduce the carbon footprint of the building industry. Reuse requires much less energy than recycling and therefore has much potential. However, reuse is still rarely put in practice due to the many challenges constructing with reuse involves. One of these challenges is the complex design process. In this research, I have developed a tool able to design with reused elements. Topology optimization is combined with reclaimed elements with the aim to simplify the design process for steel truss structures. The member adding scheme of Linwei He. et al (2019) is used as a basis. Adaptations and additions are made to include geometry information and limited availability of reused elements. In the final tool, capacity utilization of elements is maximized, material volume of the structure minimized and percentage of reused versus new elements maximized. In conclusion, discrete topology optimization proved to be an effective method to simplify the complex design process. The tool can generate multiple different designs for every optimization problem with limited complexity. Volume increase or decrease compared to standard designs depends on availability of elements. In examples in this research volume increase could be limited to 20-30% with limited availability of elements. With large availability, multiple different designs could be obtained with an average unity check close to the maximum unity check. Recommendations are to improve applicability of the tool and to make an estimation of the reduction in carbon emissions and construction costs compared to designs with new elements. These estimations could increase attractiveness of designing with reused elements. Finally, accessibility of designing with reuse should be increased. It should be less difficult to obtain data of existing buildings planned for demolition to experiment with designing with reuse.