The RC-CLT Hybrid Sveta Ana is a reinforced concrete and timber structure featuring a combination of RC walls and cores with timber CLT panels. The building is 40.2m x 17.25m and rises over four levels, including a basement and two upper floors constructed with CLT walls and floor slabs. The reinforced concrete core provides seismic stability and houses staircases and elevators. Timber CLT panels, 10cm thick, form the exterior walls of the upper levels, with additional internal timber frame walls providing support. Steel beams and columns supplement the structure, particularly in areas with cantilevered slabs. The basement and ground floor are constructed with RC walls, columns, and slabs, ensuring robust load-bearing capacity. Seismic resistance is achieved through the reinforced concrete core, supported by ductile detailing of walls and columns, while the CLT and OSB panels dissipate seismic energy in the upper levels. The structure is founded on a 45cm RC mat slab designed to withstand concentrated loads and provide stability on varying soil conditions.