Re: I am trying to design an 8-storey steel project idecad ka Hello; There are slabs in the air in your project, apart from that, composite slabs are defined in the stair landings section, there are only 172 tiles in your project. Therefore, not your computer, the project is quite heavy and slow, it is not possible to end the slowness without correcting modeling errors. If you are keeping the .bak files of your project, can you share the state before the slab definition and staircase creation process? Good work.