Sweet Home 3D is a brilliant choice for making interior design and house sketches. And you could import models of horses and soldiers to visualise a battle scene. However, while SH3D is easy to use, a battlefield is pretty far away from home design/improvement - and SH3D probably not the ideal choice.

You could take a look at Blender. Harder to learn (instruction videos are quite useful), but there is a large user community and lots of options for making very advanced 3D stuff.

ok