In most cases an architectural visualization project will require some objects carefully placed at the scene, to give a sense of scale to the image and to demonstrate how the scene will look like when the project becomes real. And to use furniture in architectural visualization you could simple take the model from an online library like BlendSwap or create your own. I really love BlendSwap when you don`t have enough time to create your models, but it is always a good idea to create your furniture objects.
This way you will be practicing your modeling skills and take full control of polygon count and topology of the objects at your scene.
If you never had the chance to create a furniture model, here is your chance. The tutorial below will show you a basic procedure, on how to create a sofa in Blender. The tutorial is simple, but could guide a less experienced user on how to create a basic sofa.