I asked skynet:
In a low-poly room, the average polygon count typically ranges from 500 to 5,000 polygons, depending on the level of detail and the purpose of the model.
Very simple low-poly rooms (basic shapes, minimal details): around 500–1,500 polygons.
Moderate detail (furniture, more complex shapes, a few decorations): around 1,500–3,000 polygons.
More detailed low-poly rooms (more intricate furniture, decorations, and features): up to 5,000 polygons.
Staying on the lower end is ideal for game design or real-time applications, while the higher end might be more suitable for renders or less demanding projects.
Yeah! There is no average we can give you. It depends on the number of objects, the type of objects, how many windows...
So many things will determine the number of vertices your room will have.
The best option is to take each object one by one, modeling as low poly as possible without degrading the shape and maintaining a good silhouette.
How many vertices your room ends up with is entirely in your hands.
I'm currently working on my submission for this course; my scene statistics indicate I'm already at 695 triangles, which is the basic unit of polygons, and I haven't started modeling anything beyond the structural components of the room, so I'm curious to see what kind of poly count I rack up myself, because currently my scene is very clean, in my opinion.
Viewport Editor Screenshot
I like the beginning of your scene, lots of possibilities. When I got finished my poly count was 17,625 for Faces and 36,257 for Tris. I referenced pictures on Thuma's website for the bed, dresser & nightstand. The bed had the most objects to model.