advanced rendering for AutoCAD
Don't use HDRI with interior renderings. Sun and daylight will be quicker to resolve and give you a better result.
Tag window glass as daylight source, not curtains.
As Roy said, try to keep your materials simple.
If you're using daylight only, you may need to increase the number of indirect bounces.
One immediate thing I notice with the model is that your viewpoint is from outside the building looking in through the window.
You need to move inside the room.
With flat materials such as emulsion paint and vinyl wallpaper, add a bit of glossiness using the glossy shader.
Very few materials show perfect reflections, so I would suggest you turn down the reflection sharpness on your floor and wood materials.
Make window glass perfectly clear and perfectly reflective. Model it as a region and tag it as thin.
For the curtain material, I would forget all the masking etc. Just give it a tiny bit of transparency and a lot of blurriness.
I'll post a render and updated model in a short while.
A couple of other things:
The architrave round the edge of the ceiling doesn't fit properly.
The skirting round the edge of the floor is partially enclosed in the wall and has the same material as the floor.
The glass in the double doors isn't tagged as a daylight source.
I'm not sure why there are odd reflections round the edges of the floor. I'll see If I can track it down.