Firstly, when you use an HDRI, you usually should turn off the SketchUp sun. That way the lighting comes from the HDRI and matches the background.
Second, the glass windows can use a bit stronger reflection value.
Third, the grass would benefit from using VRAY fur or something else like Skatter.
Here’s a post I did recently about a few simple steps to improve VRAY renders: Sketchup plus Vray - #11 by eric-s
Otherwise nice first attempt. Way better then when I first started learning version 1.5 a while back.