For a window sash like this, just a little moretexture and detailI would like to add 

The current situation tends to be a low-poly model like this... 

I would like to make a model like this. 

Add texture and detail 

It takes a little more work, but the sashvertical materialWhenHorizontal materialseparate the models. 

The vertical material has the local Z axis aligned in the vertical direction.set to 

Weft material is laterally aligned with the local Z axisset to 

Tools->Options->OriginsIf you check the box, editing the local axis becomes easier. 

bevel modifierIf you add , you get closer to a more realistic expression. 

Boolean modifierand subtract the glass object,part to fit the glassis created. More seals are actually added, but omitted here. 

At the endset materialTo do. of each sashhairline stretches with respect to the local Z axisI have a setting like 

This is the image.

That's all. The details of the sash were added, and I think the texture was emphasized.