I use Gile[s] to lightmap most of my scenes and find glass is quite easy to re-create.
Here I've used a small greyscale texture stretched over the glass faces.
The texture is set to Color, Alpha and Mipmap.
The Texture blend is set to additive.
The material blend is set to alpha and No lighting.
Full bright, flat shaded and two sided flags are on.
Cast shadows is off..
It looks like glass to me.
You can get different effects by changing the blend mode for both the texture and the material.
Here I've used a small greyscale texture stretched over the glass faces.
The texture is set to Color, Alpha and Mipmap.
The Texture blend is set to additive.
The material blend is set to alpha and No lighting.
Full bright, flat shaded and two sided flags are on.
Cast shadows is off..
It looks like glass to me.
You can get different effects by changing the blend mode for both the texture and the material.