Viewing post #524354 by Swayback

dave said:Not at all. UV rays are not helpful to plants, as far as I know. Greenhouse panels are specifically coated with UV blocking filters so your windows would be just like the effect produced by greenhouses.

I had always heard the opposite...
* puts on his homework hat*

I do know that glass "eats" light! As does greenhouse film and polycarbonate panels.
Somewhere is the range if 8%-20% of light will be lost to EACH layer, if your windows are modern double pane, then that's 2 layers...

Also dust and the like on windows will eat a small, but ever increasing amount of light.

For many houseplants, this is not a bad thing, for some, it is!