I've added lights to my window as my orchids were not getting enough light. A tree shading my window keeps growing. There are light meter apps for the iPhone. If you know a little about photography, you can use them to estimate how much light each plant is getting. Ray explains how to do it on his site.
Orchids let you know they're getting too much light with warm leaves and sunburn on leaves. When there's not enough light, they won't bloom. I got a light meter app to make sure I had blooms after a year of taking care of them...and I do like numbers
. Being that your fiancé is an engineer, he might like the light meter app.