Martin, that's a green house your on about lol. You'll be surprised at how much light is getting in with just that one window. I'm hoping we will have some sort of decent weather, where I can have the door open when working, but don't mind having to put the lights on when required. I was contemplating putting 2 sky lights in at a later date to allow heat/light in. But I'm concentrating on getting the bulk up and running first. As I say I'm always willing to listen and learn. After all, this the work of a diyer lol