Or keep the greenhouse?

I think it's depends on what you want to accomplish. Do you want an open outdoor scene or a greenhouse? They both look good.

Agreed. They both look good. What do the lighthouse keepers prefer? I suspect keeping a lighthouse can be a lonely profession. Maybe they need the activity provided by maintaining the greenhouse. 

Lighthouses are often in places that are windy, with a lot of saltwater in the breeze.  A greenhouse might allow the keeper to grow more and different kinds of plants, as well as provide a pleasant, sheltered place to be "outside" on a windy day.  I vote for keeping the greenhouse.  (Plus, I just like the way it looks.)

I am loving this