Idea: Lift buttons at entrance

Ok. So here is the idea- for buildings that have relatively large corridors, why not have the buttons to call for a lift near the entrance too?

The reason I'd do this is simple- there are a lot of times I enter my building and see people boarding a lift and they move before I get there. If I could stop the lift from/near the entrance I could not use the lift again- and hence save power..what say?