Hi Cirillo,
You are in the similar situation to me and that is that the house shades a major part of the lawn during winter and over a period of years the lawn just won't be able to handle it. What will happen is that you'll end up with fungal type issues within the root system and that's basically cancer of the lawn. I know that in time I'm probably going to have to deal with it also but until then I'm going to do my best to keep it's health in the best shape.
It would be good to have sun tracking mirrors that reflect light back onto the lawn, but hey this James Bond technology isn't going to happen for me.
Cheers,
BB.
