Can I re-furbish my shed when the house i own is rented?

Im doing up my shed, like cleaning it and re painting it and cleaning the rust off the roof, but am I alowed to or do I need permission from the house owner? I have been renting the house for a few years and the shed is a garbage dump and needs to be cleaned. I dont see why I would need permission i am not making any major changes. I am just repainting it the same color and cleaning the rust and filth from it.