Emma Watson has yet to spend her Harry Potter fortune on a place to live because she fears buying a house is "really grown-up".

Watson, 23, made millions from her role as Hermione Granger in the wizard franchise along with her castmates Daniel Radcliffe and Rupert Grint, who have both poured their money into extensive property portfolios.

However, the actress admits she hasn't purchased a single home and is currently renting an apartment in London.

She tells Britain's GQ magazine, "It's madness, I know. It's really silly... I really should do something about it. But it's like my choices with everything. I just always have to be sure it's really something I want... There's a big thought process that goes on behind everything... I guess it (buying a house) just seems really grown-up."