The actor no longer lives at the property on Woodrow Wilson Drive but rents it out.
The blaze broke out on Friday night (09Sep11) and firefighters fought to contain it. Two suffered heat exhaustion in the effort and were taken to hospital.
The cause of the fire has yet to be determined.
The Los Angeles Times reports two unnamed actors were renting the home from Nicholson at the time of the fire. Nicholson hasn't lived at the home since 1995.