Architectural Designs

How much should I charge to do interior design for a one bedroom apartment?

So heres the deal. I'm not an interior designer but I am a professional artist, and I just did a painting for a client. He asked me to redecorate his entire apartment. Anything I want to do, I can. Now I have no idea how much to charge him (on top of costs). This would be a major undertaking-hiring helpers, cleaners, movers, ect. Should I charge a flat rate or by the hour? And how much? Has anyone recently hired an interior designer? how much did you pay? This has all been really helpful. I'd like to add some details thought. I don't charge hourly for paintings. Just a flat rate, I recently charged $5000 for a painting plus $500 for supplies. This particular fella doesn't know the going rate for interior decorators. I made a comment about his apartment and he said he wants me to decorate it and I said I would think about it. I mostly want to hear that it's okay to charge 5000 to 7000 plus materials to completely decorate his apartment. I'm talking everything from the kitchen to the bathroom. Steam cleaning the carpets, painting the walls and trim. new dishes. maybe even new clothes. Thanks for the answers so far everyone!

Public Comments

1. Falt fee will get you in the back unless they do the pre work moving soaf's ect. By the hour you could be blamed that you are milking payment. Flat fee they move the rooms clear ... They buy the paints ect and you think about how ong it will take you and charge the price you would get if you were doing a art job . What you were paied in the past for art. Less than 900 sq. feet go for $1500.00 don't be shy go for it It not as easy as you think
2. interior designers can charge by the square foot or hourly the minimum hourly rate is around 65$ an hour for a first timer I would suggest hourly and they foot the bill for materials and supplies that way you still make a profit seeing as you dont know how much time you will be in there working...
3. should consider the size of the apartment ... i think the best way is to charge in 1 package, not per hour- lets say, around 3K for small apartment?!