How to throw my boyfriend a surprise party?!

My boyfriend and I have been dating for about 5 months and his 17th birthday is coming up. I wanted to throw him a surprise party. I have about 25 people on the list and a few dates up in the air of when I can do it. My problem is... I don't know where to have it. I think it would be easiest if it was at his house maybe a night when he gets home from work (usually he gets off around 7pm) and his bedroom is in the basement so I figured we could all hide in the basement and when he comes home to change or whatever go to his room, we yell surprise and yada yada yada... Would it be rude though to ask his family if I can host this party at his house with 25 people? Do you think they would feel obligated to say yes? Anyone got other suggestions on where I could have the party? HELP!