Multiple services per appointment

Hey folks

So I want to create a website that allows people to book cleaning appointments for their homes. I want to charge by room, so if there's a kitchen, 2 bedrooms and 1 bathroom I want to be able to make a booking based on that price. I'm not sure how to accomplish this. I think I should be breaking rooms and then the number of them each as separate services, but I can't figure out how to select more than one service or type of services at the same time.