I'm trying to model an iPhone. I have made the base shape for the phone by using a cube with subsurf modifier. Im now trying to make a button on the side but I cant do this without adding loop cuts and this affects the shape of the phone due to subsurface. How can I make a button as seen in the picture to my model while keeping the rounded shape the same of the current model?
You need to add some geometry to your mesh. Then add some edge loops around with some bevels and ctrlR, delete faces, extrude, move a bit the edge loops you've created to make the hole round, and extrude inwards. To make the button just duplicate the hole profile and extrude.