The surface constructed when a user draws a closed loop in a single view is assumed to implicitly enclose a volume with the base layer. We construct a volume automatically by constructing new surfaces between the base layer and newly constructed surface. This type of volume can also be constructed with any surface by clicking on the surface while holding the ctrl key. An enclosed volume is not always desired, so we provide an extrusion technique for creating volumes as well. While holding down the ctrl key,the user sketches a normal curve starting on the surface acting as the base of the volume. The volume is then extruded along the normal curve.