The construction site was initially intended for two separate buildings, and the annex was to be built with lower ceilings, and simple heating and ventilation systems, because it was designed to house offices rather than classrooms. Reinforced concrete was used in construction because "granite was no longer a viable facing option." The Dwinelle Expansion Project was begun in 1996 and was completed in 1998. The project included the addition of two new floors to the office block, cost $10 million, expanded the building about 20%, and required the temporary removal of the roof. Dwinelle is frequently referred to as the "Freshman Maze" because of its confusing architecture. Soon after the building's construction, according to author William Rodarmor, students would "enter Dwinelle in their freshman year and emerge, blinking in the sunshine, just in time for graduation." As it was constructed on a slope, there are separate entrances to the building that connect directly to the first, second, third, and fourth floors. Classrooms require higher ceilings than offices, so the two wings' floors do not match up. On every floor, there is a hallway or staircase to connect the classroom wing to the office wing, and it is possible, positioned in certain areas of the building, to view five staircases, two elevators, and four hallways. The office wing consists of seven floors, A (bottom) through G (top). There are exits on levels A and B. Level B has access to Ishi Court, a courtyard in the center of the office wing. Offices have four-digit numbers. The 1000s are located on level A, the 2000s on level B, the 3000s on level C, etc. There is also an attic area in the office wing. The classroom wing consists of five levels, B through F. There are exits on levels C and D; level B is underground. Levels C, D, and E in the classroom wing connect to levels C, D, E, and F in the office wing. Level F in the classroom wing connects directly to level G in the office wing. Classrooms have two- or three-digit numbers. Classrooms on level B have numbers beginning with "B", such as B55. Classrooms on level C have two-digit numbers. Level D consists of the 100s, level E of the 200s, and level F of the 300s. Cal Dining operates the Common Grounds cafe on level F of the classroom wing.