In 1997, 21,000 new seats were added to the stadium, bringing the seating capacity to 80,795. After the 2014-2017 Campus Crossroads renovation, the seating decreased to 77,622. There has never been any advertising or corporate signage allowed in the stadium, and the decorations are simple and traditional. Notre Dame explicitly tried to maintain the look and feel of the stadium in line with the original stadium built by Rockne in the 1930s. Field The playing surface had always been natural grass through 2013, but it was announced on April 12, 2014, that after the commencement weekend, the playing field would be replaced with an infilled artificial turf. Notre Dame athletic director Jack Swarbrick, in making the announcement, cited recent difficulties with maintaining an acceptable grass surface, and added that the change would allow the stadium to be used for football practices and non-football events. During 2013, the university replaced the grass surface four times, including twice during the football season. The artificial turf installation, as scheduled, began after Commencement Weekend on May 16–18, 2014, and the university sold sections of the old turf to the public for $150 each. The decoration of the field is minimalist and traditional, and has changed little since 1930 and the times of Knute Rockne. Unlike most football stadiums, the end zones do not feature the name of the school or team. Each end zone is painted only with nine diagonal white lines, for a total of 18, each at a 42 degree angle and pointing towards the Golden Dome. This is symbolic of 1842, the year in which the university was founded. This design was used in 2014 when FieldTurf was installed, but a similar design has been used since 1930, when each end zones features 30 diagonal white lines. The renovation in 2014 also saw the addition of the ND monogram, symbol of the athletics program, at the midfield, and small green shamrocks at the 35-yard. No other decoration is present on the field, expect for occasional logos as for the 150th anniversary of the university in 1992. Lighting Prior to the 1997 expansion, Notre Dame Stadium lacked permanent field lights. In 1982, portable lighting by Musco Lighting was used for the first night game in the stadium's history on September 18 versus Michigan. Permanent lights were installed as part of the expansion. The lights were paid for by NBC, which has held