After a couple of efforts to sell its current office stalled, the South Pasadena Unified School District has taken out a loan to close escrow on the new building it agreed to purchase last year. Meanwhile, the district announced it has entered escrow with a development firm that has tentatively agreed to purchase its longtime home. The SPUSD Board of Education pulled the trigger on the loan last week, around a month after agreeing to modify its purchase agreement for the new facility, located at 1100 El Centro St. The district is borrowing $11 million, at 2.48% interest over 20 years, with an option for early payment after it sells its current headquarters at 1020 El Centro St.