Boca Raton-based law firm Proskauer Rose signed a new 10-year lease at its current building but will change its space. It will combine offices on parts of two floors into one, increasing its size by 34,000 feet at One Boca Place. The firm will occupy one-eighth of the 277,000-square-foot building at 2255 Glades Road. Asking rents at One Boca Place are currently listed at $24 per square foot. Boca Raton currently averages $19 per square foot, with a vacancy rate of nearly 30 percent, according to CB Richard Ellis research.