Calpine Center, Postmodern skyscraper in Downtown Houston, United States.

Calpine Center is a modern office tower with 33 floors located in Downtown Houston's central business district. The building rises prominently with a glass and steel exterior that defines its contemporary appearance among the surrounding structures.

The building was constructed in the early 2000s and opened in 2003, marking a new chapter in Downtown Houston's development. This period represented when the city was modernizing its core business district with contemporary office space.

The tower's name comes from Calpine Corporation, an energy company that took 250,000 square feet and keeps its world headquarters in the building; Burlington Resources, another energy firm, signed for the same amount. Jones Day leased over 50,000 square feet, and Cheniere Energy was among the tenants at the November 2003 opening.

The building connects to Houston's underground tunnel system, allowing visitors and workers to move between downtown structures while staying protected from weather. This network proves especially useful on hot or rainy days when surface navigation becomes uncomfortable.

The building features more efficient space design compared to many older office structures in the area. These improvements in floor utilization reflected a broader shift toward smarter office planning in the city during that era.