Complex sentence: UMUC retrofitted its new headquarters to meet "green" building requirements for LEEDS certification as it did to achieve LEEDS certification in 2005 for its Inn & Conference Center, which became the first hotel complex in the United States to achieve certification as a green building.
Split into simpler sentences: UMUC retrofitted its new headquarters to meet "green" building requirements for LEEDS certification. UMUC followed the same process as it did to achieve LEEDS certification in 2005 for its Inn & Conference Center, which became the first hotel complex in the United States to achieve certification as a green building.