Office buildings, start your engines. The Green Office Challenge and related IREM Sustainable Property Challenge are underway. Houston Office of the Mayor sustainability manager Lisa Lin tells us the City and IREM are partnering up this year to get whole buildings involved—tenants will work through the Green Office Challenge, while property managers will register in the IREM challenge—both groups will focus on education and outreach, energy, water conservation, materials and waste, and transportation. The programs launched Oct. 1 (Lisa shared this photo from the launching workshop with us) and end in Sept. 2015 with an awards ceremony. (This'll be the first time since 2011 that the challenge officially designates a winner—that year, Brookfield had the highest Energy Star score at 1600 Smith.) Lisa tells us Houston is currently tenth in the US for Energy Star certified buildings.