I'm also always struggling with a correct way to formulate this number. Most reports will cite IEA report which says something like "construction and operation of buildings are responsible for 38% of global emissions" (note "construction"). This number is usually the one you'll see during ESG presentations.
Also "of buildings" not simply "commercial buildings".
Either way, the implication that operation (ie day to day running) of commercial buildings in the US might make up the order of 40% of global C02 emissions seems a stretch.
FWiW I'm all for aggressively cutting back total global greenhouse emissions and have been since the 1970s (I've worked for decades in Energy | Minerals geophysical mapping and exploration and assisted developing world scale GIS mapping systems since the late 1980s (about a decade prior to Google maps IIRC)) and that's going to take some hard to swing lifestyle changes by the larger per capita emmitters, buuut that's also going to take some realistic lining up of priorities and reative emissions.
That aside, good to see changes being made in the commercial running costs domain .. all moves to shift the needle downwards are good.