[wott]

> In hot or cold weather, transit emissions savings may be more than offset by increased HVAC usage at home.

Most people keep on heating/cooling their home while they are at their office; sometimes to a lesser power, sometimes the same all the time. Office which is also heated/cooled (and had to be built one day, often terribly). So with a regular job, your home emits, your office emits at the same time, and the transportation between those emits too (and had to be built).