[deltarholamda]

HVAC has to account for the BTUs produced by all equipment. An office might have one or two refrigerators per floor, maybe a dishwasher. Apartments will have one in every apartment. Ditto for ovens, dryers. Even computers and TVs.

[ArchitectAnon]

Offices have a lot more people per m² all of them using computer equipment continuously for 7hrs/day so in my experience they tend to have considerably higher cooling loads. I know from experience that a typical high rise office building in London, UK will have no heating requirement for most of the year; it is in cooling mode most of the time.

[deltarholamda]

You have to account for peak usage, not median. At 7AM and 6PM, everybody has their stove or ovens going to make dinner, plus the washing machines and dryers.

Building codes and practices are different for commercial and residential for good reasons.