What frequency buys and what duration buys
Frequency buys currency. Washrooms, kitchens, bins and entry areas are judged on their condition at any given moment, and no amount of thoroughness on Monday helps them on Wednesday. Duration buys depth. Floor detail, skirtings, internal glass, behind and beneath furniture, and anything that needs equipment set up and put away all require an uninterrupted block of time that a short visit cannot provide. Most buildings need both, which is why the pattern matters as much as the total hours.
The practical question is which failure your building suffers first. If complaints are about washrooms and bins mid-week, you have a frequency problem and longer visits will not fix it. If complaints are about grubby edges, marked glass and floors that never look properly done, you have a duration problem and adding a fourth short visit will make it worse by spreading the same hours thinner. Diagnose before comparing.
