My commute varies from 8km to 25km each way depending on schedule, weather, bike choice etc. I have showers at work so am able to get changed easily. For commuting I have 3 short sleeve jerseys, 3 long sleeve jerseys, 3 pairs of bibs, 2 pairs of 3/4 length bibs and 1 pair of bib tights. Added to that, arm warmers, a windproof gillet and a waterproof jacket, plus gloves and too many caps. This means I can put stuff through the wash every couple of days rather than daily.
Even with a short commute, my view is that I am better/more comfortable riding in proper cycling gear, knowing I am going to have to get changed at work anyway. Cycling kit also dries way quicker so if you have access to an airing cupboard/drying room.