My Grandpa* used to store his bikes in the kitchen. My brother hung his road bikes to the wall over his bed when he still lived in his student appartement.
The appartement building I'm now living in in Berlin has a bike storage room just besides the basement garage - however, more people seem to use the bike than planned, so it's always overcrowded, meaning I store the bike in the basement (which actually is earth-level because the parking is underground... so that is even more convenient). In Munich we store the bikes in the basement. When i bought my wife's bike, I paid attention to it being lightweight - meaning aluminium frame and good quality components. So carrying the bike upstairs is rather conveninent even for a not-so-strong woman.
Storing your bikes outside is entirely possible, but requires that you really do maintenance them. Keep your chain clean and regularly lubricated, as else it will rust in nearly no time, and a rusty chain and gears will not only be prone to premature wear, but also require much more effort!
You can rust-proof a steel frame, my mountain bike got a healthy dose of fluid film inside the tubes... I also use spray wax to protect paint and parts like handlebars, brakes, wheel hubs. All of this ist rather cosmetic and to keep the bike looking good. Steel bike frames are made from very high grade steel that rust only very slowly and sparsely. I have never seen a frame rust to the point where it's structural integrity might be endangered.
Bike racks like the one linked above have one severe disadvantage: they put severe stress on your front wheel and might even bend it. It's always better to use the bike's side stand (if it has one) or to just lean the bike against a wall, lamp post or similar.
I saw a nice solution for an appartement building last weekend: bikes stored outside on the sidewalk and chained to the house. The landlord had fastended eyes to the facade and put a steel rope through - tenants could then lean their bikes against the wall and lock their bikes to the steel rope.
*Mustachian by fate - he lost his job age 55 and could not find another, having been severely wounded (lost one eye because of grenade fragment in head, right hand crippled by a bullet and some more), so he just lived of his stache - while growing it to a point where he was able to donate frivoulous amounts of money for our university education while maintaining his apparently very bourgeouis standard of living. Despite of his crippled hand and his lost eye, he built half of the furniture in his appartement himself (and if you didn't know, you would never notice), built a lot of our small-child wooden toys and entered in road races, even taking part in the cycling world cup in his age group.
