I lived in a three story house.. washing was a pest.
bedrooms on top. laundry on middle level.. line on the bottom level!
I feel like i have cracked the laundry hamper thing here! AT LAST... no prizes for guessing it was an IKEA solution LOL
Ikea Antonius. I bought the taller slider shelf cabinet
http://www.ikea.com/au/en/catalog/products/90177631
and three of these
http://www.ikea.com/au/en/catalog/products/80177603
The top one has lights, the second one has darks and the third one has heavily soiled clothing (or delicates/woolens) (or towels) depending how your family live and their needs.
You simply slide the basket out and carry it (easily because it isnt HUGE or heavy!).. to the washing machine. A full basket is a full load in a 7 / 8 kg washer.
NO more sorting laundry. You have a basket to carry that has handles and isnt a nightmare. You can safely do stairs etc. You even have a basket ready to use to hang the clothes or take them to the dryer etc.
It is plastic, it doesnt smell and is easily wiped over! Socks and bits don't go missing and it fits into a bathroom or WIR easily. I find putting the hamper where the people get naked is key to them putting it in the hamper. NOT very likely that someone will shower and change and carry their clothes downstairs and file them accordingly, in a cupboard. ?? or your family can come and train my family LOL
I find the boys will put their clothes in the right hamper when there is only two choices tho.