These guys have a company that manages building maintenance. You just give them a call and... pay, and voila, you don't have to worry about the building you live in, ever again. They make sure that everything is clean, all the lights are working, elevators are always fine and running, the roof is not leaking, the building is not on fire etc. :)
A small one - not much functionality - straightforward site full of precise, no nonsense information. Easy right? They needed a site that gives answers to their potential customers because they were receiving tons of calls and most of the people were asking the same questions. The challenge was to pack all those answers in a non overwhelming manner, with no space for misinterpretation and make it available on all devices. We ended up spending most of the time doing copyright and reading trough laws. Not easy at all! So when we finally got to the stage of designing and coding, it was a breeze. :)