Is it even possible? Yes. Take a look at this ladies and gentlemen! This is the EDITT Tower. Ecological Design In The Tropics. This is being built in our neighbour Singapore. It will be covered by organic local vegetation and includes solar panels which will generate up to 40% of the building's energy demands. Even human waste will be converted into an energy source. Not sure about any future negative result/side effects or any sort of those things. See for yourself though.