One of my esteemed colleagues, Greg Allen, is a "sustainable strategist" in HOK's Toronto office who specializes in energy. Seriously, this guy knows everything about it... non-renewable, renewable, anything you want to know. I ask him all of my obscure energy-related questions that noone else knows the answer to... like about co-gen, solar nano-technology and if T. Boone Pickens really knows what he is talking about.
Greg has just written a really nice white paper about retrofitting buildings currently reliant on fossil fuels (that means most buildings). It's a very helpful resource if you're looking for ways to seriously change the way your building uses energy and, in fact, create revenue by selling energy back to the grid. His answer is NOT just slapping solar panels on the roof. Be prepared, it's a complicated answer, but worth really understanding.
For the short version of his paper, click here.
For the long version, click here.