According to the EPA buildings are responsible for up to 40% of all energy usage and carbon dioxide production, because of the increasing need to decrease energy usage and the US carbon footprint more stringent building standards are being put in place based on ASHRAE 90.1-2007 with some states adopting stricter standards. Each state energy code is available here. Massachusetts had adopted one of the stricter standards and just wading through the stuff makes your head spin, I got sidetracked researching it by a thread discussing compliance concerning a sunroom and if it had to be added to the total exterior wall footprint of the house, and then there were tables with insulation factors, etc. To add to the madness there is the HERS (Home Energy Rater System) system developed through energy star, and the ResCheck Suite developed by the DOE that ‘helps’ with home compliance. Maybe you’ve started laughing by now or more likely crying. All of this is well meaning but will take even more specialists to wade through it, understand it and comply with it. Wouldn’t it be nice if there were plug in components for energy analysis with BIM software..wait a sec, they got that, and then run scenario analysis so you can see what modification or additions you need to make to comply to this new and evolving standards, have the software figure it out so you can design and build. Use a swiss army knife instead of a spoon.