Read this article on 10 business trends facing builders;  http://www.builderonline.com/business/a-year-of-recovery_1.aspx
Most are positive economic recoveriy trends but there are some that builders have to be watchful about and those are about changing demographics, market patterns towards multi family homes, smaller houses and ofcourse the rise of global awareness towards energy conservation and preservation. The trend that caught my eye was the rise of affordable NET Zero builders. read more...

Heat rejection is a prime concern with distributed residential AC as described in this website. Ideally, I like to be able to reject heat to geothermal water cooled system. The design and implementation of this has significant impact on residential construction and building codes. I like to get feedback from building professionals. Geothermal water cooled system requires a PEX pipe circuit running throughout the house. The reason is that in a typical house of 2500Sq. Ft there are about 20 smart microAC units located in almost every wall in the house. This requires water to be circulated to almost every wall in the house.