- Higher up front costs - long payback periods
- Need for proper commissioning (this means you need to make sure the equipment gets installed and adjusted precisely - or it will not work properly). If not installed and adjusted properly it can actually lead to higher energy costs.
- Need for ongoing maintenance / adjustment which leads to higher maintenance costs. If not maintained properly it can also lead to higher energy costs.
In general the more sophisticated the equipment the more potential headaches. I have seen other studies that compared the energy use of LEED buildings vs. their non-LEED counterparts. Guess what? - the non-LEED buildings were just as energy efficient as the LEED ones.
So the moral of the story is to keep things simple. Favor envelope improvements and good passive design techniques (see my posting: top 10 green things to do) over sophisticated appliances / equipment.
Click the following for the full Green Building Advisor article: SIMPLICITY VERSUS COMPLEXITY