Can the GSA Go Zero Energy? Part 1 of a Conversation with AutoDesk's John Kennedy

Q. The U.S. General Services Administration (GSA) has said their goal is to get their buildings to zero environmental footprint. Is that doable?

A. It depends what they mean by zero environmental footprint. If it is a zero energy building (ZEB), then yes, it is doable for a very large percentage of their buildings.

The National Renewable Energy Laboratory (NREL) conducted a study for the Department of Energy (DOE) to determine the potential commercial building floor area that can reach a ZEB goal, and found 47% of commercial building floor area can reach a ZEB goal.

This study is also conservative as it did not include natural ventilation or some of today’s newer technology for windows as part of the measures to take to make a building efficient. Including water use as part of the zero environmental footprint is harder to achieve due to technology acceptance and know-how of gray water systems and rain catchments.

Q. How can they reach this zero energy goal?

A. Making an existing building a ZEB is a multi-step process. First, is understanding that the building will need onsite renewable generation of some form to power the building and making the building as efficient as possible will reduce the size of this system.

For instance, it takes about US$7,000 of Photovoltaics (PVs) to power a hair dryer (1000 watts). So, if I purchased a more efficient hair dryer, say one that does the same task for half the power (500 watts), I just reduced the amount of PVs by half saving $3,500 in PV costs. This same analogy applies to the building’s systems.

In order to determine what actions to take to make a building energy efficient, a whole building energy analysis needs to be conducted, which traditionally costs tens of thousands of dollars and weeks of work.

With today’s Building Information Modeling (BIM) solutions such as Autodesk Revit MEP and Autodesk Revit Architecture as well as sustainable design tools that use the green building XML schema, this task can cost effectively be done on most existing buildings in less than a week.

These solutions not only determine the actions to take in making a building energy efficient, they also estimate the carbon emissions, the total renewable energy generation using PVs and wind on the site, as well as water use in the building and the amount of rain water that falls on the building in a year. These analyses can very quickly allow someone to determine how feasible it is for their building to be a ZEB or carbon neutral.

Autodesk has also recently developed a Rapid Energy Modeling approach for owners and their consultants to cost effectively use these tools on existing buildings, the approach was defined based on Autodesk research on existing facilities using solutions in the portfolio today.

Rapid energy modeling is a streamlined process that involves moving rapidly—and with minimal data—from image capture of building exteriors through simplified simulation to building energy analysis. With the ability to apply these analyses through a rapid energy modeling process to a large number of buildings the GSA can assess which buildings they should invest in to achieve their energy and carbon reduction goals for 2012 and 2030.

Image courtesy of cliff1066 via Flickr