When renovations to a Federal facility are extensive—either a full building addition or taking the original facility down-to-stud and rebuilding it entirely—the process is much closer to the design process for new construction. In addition to other recommendations in this guide, however, there are a few ideas to keep in mind when adding renewable energy into the renovations.
Although some elements of design are constrained, such as building site and orientation, an extensive renovation provides a wide range of opportunities for whole building design and integrating renewable energy. As noted in other areas of the guide, energy plans should be included early in the planning phase, and goals should be defined and included as part of the design programming.
With a building addition it is important to think outside the box—literally. The energy improvements or renewable energy incorporated into an addition can be used to provide energy to not just the addition but the entire building. When assessing the renewable energy options, the entire facility, not just the addition, should be included to determine the optimum types of energy technologies to incorporate. For example, it might make sense to include a geothermal heat pump with the new addition that has enough capacity to heat, cool, and even provide hot water to the entire facility.
Also investigate whether the new addition will warrant any changes to the existing building structure or systems to afford opportunities for further integration of certain renewable energy technologies.
As with a major renovation or new construction, energy modeling of the planned facility is important to make decisions about the best technologies and designs to select. The modeling on a building addition is more complex, but the addition should be modeled in such a way to take advantage of the benefits to the existing facility as well. Additionally, the life-cycle cost effectiveness of renewable energy technologies can be analyzed as both stand-alone systems for the addition and as fully integrated with the entire facility.
At times, a facility will be entirely gutted, with the renovation encompassing every system of the building. Whether the footprint changes or not, this type of renovation again closely mimics new construction, and the building design can revise the entire layout and building systems to dramatically reduce the building's energy needs. To be successful, energy reduction and renewable energy technologies need to be a clear part of the intent of the renovation and specific energy targets should be specified prior to selecting a design team.
Down-to-stud renovations should be approached in a whole building design perspective and designed as a holistic facility rather than the renovation of a series of sub-systems. This type of renovation can be very innovative—for example, the Byron G. Rogers U.S. Courthouse in Denver, Colorado, renovated a historic building and incorporated a range of energy savings measures to earn an ENERGY STAR® rating of 87.