By Andrew L. Shakely, PE, LEED AP, Vice President / NuTec Design
Ever since it was pioneered in 1998 by the U.S. Green Building Council, the Leadership in Energy and Environmental Design (LEED) program has steadily grown in popularity in the United States and beyond.
In fact, over 7,000 projects in 30 countries are part of the LEED green building certification program.
With the increasing popularity of LEED, we’ve experienced a growing number of clients requesting sustainable design in general and LEED certification in particular. A properly-designed building is inherently sustainable; realistically, there are budgetary limitations that can impact the overall “greening” of a building. Furthermore, we’ve witnessed a growing number of clients request that a project be designed to a certain LEED level, even though they do not plan on actually going through the official certification process.
Over the past year, Nutec Group has worked with two Fortune 500 companies undertaking major construction projects to expand manufacturing facilities. In both cases, these companies had established an initial project goal of LEED Silver Certification. However, the reality of the LEED program is that it is currently difficult, if not economically impossible, to obtain certification for facilities that are major users of process energy.
More than 31 percent of the available LEED points fall under the Energy & Atmosphere category, which has a prerequisite for minimum energy performance that must be met to qualify for any certification level. This creates a huge challenge for a manufacturing facility because the formula is based upon energy reduction compared with total energy consumption within a facility. In a manufacturing environment – in this case automotive production and food processing – the majority of a building’s energy usage relates to process energy, which is essentially a non-variable component in the demonstrated energy savings. While an overriding goal is always to design the most energy efficient system possible, within a client’s budgetary constraints, the ability to demonstrate energy reduction primarily lies within office, storage, and non-process MEP systems, which are typically a small slice of the energy pie.
To mitigate this challenge, the LEED program allows projects to demonstrate energy savings realized in the process energy when compared to energy usage. Unfortunately, in both of the aforementioned projects, this was not able to be achieved, at least not to a level within a given industry that met prerequisite savings.
With these manufacturing clients, we evaluated several options, including onsite renewable energy and purchase of green power. In addition to the significant initial cost of installing a renewable energy system, such as wind, solar, or geothermal, we had to evaluate the number of LEED points that could be earned. Ultimately, we determined that a substantial financial commitment was needed to obtain a minimal number of LEED points. The purchase of green power was possible, but because of the heavy energy usage of the manufacturing process, the small premium paid to purchase green power added up to a very significant ongoing expense.
Another challenge when trying to obtain LEED certification in a manufacturing environment relates to the HVAC and lighting systems. LEED awards points for increasing the volume of outdoor air; however, when dealing with large spaces typically found in production areas, this increase in outdoor air corresponds with a decrease in energy efficiency. LEED also awards points for individual control of the HVAC and lighting systems; again, this is not practical in the large open manufacturing spaces with potentially large employee pools.
[blockquote align="left"]If the U.S. Green Building Council develops a specific LEED rating system for manufacturing, the pathway to formal LEED Certification should become more realistic. [/blockquote] The use of natural lighting – referred to as daylighting – is another way a project can earn LEED points. Unfortunately, there are several criteria that must be met to earn points. These include a minimum of 75 percent of all occupied spaces having daylighting to a minimum allowable footcandle level. An additional point can be earned if 90 percent of the occupied space has a line of sight view to the outdoors with glazing between 30 inches and 90 inches from the floor. While these requirements can be obtained in administrative areas, they are not always practical in the manufacturing spaces and would require a significant amount of roof penetrations (skylights, monitors) to meet the minimum allowable footcandle levels to the spaces far below the roof. With expansive roof areas, many clients are wary of multiple roof openings that can lead to leaks and maintenance issues over time.
Another challenge we encountered related to parking capacity. LEED rewards limiting parking areas and awards points for reducing parking capacity to encourage alternative transportation. Unfortunately, the nature of many manufacturing facilities is one that operates both day and night, with several shift changes over a 24-hour period. This frequently results in the need for increased parking to accommodate two shifts of workers during periods of overlap. Furthermore, we found that the labor pool for both of our manufacturing clients came from a multi-county area, which limited the opportunity to promote public transportation and encourage carpooling. This resulted in the need for parking for two shifts of employees, which exceeded zoning minimums and LEED criteria.
The large parking areas typically required with manufacturing facilities also create a challenge when trying to earn points for minimizing the non-roof heat island effect. Points can be earned if 50 percent of the hardscape is shaded by trees or architectural structures. While this is possible to obtain, it is expensive because of the sheer size of the hardscape, which often include spaces for truck parking and paved areas adjacent to building truck docks. There are some Sustainable Sites points available for maintaining or returning a large portion of land to its natural state; however, corporations may be wary of doing this as they may have plans for future growth and expansion.
The round-the-clock nature of many manufacturing environments also creates a challenge when it comes to reducing light pollution – another area in which LEED points can be earned. Parking lot lighting is typically necessary for security as well as pedestrian and vehicle circulation. Openings in a building’s exterior envelope, like windows and skylights, also emit light pollution. To earn LEED points, the non-emergency lighting levels must be significantly reduced or shielded between 11 p.m. or 5 a.m. Lighting levels in occupied manufacturing spaces cannot be reduced to earn credits, and in many cases the cost of installing window shading is significant and cost-prohibitive.
Wastewater reduction presents another challenge. For instance, it is possible to obtain points for water reduction through low-flow toilets and waterless urinals; however, the cost associated with implementing a graywater system for nonpotable water can be prohibitive. We calculated a payback of 40-50 years for our two recent manufacturing projects. In both cases, the owners simply could not justify the expense, particularly with regard to the intense competition for capital.
Materials and Resources is one LEED category where manufacturing facilities generally do well. Points can be earned from building reuse, incorporation of products with recycled content, use of regional materials, and construction waste management. However, use of rapidly renewable materials, another way to earn points, is difficult to achieve in an industrial environment due to their limited quantities. Limited quantities do however help gain points for the use of certified wood, which typically has a minimal impact on the project budget.
There are myriad challenges associated with obtaining LEED certification in a manufacturing environment; in the case of our two Fortune 500 clients it was impractical because neither facility could meet the energy reduction prerequisite without an excessive investment in renewable energy. However, there are still many sustainable strategies that can be employed to help “green” a manufacturing facility.
The use of highly efficient systems will greatly increase energy performance and makes good financial sense for the owner when viewed from the perspective of life cycle cost reduction. Significant amounts of daylight through windows, skylights, roof monitors, and clerestories can enhance the indoor environment while reducing lighting requirements during the day, even if it is not enough to obtain LEED points. Daylight views through windows in exterior walls are still possible, and can enhance employee production, though again the minimum requirements for LEED points frequently cannot be met. Use of recycled materials and products with low-e content makes a lot of sense, as does specification of regionally-produced materials. In fact, both of our manufacturing projects performed well in this area.
A lot of the strategies outlined in the LEED program are appropriate techniques for enhancing a building’s sustainability; however, in many, if not most cases, the cost associated with obtaining the required minimal levels does not offer payback periods that can be justified to shareholders. However, corporate sustainability may be a strategic or marketing goal, where the added expense of making a facility LEED certifiable may be justified. In these cases it is best pursued when the process system designs can be incorporated into the overall energy savings strategy.
If the U.S. Green Building Council develops a specific LEED rating system for manufacturing, as it has already developed for schools and core & shell projects, the pathway to formal LEED Certification should become more realistic.