How Much Green is Too Green?

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By Russ Sullivan, P.E. LEED A.P.

In today’s design and construction industry it is imperative that the design and construction of buildings address sustainability. To include some aspect of LEED (Leadership in Energy and Environmental Design) is often the goal.  Sustainable design is one of the hottest subjects in the design and construction industry today.  Why are owners, architects, engineers, designers, and contractors interested in sustainable design?  A few good reasons include:

  • Reduced pollution emitted into the environment
  • Conservation of natural resources for our children’s children
  • Protection of natural habitats
  • Development of eco-friendly building practices

Sustainable design and construction is loosely defined as:  creating buildings and communities that conserve natural resources.  This includes using renewable resources as much as possible to preserve non-renewable resources for future generations.  A far reaching definition of sustainable architecture includes the concept of zero emission buildings or buildings that function without polluting.

LEED design is a national certification system developed by the US Green Building Council, a non-profit company that encourages the design and construction of buildings to use fewer resources, reduce energy consumption, and provide a healthy work environment.  The LEED Certification System is voluntary, and addresses most building types including new construction, major renovation, existing buildings, commercial interiors, schools and homes.  LEED certification is intended to reduce operating costs, increase occupant comfort, and enhance building marketability.  For the reasons listed above, every project, every design, every building should include the most sustainable design and the highest LEED certification available.  Right?  Well . . . Maybe.

Have a discussion about sustainability with a salty old building engineer or plant maintenance supervisor. The conversation typically goes like this:  We would like you to invest additional money into this new energy saving device.  The device is going to reduce your utility bills.  The engineer or plant supervisor asks:

  • What is my return on my investment?
  • What is the life cycle cost of the new system?
  • Will I at least save enough energy dollars during the life of the equipment to pay for the equipment?

All of these important questions can be answered with the help of a Life Cycle Cost Analysis.  Would a building owner invest $100,000 now in order to create a return of $4,000 a year for the next 20 years?  Of course not.  Why would a building owner invest additional dollars for a piece of energy-saving equipment when the energy-savings over the life of the equipment will not pay for itself?

The only way to be sure that a piece of equipment, device, or system is a good investment is to complete a life cycle cost analysis.  With the use of computers and software available today, the cost to do a life cycle cost analysis is insignificant with respect to the project cost.  There are several programs on the market that can create a bin or block method building model in less than an hour and provide realistic results.  Of course there are also programs available that may require 40 hours to construct a computer model, run an hour by hour analysis, and produce incredibly accurate results.  In either case, the life cycle cost analysis incorporates:

  • The additional installation cost and first time cost of the system being evaluated
  • The potential energy savings due to the increased efficiencies of different types of systems
  • Maintenance costs
  • Fuel costs
  • The revenue penalties or rewards stemming from tax credits

The result will be the total cost to operate the system for the life of the equipment or the life of the study.  Multiple system types can be modeled and a life cycle cost analysis and return on investment completed for each system.  As with any energy analysis, the accuracy of the analysis is directly proportioned to the accuracy of the program inputs.

Please understand that I am not saying not to do sustainable design or obtain LEED certification for buildings.  We have always strived for energy efficiency and responsible design; this is at the core of our training. The current drive “to be green” may lead to decisions that do not support an economic rationale. LEED is a system that helps to provide a framework for sustainable buildings but needs to be thoroughly analyzed to make intelligent decisions.  With a balance of appropriate energy savings (to achieve LEED points) with the proper equipment selection (using a life cycle cost analysis) an economical system design and sustainable construction project will be achieved.  If there are other benefits to increasing the investment of energy saving equipment then life cycle cost analysis may not be as relevant.

So how much green is too much green? . . . A life cycle cost analysis can help frame the discussion to reach and informed decision.

Russ Sullivan is a professional engineer and LEED Certified Senior Associate at Stantec Architecture and Engineering LLC. Russ works out of the Stantec Butler, Pennsylvania Office and can be reached at russ.sullivan@stantec.com.