Last year we made the offer to address readers’ questions and comments regarding sustainability. Over the past few months the questions have not been abundant, but the quality is quite sophisticated. Following is an inquiry that includes several questions on related topics, each of which are addressed accordingly:
- “Does anyone go back and see if building owners are maintaining sustainable practices years later?
- What about buildings that are sold? Who becomes its steward for those areas/credits that someone worked so hard to achieve.
- What if neighborhoods change down the road, etc.?”
Does anyone go back and see if building owners are maintaining sustainable practices years later?
In the early days of LEED, once a building was certified, it was certified. While the U.S. Green Building Council
(USGBC) encouraged continual energy measurement, there was no mechanism or requirement for a building owner to measure, record or maintain their buildings in accordance to the LEED requirements. These first-generation buildings followed the guidance provided by the USGBC and LEED reference manual for design and construction.
A project team needed to document the credits and prerequisites to be certified. During this time, the LEED rating system had one point available to building owners who wanted to measure and verify building performance. While this credit was worth one point, the benefits an owner could achieve through a program of Measurement and Verification (M&V) could bring value and operational cost savings. So, why was it then that this credit point for M&V was the least likely to be sought or achieved by a delivery team? Unfortunately, in my opinion, the decision to not pursue the M&V credit was motivated by design teams that did not want to be accountable for their design.
Before my inbox becomes full of complaints, let me explain. Many engineers feel that if they say their design will achieve a certain level of efficiency, and it has been proven by calculation or simulation, they need not continue to prove the building performance. Beyond the design, many designers do not want the building performance to be tracked because more times than not, the building does not perform the same way as was predicated through the energy model simulation. Yes, I said it; rarely does a building perform identically to the energy simulation model created for the building during the design phase. Why?
The reason a building rarely, if ever, performs identically to the simulation model is because building performance is directly dependent on how the occupants use the facility. A design team can design an incredibly efficient building, but if it is not constructed the way it was designed, it will not be as efficient as first designed. A building can be designed to be efficient and constructed to the exact specifications, but if it is not operated the way it was designed and constructed, the predicted efficiencies will never be realized. Is there a flaw in the system or in the model used for LEED certification?
No, the system nor the energy model software is the problem. The problem arises when the designers and the energy modeler make assumptions about the way the building will be used after construction.
A real-life example of this gap between design and reality is with my first LEED-certified building. This building was designed to be 50 percent more efficient when compared to the baseline building. However, when efficiency was measured six months after completion of construction, the team found that the building was consuming 50 percent more energy than what was predicated. Needless to say, the building owner was not happy and demanded a reason why the building was using more power than predicted.
The corresponding investigation revealed that the problem was not with the design or construction; it had to do with how the facility was operated. When constructing the energy model a set occupancy schedule of 7 a.m. to 6 p.m. five days a week, plus one half-day every Saturday, was used. In actuality, the building was operating from 4:30 a.m. to 11 p.m. five days a week, with eight hours each Saturday. The increase in operating hours was approximately 50 percent more hours per week.
The team recalibrated the model to reflect operating conditions and measured the energy use over the next four months. At the end of this period, the owner observed that the energy use predicted with the recalibrated model and the actual energy use were close to the same. As time went on this particular building owner used the recalibrated model to measure and monitor the overall building energy performance, looking for ways to drive down energy use.
No one checked on building performance after the project was completed. As the LEED rating system evolved, measurement and verification became more important. LEEDv3 imposed Minimum Program Requirements, one of which requires the building owner to furnish information regarding the energy and water use to the USGBC for a period of no less than five years. Another requires an owner to put forth best efforts to make the building’s sustainable concerns part of the sales contract. With LEEDv4, measurement and verification is not a prerequisite, but the metering and the capability to measure building performance is.
To directly answer the question, the answer is no. No one comes to your building to review your energy and water use. The USGBC does however require a building owner to measure, record and furnish energy and water use data for their own research.
What happens to the LEED certification if the building is sold? Who becomes its steward for those areas/credits that someone worked so hard to achieve?
The new building owner if they chose to do so.
What if neighborhoods change down the road?
LEED for neighborhood development is a unique rating system dealing with the rhythm and patterns of a neighborhood, which is a topic for another column.
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Thomas Taylor, a 30-year veteran of the construction industry and noted expert on sustainability, is the general manager of St. Louis-based Vertegy. To learn more about Vertegy, visit www.vertegyconsultants.com.