It’s time to acknowledge that LEED standards, as they exist today, increase cost without increasing value. Without committing to fundamental reform of the building development process, Green points from LEED have little if any effect on the overall project. LEED gives points producing the symptoms of a good development process. Most designers, and most owners, opt to produce the symptoms, and leave the flawed processes intact.
The Leadership in Energy and Environmental Design (LEED) Green Building Rating System is the accepted benchmark for the design, construction, and operation of high performance green buildings. LEED promotes a whole-building approach to sustainability by recognizing performance in five key areas of human and environmental health: sustainable site development, water savings, energy efficiency, materials selection, and indoor environmental quality. A project is a viable candidate for LEED certification if it can meet all prerequisites and achieve the minimum number of points to earn the Certified level of LEED project certification. Projects are awarded Certified, Silver, Gold, or Platinum certification.
Unfortunately, LEED can reward those with existing bad processes more than it can acknowledge existing good ones. If you made bad decisions in the past, you get extra points for not making them again. It is too easy to greenwash a project by adding an energy modeling component that has no intrinsic tie to the construction documents. The routinely incomplete documentation of building systems means that the actual wiring and operations is dependent upon the creativity of the subcontractor rather than the Green design. With incomplete system documents, commissioning is a demanding but ultimately futile function. Innovations in system design are lost in normal maintenance and operations due to the inaccessibility or incompleteness of the documents handed over.
To achieve the results LEED aims for requires not just gaming symptoms, but rather an actual commitment to good processes, for the planning, design, construction, and operation of capital assets. The foundation for these good processes must be a non-transient base of information that is accessible throughout the entire building life-cycle. All process audit functions, whether energy modeling, code compliance checking, or even commissioning must be based directly on that information base. If we used such a process, most of the LEED points would fall automatically from the process, with little extra effort necessary.
When we score LEED points without examining the underlying process, we are summing nonsense. Here are some specifics:
- At UNC, buildable lots are identified and cleared five to ten years before construction starts. Every clear lot is, as on most campuses, used as a parking lot. Today, we get green points because under LEED, siting buildings on brown fields, such as parking lots, is a best practice.
- We specify, for reasons that are primarily historical and regulatory, CAD-based designs. To get green points, we require that the designer acquire an energy model. That model has no intrinsic link to the CAD design, and there is no way to determine if value engineering removes the features modeled.
- Building systems are drafted as crude schematics, with no provable links to actual wiring and control tags. This creates building monitoring systems that cannot be linked back to the design, nor to the energy model. This makes commissioning more arduous and less effective.
- Practitioners in retro-commissioning, that is the process of re-visiting a building possibly years after initial construction and examining system operations are unanimous; nothing would be worse that returning the building to its initial design state. Even in new buildings with high LEED ratings, the control systems were only partially designed at best.
Without a design process that actually includes the mechanical systems and their controls, there is no underlying operational model for the building. Without an underlying model, ongoing system maintenance is based upon guesses. Without live performance metrics, including instant access to energy metering, linked to that model, than building system operations are based upon experience and guesswork. When the system is green and non-traditional, you can eliminate experience, leaving only guesswork. to operate the building, and to tell if the building is being tuned into or falling out of control.
The solution to these problems is an integrated data model for the building whose life extends as long as the life of the building. The data model starts with the capture of the design intents. Building designs should be models, not drawings, and should be standards-based. The energy model would then run directly off the building model and could be compared to the design goals. Changes to the design, especially during value engineering when many innovative features are eliminated, could be automatically reflected in updated energy models.
The electronic building model should be available electronically to each bidder and used throughout the construction process. The increased accuracy of the bid package and reduction in change orders during construction would reduce costs and result in as-built models that match the initial design. These accurate designs, delivered to the owner, would include full identification of the internal systems, their components, and their performance expectations.
With delivery of the as-built models, using system identifications consistent with the initial design documents, building commissioning becomes validation of performance to the design. In the case of energy systems, commissioning becomes validation to and alignment with the energy model. This, at last, becomes a significant improvement over the traditional standard, described, only half in jest, as “no sparks”.
Under this business model, LEED credit would become relevant. Each LEED point is no longer a game-able item separate from the actual business process, but an intrinsic metric of the quality of the process. Facts necessary to support innovative systems would be available to maintenance and operations throughout the life of the building. Those would be green points worth earning.
Note: I know of and am watching eagerly the development of ASHRAE standard G189P. I think the observations here are aligned with its intent, It will offer some improved structure that will lead to measurable sustainable performance.
