With the regular introduction of more aggressive energy codes, efficiency program administrators are becoming interested in understanding the energy impacts of different levels of compliance on building energy performance. As studies have demonstrated, standard practice in new construction tends to be somewhat lower than mandatory energy code compliance. Thus, programs that promote higher performance buildings can produce the joint benefit of energy savings due to (1) improved levels of compliance and (2) premium efficiency new construction features. The challenge, however, is identifying cost-effective techniques for estimating the energy impacts.

Two commercial construction baseline and energy code compliance studies that included detailed field evaluations of over 100 commercial buildings in Massachusetts and Rhode Island have uncovered many opportunities in new construction projects to improve code compliance and energy efficiency, with savings achievable in all technology areas. All energy code categories (administrative, building envelope, HVAC, lighting, and controls) were addressed in the studies, and compliance ratings or scores were developed through a modified DOE/PNNL methodology.

The next phase will use a combination of cost-effective modeling techniques to model energy impacts. Engineering methodologies that are under consideration include simulation modeling, custom spreadsheet analysis, and a combined, integrated approach. Currently, we are conducting meetings with energy modeling experts to assess the merits of various techniques, striving to arrive at conclusions on the most suitable mix of approaches, including:

• Simulation modeling and analysis – Simulation analyses would be performed with a DOE-2 based model like eQUEST. While the authors do understand the merits and analytical power of these tools, particularly for proto-typical buildings, we also consider the challenges and costs of such analyses for real, complex facilities in which construction details may be poorly known. Thus, our intentions are to use simulation analyses to model code deficiencies associated with major envelope systems, central controls, and other whole building challenges.
• Custom spreadsheet analysis – For many stand-alone code requirements, including those for lighting, HVAC, local controls, and smaller envelope issues, custom-developed spreadsheet tools will be suitable. These are anticipated to be more cost-effective, straightforward in use, and transparent in quality control assessment.
• Integrated approach – As outlined above, there are merits to both simulation and custom spreadsheet modeling analyses. Our end objective will be to combine the two approaches, likely using the simulation for determining major building envelope, whole building control, and interactive impacts, and using spreadsheet analyses for lighting, unitary HVAC, and individual control measures.

The final results of the study will demonstrate a cost-effective and enhanced analysis protocol, providing energy impacts for a project from standard practice to compliance and then to premium efficiency. Such methodologies must be consistent with the need to assess complex new construction projects, while developing evaluation-ready energy results.

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