The Building Performance Factors and subsequent PCI metric in recent versions of ANSI/ASHRAE/IES Standard 90.1 have caused much confusion and frustration in the industry. This lightning talk will highlight the Continuous Maintenance Proposal that has questioned if the BPFs need to be redone again; or have the process rethought in order to remove inherent biases; or be retired completely in lieu of an alternative more transparent metric.

The Pacific Northwest National Laboratory (PNNL) introduced a collection of 16 commercial building prototypes in early 2000, each designed with a set of assumptions aimed at streamlining building representation. These prototypes continue to serve as foundational tools in various industry standards, such as ANSI/ASHRAE/IES Standard 90.1, facilitating tests and the development of new Building performance factors like the Performance Cost Index (PCI). Despite efforts by Oak Ridge National Laboratory (ORNL) to refine space types for small and medium buildings in their paper 'Updated OpenStudio Small and Medium Office Prototype Models,' these adaptations still offer simplified representations of realistic office designs. Consequently, there is a pressing need for prototype models to accurately reflect real-world building dynamics. This study will contrast the performance of a model building that is more representative of a real building with that of both the PNNL medium office prototype and the updated ORNL model. Each building will be tested in multiple weather locations, and they will share identical floor area and building shell characteristics but will differ in space type, and zoning.

The building industry's focus has evolved from a longstanding emphasis on reducing energy consumption to a recent paradigm shift towards mitigating Greenhouse Gas (GHG) emissions. In line with the White House's newly defined national definition for net zero, emphasis has been placed not only on energy efficiency but also on minimizing on-site emissions and harnessing clean energy for building operations. USGBC LEED v5 draft has introduced innovative credits specifically targeting Decarbonization Assessment, and various ASHRAE Standards and Building Performance Standards (BPS) are incorporating essential decarbonization elements in their requirements.

While the objective and path of achieving net zero for new constructions has been clear, albeit challenging, existing buildings present a more complex scenario. The initial step in decarbonizing any existing building involves a comprehensive assessment of the existing systems, to identify the potential for energy efficiency, electrification, operational improvements, and renewables. Benchmarking the existing building performance and quantifying existing Scope 1 and Scope 2 emissions are important to understand building performance. This is followed by defining a comprehensive plan for emission reduction with a timeline for the implementation of measures. This process is intricate, involving multiple Key Performance Indicators (KPIs) and assessment considerations.

This presentation introduces a capability being added to Audit Template developed by PNNL, designed to facilitate Decarbonization Assessments. Multiple jurisdictions require the use of Audit Template to demonstrate compliance with the alternative compliance pathways in their BPS. With the inclusion of decarbonization assessment capability, Audit Template would facilitate the development of decarbonization plans by providing a standard interface for data collection and reporting. It will further calculate existing scope 1 and scope 2 emissions, and track that against the BPS target. By standardizing the way building systems, refrigerant leakage, electrical vehicles, on-site and off-site renewables and electrical infrastructure are reported, it would allow the authority having jurisdiction (AHJ) gain insights into the feasibility of decarbonization for the building stock and use this data for decision making. In addition to guiding an AHJ, it would provide a building owner insight into their building’s performance and identify their trajectory to net zero emissions. Through the Scenario Analysis Tool, Audit Template would encourage assessors to develop strategic decarbonization plans which consider load reduction and energy efficiency before electrification.

This presentation aims to provide insights into the challenges associated with decarbonizing existing buildings and how Audit Template is standardizing this complex process to provide an interface for assessors, building owners to report building data and for AHJs to analyze the building stock. This presentation will also discuss some of the key insights a jurisdiction could glean about their building stock and how that can facilitate policy development to support a move towards net zero emissions.

In the dynamic landscape of urban development, the intersection of sustainability, regulatory compliance, and grid resilience takes center stage. As a sustainability reviewer at the Boston Planning and Development Agency, assessing large-scale developments exceeding 50,000 sqft, I review building performance and advocate improvements for compliance. My Lightning Talk at SimBuild 2024 will showcase a data visualization exercise that illuminates the intricacies of this process, particularly focusing on the city's onsite renewable generation capacity through rooftop PV and a simultaneous increase in renewable demands of upcoming developments in Boston.

Drawing from a wealth of data embedded in Article 37 Green Building filings and Climate Resilience checklists submitted by the collaborative proponent team (developers, architects, sustainability consultants, energy modelers, and MEP consultants), this presentation will feature insightful visualizations of a data subset from the past year. Some metrics the agency tracks include LEED certifiable scores, envelope data, building emissions intensity, onsite and offsite renewable energy capacities, load demands, and more. This is a recent initiative with much work still remaining, so the content is best suited for a short introductory presentation.

I will guide the audience through observed trends in onsite renewable generation and renewable demands across different building use types, fostering an engaging dialogue on the critical role of climate resilience data and forecasting in improving a city's grid reliability. Of special interest is how these data points can serve as a vital tool for utilities, enabling them to proactively manage and plan for area/ neighborhood substation growth and optimize peak loads through well-designed Demand Response programs.

This Lightning Talk will highlight achievements and candidly address the challenges of handling and interpreting large datasets. Moreover, it will explore opportunities for collaborative enhancements in the regulatory process. Aimed at professionals directly involved in these processes while on the other side of the table, this presentation holds relevance and invites an intriguing discussion on how leveraging climate resilience data can enhance urban grid reliability and inform progressive regulatory frameworks.

The presentation will discuss the benchmarking standards in place in the City & County of Denver and the State of Colorado. We will discuss the importance of the progression of predictive energy modeling and how it differs from the comparative modeling used by IECC section C407 and ASHRAE 90.1 Appendix G. We will review an analysis of energy model results compared to actual building performance (benchmarked results) for multifamily buildings, offices, and one or 2 other building types. We will share improvements that we have made to our energy modeling protocols to yield more accurate EUI predictions to assist new construction projects in developing an energy-efficient building that will comply with the existing building benchmarking and performance standards straight out of the ground.

This presentation provides a unique perspective on the energy efficiency journey of an under-construction market rate multifamily project undergoing National Green Building Standard (NGBS) verification. By sharing valuable insights gained during the construction phase, this exploration aims to elucidate the inherent benefits of integrating NGBS verification for heightened energy performance.

The ongoing project serves as a live case study, offering real-time observations on the integration of NGBS standards into the construction process. Key components, including energy-efficient design, insulation, and HVAC systems, are examined for their impact on energy performance. This presentation demonstrates how adherence to NGBS criteria inherently contributes to elevated energy efficiency levels, showcasing practical learnings that extend beyond theoretical standards.

Through the lens of this ongoing project, we delve into the challenges, successes, and transformative effects on energy consumption. The presentation highlights the dynamic relationship between construction practices guided by NGBS principles and the subsequent enhancement of energy performance.

As construction unfolds, the presentation presents tangible examples of how NGBS verification acts as a driving force for developers and builders to achieve superior energy efficiency outcomes. Beyond compliance, the narrative emphasizes the project's potential to serve as a benchmark for others, providing actionable insights into the direct correlation between NGBS verification and improved energy performance.

This presentation invites industry professionals, developers, and researchers to glean from the project's experiences, demonstrating that even in the midst of construction, the principles of NGBS verification actively contribute to shaping a more energy-efficient and sustainable future for market rate multifamily developments.

In conclusion, the ongoing construction project serves as a living laboratory, unraveling the inherent benefits of NGBS verification in the context of energy efficiency. This offers a dynamic exploration of practical learnings, positioning NGBS verification as an integral component in the quest for sustainable, energy-conscious multifamily projects.

EnergyPlus is the Department of Energy’s (DOE) flagship simulation engine for building energy modeling (BEM). Conceived in 1996, development and use of EnergyPlus has historically been driven by commercial building interests. Despite having state of the art, physics-based models suitable for any building type, EnergyPlus’s potential for residential buildings has been largely untapped due to its steep learning curve, gaps in a few critical areas, and slow runtime speed. To address these issues, NREL embarked on developing an EnergyPlus-based product specifically designed for third-party software developers that is significantly easier to adopt, capable of modeling a wide range of residential technologies, and fast. The product is a standalone, open-source modeling workflow that facilitates residential use of EnergyPlus. The workflow leverages existing products – HPXML for a residential data transfer standard and OpenStudio for its software development kit – and has incorporated continuous improvements, rigorous testing, careful selection of algorithms with respect to accuracy/speed tradeoffs, and modeling enhancements to EnergyPlus itself. Today this HPXML/OpenStudio workflow underpins many prominent DOE and industry software tools and analysis products, models hundreds of thousands of homes each year, and serves as a benchmark against which other software tools are compared for accuracy and consistency. In this presentation, we explore the residential BEM landscape, examine the HPXML/OpenStudio workflow and its software architecture, and highlight benefits accrued to DOE and industry.

This work, which is funded by the U.S. Department of Energy via Argonne National Laboratory, seeks to include test cases in ASHRAE Standard 140, Method of Test for Evaluating Building Performance Simulation Software, that compare software results with empirical data. This presentation updates a presentation at BPAC 2023 and describes:

• A test facility specifically designed for empirical validation of building thermal fabric models.

• Artificial-climate (test cell fully guarded from weather) steady-state characterization test cases that are a pre-requisite for developing more dynamic test cases

• Steady-state heating energy measurements and their uncertainty, which provide a target range for software results

• Imputation of selected thermal conductivities based on empirical determination of as-built thermal boundary surface UA-values and interior and exterior surface heat transfer coefficients. Such imputations provide model inputs that accurately characterize the test facility.

• Simulation results from seven different software, six of which were run by international industry software developers, indicating conclusions regarding the ability to:

o Model steady-state conduction (we expect this, but difficult to design and implement an experiment to prove it and then apply that as a foundation for more complicated cases)

o Use the test suite diagnostic output to isolate input errors

o Quantify the importance of imputing selected thermal conductivities based on measured surface UA-values

o Validate and compare surface heat transfer algorithms appropriate to the test cases, and especially the importance of comparing interior surface convection algorithms driven by natural convection (buoyancy) airflow versus by mechanically driven airflow.

And also describes:

• Improvements to the test specification (about 100 revisions) from running simulation trials (that generated about 20 comments not including typos) – very important reason for doing simulation trials

• Improvements to software so far, as a result of running the test cases

• Next steps to move from the foundational work to developing more dynamic test cases.

Co-authors on the project:

Presenter: Joel Neymark, J. Neymark & Associates, neymarkj@msn.com

Co-Author: Ji-Hyun (Jeannie) Kim, Argonne National Laboratory, Jeannie.kim@anl.gov

Co-Author: Ralph T. Muehleisen, Argonne National Laboratory, rmuehleisen@anl.gov

Co-Author: Timothy P. McDowell, Thermal Energy System Specialists, LLC mcdowell@tess-inc.com