Building Energy Efficiency Metrics: From Title 24 to EUI
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The document discusses the importance of selecting appropriate energy efficiency metrics for building design, focusing on the implications of different metrics like Title 24 and LEED. It emphasizes the risks of using obsolete or overly complex metrics and advocates for a streamlined approach that includes energy use intensity (EUI) alongside other metrics for better decision-making. Recommendations are provided for improving metrics to enhance design outcomes and compliance with sustainability goals.
Building Energy Efficiency Metrics: From Title 24 to EUI
- 1. Building Energy Efficiency Metrics Helping clients pick better metrics Neil Bulger, PE Integral Group Alex Krickx, Integral Group
- 2. Example Large Project GOALS: LEED, Title 24 2013, Energy Efficiency, and an on-going owners project requirements (OPR) of additional goals MEP DESIGN: Radiant-cooling w/ VAV, waterside economizer and heat recovery In a rush at the end of the project, the owner asks design team to make a plan for measurement and verification using the T24 permit compliance model, which does not represent the new technologies. Concept SD DD/CD Permits Occupancy M&V EUI / LEED Title 24? EUI / ASHRAE 90.1?Modeler Client
- 3. Example Small Project • Multiple building school project • Scope and fee for code-compliant modeling • Originally, no plan to model extensively during schematic phase • During design development, client now asks to explore envelope assemblies • We only had EnergyPro T-24 model • Client asked for T-24 results to inform envelope decisions • Mechanical design has no cooling.
- 4. Rough Results (not issued) • Results show almost no change in any measure • T24 model includes cooling, though design has no cooling • Most savings are heating (gas) and are not important to T-24 • Model not intended for performance modeling • Confusing results that we ultimately did not show to client
- 5. Topics to discuss • All metrics are not created equal • The benefits of choosing metrics • How do we choose better metrics? (by project phase and deliverable) • How do we (as a community of professionals) implement better metrics
- 6. Energy Metrics for Buildings T24 California Energy Code (Beyond T24 Most California Universities) LEED pts USGBC Green Certification Energy Star Building Portfolios ASHRAE 90.1 Federal / State Energy Codes Energy Cost Long Term Owner, Tenant Predicted EUI Energy Use Intensity, per gsf Measured EUI After Construction
- 7. Picking an Energy Metric Most decisions are not actually made! Decisions tend to fall to whatever the default condition is. Our experience has found most clients will pick T24 in California.
- 8. Making a choice takes effort, whereas sticking with the default is effortless. Another reason is when decisions have unclear costs and benefits that are difficult to evaluate, defaults can imply the “recommended” option, thus saving people the time of thinking through the choice themselves. Behavioral Economics
- 9. Benefits of Better Metrics • Capturing New Technologies • Making Active Design Decisions • Useful in Multiple Project Phases • Useful for Larger Portfolio Planning • Streamlined Process • Same language as other Prof Orgs (like AIA)
- 11. Different types of EUI
- 12. Time/fee for energy modeling from AIA
- 13. How can we compare metrics Metric Project Timelines Project Sustainability Goals Mitigating Risk Maximizing Opportunity
- 14. Project Timing & Phase A B C Concept SD DD/CD Permits Occupancy EUI LEED pts T-24
- 15. Project Sustainability Goals LEED pts Code Compliance (“20% better Title 24”) Arch 2030 Savings by Design Net Zero Design Performance
- 16. Multiple Goals - Multiple Metrics LEED Net Zero Code Compliance EUI Metric T24 LEED pts Energy Star ASHRAE 90.1 Energy Cost Predicted EUI Measured EUI Arch 2030 T24 Goals Code Compliance LEED pts Design Performance Savings by Design Net Zero Arch 2030 LEED pts
- 17. Risk of a Metric • Metric becomes obsolete in project lifetime • Metric does not provide enough granularity • Complexity of baseline • Metric does not address goal (ex: LEED req'd cooling negatively impact nat vent project) • Metric does not address current technology • Metric skews results in favor/against project
- 18. Opportunity of a Metric • Code Compliance • Capturing New Technologies • Green Certification • Useful in making design decisions • Ability to hold metric through multiple phases (longevity) • Streamlined process • Same language as other prof. Orgs (like AIA)
- 19. Metric 1: Title 24 (California Energy) Code Compliance Capturing New Technologies Green Certification Making Design Decisions Useful in Multiple Project Phases Streamlined Process Same language as other Prof Orgs Opportunities Risks Metric Becomes Obsolete Doesn't Provide Enough Granularity Complexity of Baseline Doesn't Address Goal Doesn't Address Current Tech Skews Results (better or worse) Dashed Outline = Sometimes True, depends on the project Solid Outline = Always True
- 20. Title 24 Metric 1: Title 24 (California Energy) Code Compliance Capturing New Technologies Green Certification Making Design Decisions Useful in Multiple Project Phases Streamlined Process Same language as other Prof Orgs Opportunities Risks Metric Becomes Obsolete Doesn't Provide Enough Granularity Complexity of Baseline Doesn't Address Goal Doesn't Address Current Tech Skews Results (better or worse)
- 21. LEED Risks Metric Becomes Obsolete Doesn't Provide Enough Granularity Complexity of Baseline Doesn't Address Goal Doesn't Address Current Tech Skews Results (better or worse) Code Compliance Capturing New Technologies Green Certification Making Design Decisions Useful in Multiple Project Phases Streamlined Process Same language as other Prof Orgs Opportunities
- 22. EUI Risks Metric Becomes Obsolete Doesn't Provide Enough Granularity Complexity of Baseline Doesn't Address Goal Doesn't Address Current Tech Skews Results (better or worse) Code Compliance Capturing New Technologies Green Certification Making Design Decisions Useful in Multiple Project Phases Streamlined Process Same language as other Prof Orgs Opportunities
- 23. Risk Summary Metric Becomes Obsolete Doesn't Provide Enough Granularity Complexity of Baseline Doesn't Address Goal Doesn't Address Current Tech Skews Results (better or worse) T24 LEED pts Energy Star ASHRAE 90.1 Energy Cost Predicted EUI Measured EUI
- 24. Opportunity Summary Code Compliance Capturing New Technologies Green Certification Making Design Decisions Useful in Multiple Project Phases Streamlined Process Same language as other Prof Orgs T24 LEED pts Energy Star ASHRAE 90.1 Energy Cost Predicted EUI Measured EUI
- 25. Opportunity Summary Sad Faces Happy Faces T24 8 2 LEED pts 5 5 Energy Star 2 2 ASHRAE 90.1 2 4 Energy Cost 1 4 Predicted EUI 1 10 Measured EUI 1 5
- 26. How do we implement better metrics? Where do you see opportunities to do this? How do we choose better metrics? (by project phase and deliverable) How do we (as a community) implement better metrics?
- 27. Recommendations • Use Energy Use Intensity with any other metric, such as LEED or T24 for a reference • Include it in reports even if not the primary metric • Teach a general knowledge of performance targets being more concrete and easier to understand • Limit the client complexity and focus on what is needed on specific jobs to stay compliant
- 28. NREL ESIF DataCenter PUE Heat Recovery EUE 30% Above ASHRAE 90.1, 2007 Office Energy Density LEED v2.2 Gold NREL ESIF
- 29. J Craig Venter Institute DESIGN Chilled beams with water-source heat pumps, nat vent. GOALS Title 24 LEED Living Building Labs 21 Utility Incentive Net Zero
- 30. Nueva High School DESIGN Radiant heating, natural ventilation GOALS LEED Architecture 2030 Code Compliance
Editor's Notes
- #5: (show graph) (Add that there was DX baseline cooling for half the spaces, skewing the results) Results show almost no change in any measure which are mostly due to savings in heating (gas) and on a Title 24 scale does not really register. Even though many of these improvements will increase the comfort and performance of the building, the model built was created for code-submission and the metric was designed for pass/fail results. This resulted in a confusing set of answers and ultimately we did not present these to the client. The opportunity to quantify the value of these ideas needs support and fee but also needs a better metric to tell a straight-forward story. Opportunity is to give feedback in a rational way instead of wasting time calculating and explaining Title 24.
- #7: Roughly the models