Evaluation of Building Energy Performance Rating Methods ASHRAE TRP-1286 Initial Results Jason Glazer, P.E. GARD Analytics January 2006

2 Project Overview Today’s presentation –Overview of many rating methods –In depth evaluation of five methods Work in progress –Gathered data for 29 test buildings –Test five methods with building data –Recommendations

3 Overview of Many Methods Formal literature search Internet search –building benchmark –building energy benchmark –building energy rating –building energy metric –Building Energy Measure OR Rank OR Gauge OR Grade –Building Energy Criteria OR Classification OR Merit –Building Energy Valuation OR Mark OR Yardstick –Building Energy Target OR Score

4 Overview Results 88 protocols initially uncovered –47 commercial (focus) –31 residential Categorization applied –Use of, or reference to, ASHRAE products –Range of approach –Range of applicable building types –Number of users (subjective)

5 ASHRAE Referenced Standard – Methods of Testing Automatic Ice Makers Standard – Gravimetric and Dust-Spot Procedures for Testing Air-Cleaning Devices Used in General Ventilation for Removing Particulate Matter Standard – Method of Testing General Ventilation Air-Cleaning Devices for Removal Efficiency by Particle Size Standard – Thermal Environmental Conditions for Human Occupancy Standard – Ventilation for Acceptable Indoor Air Quality Standard – Energy Standard for Buildings Except Low-Rise Residential Buildings Standard – Method of Testing Closed Refrigerators Standard – Measuring Air Change Effectiveness Guideline – The HVAC Commissioning Process (G-1) Guideline – Preparation of Operating and Maintenance Documentation for Building Systems (G-4) ASHRAE Handbook – Fundamentals (HOF)

6 Use of ASHRAE Documents

7 Approaches Used Points with prerequisites and reference building simulation Comparison with building simulations Placement within statistical distribution shown graphically or by score Direct comparison of multiple buildings to each other

8 Range of Buildings One specific building type (laboratories) All building types using national public database of buildings Subset of building types using specific databases or statistical model for each building type Common: education, healthcare, hotel, office, retail Broad categories or several subcategories

9 In-depth Evaluation Selected by –Level of adoption –Approach used –Customer focus LEED-NC/LEED-EB – USGBC EnergyStar for Buildings – US EPA BREEAM – UK BRE ARCH/CALARCH - LBNL EnergyPrism Benchmark – Commercial

10 Comparisons Scope of application Empirical basis Input requirements Output and transparency Part of certification process Effort and expense Influences design or retrofit

11 Scope of Application – Building Type Any building –LEED-NC –Arch/Cal-Arch –EnergyPrism Subset of Buildings –LEED-EB –BREEAM –ENERGY STAR Label for Buildings

12 Scope of Application - Geography U.S. –LEED, ENERGY STAR, EnergyPrism, Arch California –Cal-Arch Global –BREEAM

13 Scope of Application – Building Size Some have specific building size range Certification costs discourage small buildings

14 Empirical Basis - Source CBECS – US DOE/EIA –Arch, ENERGY STAR, Energy Prism, LEED-EB California proprietary database –Cal-Arch Private databases –ENERGY STAR (Hospitals, Hotels) No empirical basis –LEED-NC - simulations with 90.1 baseline –BREEAM – ECON 19 comparison

15 Input Requirements Building area and annual energy usage –Arch and Cal-Arch Area by space type, monthly energy usage –ENERGY STAR Label for Buildings Building area, annual energy use, end-use –EnergyPrism Many inputs for each point sought –BREEAM, LEED

16 Output and Transparency – LEED and BREEAM Several specific grade levels provide simple recognition by others –BREEAM: Pass, Good, Very Good, Excellent –LEED: Certified, Silver, Gold, Platinum Points allow cafeteria style selection of measures Lower resolution - not appropriate for multi- building comparisons More than energy: environmental

17 Output and Transparency – ENERGY STAR Number between 0 to 100 with a specific threshold Documentation aimed at analyst Threshold of 75 provides user understanding if improvement is warranted

18 Cal-Arch Output Example Interpretation needed. No threshold.

19 EnergyPrism Output Example Like appliance energy label No threshold Unknown distribution

20 Part of Certification Process ENERGY STAR, BREEAM, LEED –Recognition to building –Third party gives legitimacy –Widely recognized –Adequate lighting, ventilation, comfort –Utility or government incentives –Leveraged by other organizations

21 Effort and Expense No cost – an hour to self-assess –ENERGY STAR, EnergyPrism, Arch/Cal- Arch –2623 ENERGY STAR certified (Jan 2006) With cost – multi-month process –BREEAM, LEED –359 LEED certified (Nov 2005)

22 Influences Design or Retrofit Point systems for design –LEED-NC and BREEAM –Directly influence design –Incorporate with the design process Consumption based protocols –ENERGY STAR, EnergyPrism, Arch/Cal-Arch –Indirect influence on design –May spur energy oriented retrofits –Do not indicate why building performing poorly –Added risk trying to meet threshold

23 Next Steps Data from actual buildings –Office, K-12 schools, hospital, lodging Test methods –Include test cases for major inputs Prepare recommendations for future rating methods

24 Questions