You are here

Building Energy Asset Score Frequently Asked Questions

This page features answers to the most frequently asked questions about the Building Energy Asset Score. Choose from the list of questions below to learn more:

Program Overview

What is the Building Energy Asset Score? The Building Energy Asset Score is a national standardized tool for assessing the physical and structural energy efficiency of commercial and multifamily residential buildings. It is a web-based tool and 100 percent free to use. The Asset Score generates an Asset Score Report that enables users to compare the physical energy efficiency of buildings, communicate building efficiency to the marketplace, and identify opportunities to invest in energy efficiency upgrades. It was developed by the U.S. Department of Energy and the Pacific Northwest National Laboratory.
What are DOE's objectives in creating the Asset Score? DOE's objectives in developing the Asset Score are to expand nationwide awareness of opportunities to invest in building energy upgrades, and to recognize investments that resulted in energy efficiency improvement. The Asset Score is not intended as a replacement for building energy usage benchmarking or building energy audits conducted by engineers.
What does it mean to assess the “physical and structural” energy efficiency of a building? The Asset Score provides a targeted energy efficiency evaluation of a building’s envelope (its roof, walls and windows) and its major energy-related systems (such as lighting, hot water, and HVAC systems). These physical and structural elements have a significant impact on how efficiently energy is used within a building regardless of how the building is operated or the behavior of its occupants. The Asset Score normalizes for operational and occupancy variables, and does not require users to collect energy consumption data.
What types of buildings can be scored using the Asset Scoring Tool? The Asset Score can be used for new construction projects and existing buildings with the following commercial and residential uses: Office, retail, multifamily (low and high-rise), assisted living, city hall, community center, courthouse, educational (including K-12 schools), house of worship, library, lodging, medical office, parking garage, police station, post office, senior center, warehouse (unrefrigerated), and buildings with mixed uses of any of the above types.

Future versions of the Asset Score will score buildings with more complex systems, such as freestanding data centers, laboratories, refrigerated warehouses, hospitals, and food service facilities. Single-family homes and attached homes can be scored using DOE's Home Energy Score. Visit www.homeenergyscore.gov or email homeenergyscore@ee.doe.gov for more information.

Who can use the Asset Score? The Asset Score is intended for use by a diverse group of stakeholders, including building owners, third-party property and facilities managers, energy services companies and consultants, utility program administrators, architects, building engineers, and state and local governments. Energy services companies and consultants can integrate their tools seamlessly with the Asset Score through an application programming (API) interface found here.
Is there a cost to score a building? There are no hard costs. The Asset Scoring Tool and Asset Score Report generated by the tool are free to all users. The only cost associated with scoring a building is the time required for the user to collect and enter the building data into the tool.
How do the Asset Score and ENERGY STAR® Portfolio Manager work together? The Asset Score is intended to be complementary to Portfolio Manager. An ENERGY STAR Portfolio Manager score enables the comparison of buildings based on their energy consumption, as indicated by actual energy bills. The Portfolio Manager score reflects the energy efficiency of a building’s physical structure and its systems, as well as how efficiently it is operated and maintained.

The Asset Score reflects the energy efficiency of a building based solely on its design, construction, and energy systems. The Asset Score normalizes for operational and occupancy factors, enabling users to identify specific opportunities to invest in energy upgrades. Using both tools gives users powerful information that can inform both energy upgrades and improvements in building operations.

Does DOE verify Asset Scores, or recognize buildings with outstanding scores? Not at this time. DOE does not provide verification for Asset Score inputs or outputs, or have a recognition program for energy-efficient buildings. In the future, DOE may consider giving users the option to obtain a verified score which would require some type of verification of the data submitted as well as potential eligibility requirements for the individual submitting the data. DOE is also considering a recognition program for buildings that demonstrate outstanding energy efficiency.
Is there a minimum size threshold for buildings that can be scored? No. The goal is to make the Commercial Building Energy Asset Score system equally applicable to small and large commercial buildings.
What information will be available for the public and what will be kept confidential? The sharing of the information is up to the discretion of the individuals submitting the data and scoring the buildings. DOE has no intention of disclosing any information entered into the Scoring Tool that can be used to identify a specific building without the consent of the owner of that information. However, DOE will likely use aggregated information about the buildings for statistical analysis. Individual building data will not be identifiable.
How was the Asset Score developed? The Asset Score was developed by the Pacific Northwest National Laboratory and the U.S. Department of Energy. DOE administered two rounds of pilot testing with diverse user groups in 2012 and 2013. The pilot testing and user feedback significantly influenced the technical development of the tool.

 

Asset Score Scale

What scale is used for the Asset Score? The Asset Score uses a 10-point scale to evaluate the energy efficiency of a building’s physical characteristics and major energy-related systems. The point value is assigned based on a building’s predicted source energy use intensity (EUI) according to the energy simulation results. Scores are rounded to the nearest half-point increment (i.e., “6”, “6.5”, “7”, etc.) A score of 10 is the highest achievable score. It represents the lowest expected energy use for a building of a particular use type that is achievable using current building energy efficiency technologies without renewables.
Are all buildings scored on the same exact scale? No. Every building is scored on a 10-point scale, however the underlying EUI structure for each scale varies by building use type. This ensures that buildings are scored fairly by accounting for differences in standard operating conditions between use types.
Is the Commercial Buildings Energy Consumption Survey (CBECS) used as a baseline for the scoring scale? No. A building's asset score is independent of the CBECS data because the Asset Scoring Tool evaluates a building on its own merits rather than against a population of other buildings. DOE uses CBECS and other building databases only to ensure that the 10-point scale developed for each building type can accommodate the wide range of buildings currently in the U.S. building stock.
Is there a reference point or baseline building associated with some point on the scale? No. A building's Asset Score is based only on the modeled EUI estimate generated by the Asset Scoring Tool. It is not dependent on a baseline building.

 

Scoring Methodology

What metrics are used to determine the score? The Asset Scoring Tool runs an energy simulation using the building data submitted by the user to generate a site- energy based estimate of energy use intensity (EUI) for the building. This site EUI is then converted to a source EUI. Source energy takes into account the building's energy use as well as losses that result from transmission and distribution. The Asset Scoring Tool then generates a score for the building based on its estimated source EUI. In order to allow equivalent comparisons of buildings across the U.S., the Asset Scoring Tool applies a weather adjustment to those energy uses that depends on climate (e.g., heating, cooling). For example, two buildings with different source EUIs in different parts of the country may actually have the same final Asset Score given that a building in a harsher climate will use more energy than one in a temperate climate. In addition to the Asset Score, the Asset Score Report provides other metrics including site and source energy use separated out by fuel types, and system-level performance indicators, among other information.
What building components are considered in scoring the building? The Asset Score takes into account the physical characteristics of the building as built and its overall energy efficiency, independent of occupancy and operational choices. The physical characteristics include the building envelope and the mechanical and electrical systems. The Asset Score also takes into account if a building has controls such as daylighting controls and occupancy sensors, and variable air volume terminal units. The Asset Score applies standard assumptions regarding how these controls are operated. The Asset Scoring Tool also applies standard assumptions concerning miscellaneous loads (e.g., office equipment, vending machines) based on building type.
Are greenhouse gas emissions reflected in the score? No. Greenhouse gas emissions are not used in the calculation of the score.
Are energy and operational costs reflected in the score? No. Building-specific energy and operational costs are not included in the calculation of the building score. The Asset Score Report contains estimated annual building energy usage and estimated savings associated with identified energy efficiency measures. These estimates are based on average regional utility rates and standard assumptions about operational factors such as occupancy density, hours of operation, and miscellaneous loads (such as office equipment).
Does the Asset Scoring Tool compute the Asset Score with or without on-site renewable energy systems? Currently, the Asset Scoring Tool does not include on-site renewable energy generation in the EUI calculation. DOE is evaluating different means to address on-site renewable energy generation in the next version of the Asset Scoring Tool.
Does the Asset Score include information on water use or other green building features? No. Water use is not included in the calculation because energy is the focus of the Asset Score. The energy model includes a calculation of the energy used to heat domestic water assuming a fixed amount of water consumption per occupant.
Does the Asset Scoring Tool account for the year that equipment is installed and for performance degradation? Yes. The Asset Scoring Tool accounts for the year that equipment was installed when estimating the equipment efficiency. Performance degradation is not considered because it is affected by maintenance and many other factors.
Does the Asset Scoring Tool account for different occupancies, building additions, and renovations? Occupancy is standardized across the model to allow apple- to-apple comparisons of buildings. It assumes the building is fully occupied with normal operating hours based on building type. Building additions and renovations are accounted for when scoring the building as long as the user includes the relevant information.
Does the Asset Scoring Tool use a standard set of operating conditions? What are those standard operating conditions? Yes. Buildings are modeled using a standard set of operating conditions. DOE uses recognized standards such as those defined by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). A complete description of these assumptions can be found in the Operational and Equipment Sizing Assumptions document.
How is building location assessed? Does the energy simulation tool normalize energy use for weather? The Asset Scoring Tool uses Typical Meteorological Year 3 (TMY 3) data to model a building's projected energy use and account for climatic differences between specific locations. Each building is assigned a specific weather location based on its zip code.
How does the Asset Score account for the effect of local climate on a building's energy use? To account for climate variability and allow a fair comparison of buildings in different locations, the Asset Scoring Tool applies "adjustment coefficients" to energy uses that are sensitive to weather before calculating a building's score. These adjustment coefficients (sometimes referred to as "multipliers") were established by analyzing energy simulations of ASHRAE Standard 90.1-2004 compliant buildings in 1,008 U.S. weather station locations. The adjustment coefficients are unique for each of the 1,008 weather locations. Most use types, except for warehouse and parking garage, use the same set of weather coefficients. To calculate a building's Asset Score, the tool runs an energy simulation of the building, estimates the site energy use intensity (EUI) associated with each of the building's HVAC loads (heating, cooling and fans), and then applies weather coefficients to EUIs based on a building's location. The adjusted EUIs, along with the other weather- independent EUIs (e.g. lighting) for the building, are then combined to determine the building's Asset Score.

Compared to a heating/cooling degree-days-based approach for weather normalization, which often relies on regression analysis of a large amount of measured energy use data and focuses mainly on dry-bulb temperature, simulation-based coefficients can account for other climatic factors such as wind speed, humidity, insolation, etc. In addition, by using energy simulation, weather-sensitive end uses can be separately examined from base loads such as lighting and miscellaneous loads.

What is the basis of the software that is being used to model the building's energy use? What simulation guidelines and procedures might be proposed for the Asset Score? The Asset Scoring Tool uses EnergyPlus as its centralized energy modeling engine, however tool users do not need to interact directly with EnergyPlus. Users enter a limited set of building data into a user-friendly interface and obtain the Asset Score Report through the web-based tool. Therefore, no specific modeling guidance is necessary.
Does the Asset Scoring Tool perform building simulations in real time, or does it look up pre-simulated values? The Asset Scoring Tool runs real-time simulations.
How did DOE determine what building information needs to be entered into the tool? DOE worked with the Pacific Northwest National Laboratory (PNNL) and the National Renewable Energy Laboratory (NREL) to conduct a sensitivity analysis and better understand what level of data is necessary to provide meaningful results. The number of required data inputs was determined based on this analysis.
Is there a detailed list of required building data to be collected and inputs provided in the Web-based tool? Yes. A Data Collection Form that lists all data fields is available on the website. Required data inputs are shaded green. Detailed information on data collection is contained in the Asset Score Data Collection Forms, available as a lite version and a full version.
How does the model deal with mixed-use properties? To score a building with multiple use types, the Asset Scoring Tool first calculates a score for each portion of the building dedicated to a specific use type. Then, the Asset Scoring Tool generates an overall score for the building by prorating the scores associated with each use type according to that use type's square footage.
Does the Asset Scoring Tool provide scores for individual systems in a building? No, the Asset Score is intended to reflect the whole building. However, the Asset Score Report includes system- level evaluations for the building envelope, lighting, cooling and heating systems, and service hot water systems.
Is there an offset for passive design elements? No. Passive design elements are considered on their own merit rather than specifically as a "passive element." For example, proper window orientation and shading devices reduce the total energy consumption of a building and are reflected in the Asset Score. However, the Asset Scoring Tool does not model passive cooling strategies such as opening windows, evaporative cooling, etc.
Can the EUI (kBtu/ft2) value provided by the Asset Scoring Tool be directly compared to the EUI number derived from ENERGY STAR Portfolio Manager? The EUI provided by the Asset Scoring Tool reflects modeled energy use under standard operating conditions; the EUI derived from Portfolio Manager is measured energy use under actual operating conditions. Therefore, these EUI values are not directly comparable.
Do you need to model different sub-types within a building? Most buildings with regular geometry and one set of HVAC systems can be modeled as a single space. For example, it is unnecessary to separately model meeting rooms, lobbies, and offices within an office building. The Asset Scoring Tool can model more complex buildings that are made up of sections with distinctly different physical configurations or energy features. When a building has sections with different number of floors or served by different types of HVAC systems, users can create multiple blocks and define properties for each block.

 

Identified Opportunities for Energy Efficiency Upgrades

How are the recommendations for energy efficiency upgrades determined? Upgrade opportunities are considered in a package using an optimization process based on life-cycle cost (LCC) analysis. Building LCC analysis algorithms provided by the National Institute of Standards and Technology are used in the optimization process to rank recommendations. Interactive effects between measures are considered. The economic assumptions used in the LCC analysis (0% discount rate and 25 years of study period) were selected to produce a diverse, comprehensive list of upgrade opportunities, and do not attempt to match a user's unique set of economic expectations. Users will need to consider local costs of upgrades and their own financial perspectives when deciding whether to pursue specific opportunities.
How does the Asset Score ensure upgrade opportunities provide useful guidance and keep up with technological advances? The Asset Scoring Tool considers the limitations of the existing building construction, accounts for applicability of various HVAC systems, and performs life-cycle cost analysis. All these capabilities help ensure that the identified opportunities are practical. The modeling tool and upgrade opportunities library will be maintained to keep up with the technological advances. Updates to the upgrade opportunities library may affect the upgrade recommendations and a building's potential Asset Score, but will not change a building's current Asset Score.

 

Quality Assurance

How does DOE maintain quality control for the Asset Scoring Tool? The Asset Score includes several quality assurance measures. First, the tool’s energy modeling approach is a centralized real-time simulation using EnergyPlus. Although individual users gather and enter the data onto the web- based tool, the modeling itself is standardized. Second, the tool uses an established and standardized methodology for data collection to ensure consistency with other existing standards. Third, the user interface includes automated checks and provides a warning if entered data appears incorrect or incomplete. Users are also provided with online help, data input checklists, and other useful data collection tools.
How are accuracy and consistency of Asset Score inputs and outputs ensured? DOE is considering different approaches to ensure the quality of inputs, such as establishing a professional verification program. The tool outputs are generated through a centralized modeling tool, which ensures consistency and replicability of the results.
How detailed are the input requirements? DOE's objective is to find the level of detail that provides a reasonable balance between accuracy and data collection burden. Fewer required inputs minimize the effort required to collect data. However, using a larger number of inputs can increase the efficacy of the simulation and results. The program provides consistent definitions for data requirements and will continue to take steps to encourage consistent data collection and measurement.

 

Connection to Other Tools

Can the Asset Score be used with ENERGY STAR Portfolio Manager? ENERGY STAR Portfolio Manager users can import their building information via a link in the Asset Scoring Tool to avoid repetitive data entry.
Can users import building data into the Asset Score through an API? Yes. Software companies can integrate their tools seamlessly with the Asset Score through an application programming (API) interface found here.
Will the Asset Scoring Tool allow for comparisons to local code or other user- defined reference points? The Asset Scoring Tool is being designed to allow for third-party applications to interface with the system. These third-party entities may develop applications that would allow comparisons to local codes or other user- defined reference points. The Asset Scoring Tool, however, does not do this independently.