Key Performance Indicators

for Commercial Buildings

What are the code and policy actions involving energy monitoring and performance indicators? NBI participates in energy code development and monitors other policy actions that influence the use of measured performance data. Notably many energy codes are addressing building energy metering in ways similar to the NBI building levels. The codes use differing approaches to require detailed metering on certain building systems or end-uses. Here we examine the current code and policy activity in energy monitoring by building level (i.e. complexity of monitoring approach).

Policy Legislation is occurring in many states and municipalities to encourage the reporting of measured energy data by commercial building owners and managers. There are a variety of approaches to the reporting requirements but none is contemplating energy usage reporting that is more frequent than annual energy use, typically compiled through monthly utility meter data. The map below shows states with energy disclosure activity. More information is available at: www.buildingrating.org/

U.S. Building Benchmarking and Energy Disclosure Policies Building Disclosure

Seattle Portland

WASHINGTON VERMONT Burlington

MINNESOTA

MASSACHUSETTS

Minneapolis SOUTH DAKOTA

MICHIGAN

NEW YORK

Chicago San Francisco

OHIO

Philadelphia

UTAH Denver

CALIFORNIA

Washington, DC

KANSAS Santa Fe

Cambridge Boston CONNECTICUT New York City

Boulder

San Jose

MAINE

Montgomery Co., MD Arlington, VA

TENNESSEE

ALABAMA Austin

Orlando, FL

ALASKA HAWAII

Updated 2/25/2013

Commercial Policy Adopted

Public Buildings Benchmarked

Commercial Policy Interest

Residential Disclosure Adopted

Green Button Though not a policy-driven activity, the Green button represents a technological approach to increasing availability of utility data. The industry-led effort has developed a technical standard under a “public-private partnership supported by the Commerce Department’s National Institute of Standards and Technology. Voluntary adoption of a consensus standard by utilities across the nation allows software developers and other entrepreneurs to leverage a sufficiently large market to support the creation of innovative applications that can help consumers make the most of their energy usage information.” More information is available at: http://www.greenbuttondata.org/

Codes and Policy

Key Performance Indicators

for Commercial Buildings Codes

Within the realm of building codes, there is action primarily at two levels of energy monitoring as shown in the table below. Building Codes govern the way buildings are built, however, they have little authority over how they are operated. Therefore, codes efforts focus on the metering equipment itself and elements of construction that will impact energy monitoring down the line. The codes cannot require that energy usage data be disclosed to any party; the codes cannot even require that the equipment be used. But importantly the code gets the monitoring equipment into buildings, which removes one of the greatest obstacles to the effective monitoring of energy usage. Likewise, through making buildings able to more readily accommodate the installation of monitoring equipment in the future, one of the largest obstacles to retrofitting buildings with energy monitoring equipment is also removed. Building codes in the United States are not centralized. They are established at the state level, with authority sometimes delegated by the states to cities, counties, etc. Therefore, there is a diversity of approaches to energy monitoring moving forward simultaneously. There are two national “model” codes in the United States—code language that is made available for states to adopt and/or adapt—so some of the policy efforts transcend state lines. These codes, ASHRAE 90.1 and the International Energy Conservation Code (IECC), are influential in placing requirements for metering on commercial projects. Activity at Building Level Code

0

ASHRAE 90.1 IECC IgCC ASHRAE 189.1 Title 24 WA State OR State (Reach Code)

I

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II

III A

B

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Level 0 - Whole-Building Monthly Building codes have little impact on Level 0 energy monitoring. Codes do impact the installation of utility meters, the equipment required for utility bill energy monitoring. However, those requirements are generally only triggered when a meter is installed, and they do not generally require that a building even have a utility meter.

Level I – Whole-Building Electric Interval Data Several different state and model codes have provisions requiring whole-building interval data monitoring of some or all forms of energy at the whole-building level either already in place or under consideration.

ASHRAE 90.1 ASHRAE 90.1 is a continuously updated standard with milestone releases every three years. These milestone releases are evaluated by the U.S. Department of Energy and are typically adopted as code. The 2010 version of 90.1 does not have any whole-building interval data monitoring requirements. However, Addendum BN adds whole-building energy monitoring of electricity to the standard and will be part of the 2013 version with requirements for 15-minute metering intervals and 36 months of storage capacity. The ASHRAE committee is also considering Addendum BZ which would extend the whole-building metering requirements to natural gas, fuel oil, propane, steam, chilled water and hot water with one-hour interval metering. If this addendum is included, these requirements will be added to the 2013 version of 90.1 as well. Codes and Policy

Key Performance Indicators

for Commercial Buildings IgCC

The International Green Construction Code (IgCC) is an “overlay” code1 published by the International Code Council. The inaugural 2012 version has a full array of energy monitoring equipment requirements for commercial buildings. It requires whole-building metering of all energy forms that enter a building. This list is very comprehensive and includes electricity, gaseous fuels (such as natural gas, propane, etc.), liquid fuels, district energy, combined heat and power, renewable energy, waste energy recovery, and even solid fuels (such as firewood or charcoal). The minimum metering interval is one hour, and the meters must be connected to a data acquisition device that is capable of storing at least 36 months of data.

ASHRAE 189.1 ASHRAE Standard 189.1 is a standard that can also be used as a model code. Its requirements for wholebuilding energy monitoring are less comprehensive than the IgCC, covering only electricity, gas, geothermal, district energy, thermal and solar electricity. The requirements are also only triggered once the energy service to the building exceeds a certain capacity. For instance, the threshold for electricity is 200 kVA. 189.2 also requires a minimum interval of one hour and a minimum storage capacity of 36 months in addition to but also prescribing that the monitoring devices automatically transmit data to the data acquisition device at least once a day.

IECC The International Energy Conservation Code does not currently have any whole-building energy monitoring requirements. However there is a proposal that will be considered for the 2015 edition that would introduce new requirements. The proposal is very similar to the requirements of the IgCC and ASHRAE 90.1, with similar requirements for data storage and measurement intervals, and applies to electricity, gaseous and liquid fuels, district energy (defined as any system that serves multiple buildings), and on-site renewable energy production.

California California’s energy code, Title 24, includes requirements for the whole-building and user-accessible meters for electricity. The provisions require different metering capabilities at different electrical service sizes. Title 24 does not specify requirements for data storage or measurement interval; however, buildings with larger electrical services (greater than 250 kVA) are required to have meters capable of recording historical peak demand data. Buildings with very large electrical services (greater than 1,000 kVA) are required to have meters capable of recording the kWh used during the different rate periods. This essentially requires some kind of data storage device at least for buildings with larger electrical services.

Washington State Washington requires the whole-building energy monitoring of electricity, gaseous and liquid fuels, district energy and on-site renewable energy. Solid fuels delivered to the site are specifically exempted. The requirements are triggered by a threshold based on building size – 20,000 sf – rather than service size. It also requires one-hour intervals and a 36-month storage capacity.

Oregon Reach Code The Oregon Reach Code has whole-building energy monitoring requirements based on the IgCC. It differs from the IgCC by removing requirements for the measurement of solar thermal and waste energy recovery.

1

An overlay code is adopted on top of other codes already in place in the jurisdiction. Although it touches on topics also covered by the plumbing code, energy code, mechanical code, etc., it is meant to complement those underlying codes and cannot replace them.

Codes and Policy

Key Performance Indicators

for Commercial Buildings

Level II – Whole-Building Interval Data with Tenant Plug Load System Currently no code is considering the use of sub-metering only on the tenant plug loads as is recommended in Level II. Since code development tends to involve some backsliding of proposed code changes it is possible that this could be a fallback to more aggressive proposed changes as are occurring in Level III.

Level III – System-Level Interval Data Analysis Several different state and model codes have provisions requiring some level of sub-metering. Approaches to submetering have been dominated by two models. Under the first (Level III A), sub-metering is required whenever a load reaches a certain threshold. Under the second (Level III B), sub-metering requirements define a discrete number of system or load types and then require measurement of each of those load types. Each code approach embraces one of these models or a hybrid of the two.

Level III A – System-Level Interval Data Analysis—With Permanent Sub-meters ASHRAE 90.1 Addendum BZ to ASHRAE 90.1 requires sub-measurement only of electricity. It defines four load types that must be measured: HVAC systems, interior lighting, exterior lighting and receptacles. It exempts smaller buildings (below 25,000 sf ), smaller tenant spaces (below 10,000 sf ), dwelling units, critical equipment branches, lodging, restaurants and smaller residential buildings (below 10,000 sf of common area). Addendum BN of ASHRAE 90.1-2013 makes allowances for some mixing of the load types, permitting up to 10% of the energy in any category to be from other load categories.

IECC The proposal for the 2015 IECC is modeled directly on the ASHRAE 90.1 language. The only difference is that the allowable amount of load type mingling is 5% rather than 10%.

IgCC The IgCC has comprehensive sub-metering requirements for the same set of energy types as its whole-building requirements. They are triggered at a size threshold of 25,000 sf. It defines five load types: lighting, HVAC, plug loads, large process loads and a miscellaneous category for anything that doesn’t fit the first four.

ASHRAE 189.1 ASHRAE 189.1 has sub-metering requirements based on system service thresholds and fuel type. The requirements capture HVAC systems (greater than 100 kVA / 500,000 Btu/h), people moving equipment (greater than 50 kVA), lighting (greater than 50 kVA), electric plug and process loads (greater than 50 kVA) and gas or district process loads (greater than 250,000 Btu/h).

Washington State Washington State’s sub-metering provisions are subject to the same size threshold as the whole-building requirements: 20,000sf. Washington requires sub-metering for two defined load types: HVAC and water heating. The requirements also have some significant exceptions. All equipment that serves only a single dwelling unit is exempt. All life safety equipment is exempted. Tenant spaces smaller than 2,500 sf are exempted. 120 volt HVAC equipment is exempt, as is 208/120 volt equipment in a building where the main service is 480/277 volt. Any water heating equipment below 50 kW is also exempt, effectively exempting all but large, process-scale service hot water systems.

Codes and Policy

Key Performance Indicators

for Commercial Buildings Oregon Reach Code

The Oregon Reach Code’s sub-metering requirements are also based on the IgCC. It differs from the IgCC in the definition of the load types. It defines for load types that must be sub-metered: lighting, HVAC, plug loads and large process and miscellaneous loads. Those large loads are any single load whose peak demand exceeds the whole building’s peak demand.

Level III B–System-Level Load Segregation—Without Permanent Sub-Metering Several codes and code efforts have an intermediate step between whole-building metering and sub-metering. These provisions focus on requiring that buildings be built in such a way that they can easily and effectively have sub-metering equipment installed in the future. This reduces costs in two ways. It removes the cost of the actual sub-meters from the project and, through gathering and segregating load types, makes the later addition of submeters much more cost-effective through limiting the number of meters required.

IgCC Load segregation was pioneered in the IgCC. It requires that all of the load types defined for the submetering requirements also be segregated from each other throughout the building. While the sub-metering requirements have a size threshold, the load segregation requirements apply to buildings of all sizes. The IgCC makes an exception for any building that has a metering system that can measure all of the load types separately.

California Title 24 does not require sub-metering, but it does have load segregation requirements. It defines load types ranging from HVAC to people movers to electric car charging stations. The segregation of each load type is triggered by one of the four service size thresholds used for Title 24’s other metering requirements.

Oregon Reach Code Like the other energy measurement requirements, the Oregon Reach Code’s load segregation requirements are based on the IgCC. The only difference is that it uses its own set of load types, the same as used in its submetering requirements.

As commercial building techniques improve and technology costs decrease there is an opportunity to build in standardized analysis to new construction and even add to existing buildings. This guide, funded by the California Energy Commission’s PIER program, provides an overview of the New Building Institute’s KPI approach and answers to some basic questions. More detailed information including specification language that designers or owners can use in construction documents to specify the exact approach for their project, can be found at: www.newbuildings.org/kpi

Codes and Policy