Baselines
Projects must demonstrate a reduction in total net annual energy consumption as compared to a project-specific baseline. Baselines can be established by using a current typical building with a comparable climate, floor area, use, and occupancy. Project teams must use approved tools, including Zero Tool or the EDGE tool, to calculate energy baselines.
If a project has more than one Typology, for example, a renovation project with an addition, the energy baseline can be created by using a weighted average based on Project Area and the required reduction percentages.
Baselining Tools
The list below comprises the tools currently approved to develop project-specific energy baselines. If a project team wishes to use an alternative data source or methodology that is more locally relevant for establishing an equivalent baseline, it must be submitted as a Request for Ruling for preapproval. Requests must include a description of the tool, the source of the data, date of the dataset, and why the alternative is more accurate or relevant for the project (typology, country, region, etc.). The baseline and target EUI generated by the proposed tool must also be provided with the request. Additional tools have been approved for Oceania, Singapore, and Minnesota in the U.S. (see Regional Equivalency Baselines).
- Zero Tool is a web-based tool, created by Architecture 2030, that calculates a building-specific baseline Energy Use Intensity (EUI), target EUI, and GHG emissions based on a reduction goal. To generate these values, the tool utilizes climate, type, and occupancy-normalized energy consumption data from the 2003 U.S. Commercial Building Energy Consumption Survey (CBECS) dataset. Values can be generated for projects in North America, though the tool provides guidance on how to generate equivalent values for projects in other countries.
- EDGE is a web-based tool, developed by IFC World Bank Group, that draws on various data sources to generate an energy baseline. Results can be generated for projects in Africa, Asia, Europe, and North and South America. The tool sources energy consumption trend data from local energy efficiency codes when applicable or otherwise uses the ASHRAE 90.1-2007 standard to generate a baseline case.
Data to be entered into the selected baselining tool, such as ZIP/postal code, building use type(s), and gross floor area(s), must be as detailed as possible so that the resulting baseline is as accurate as possible.
Building-Specific Baseline Data
The following tools may also be used to generate the baseline EUI for the specified building type:
Multifamily Housing
EnergySTAR Portfolio Manager – a web-based tool developed by EnergySTAR that measures and tracks energy performance within buildings.
Laboratory Projects
Laboratory Benchmarking Tool – a web-based tool developed by kW Engineering, the Berkeley Lab (LBNL), and the International Institute for Sustainable Laboratories (I2SL).
Energy Targets
The Zero Carbon standard defines operational carbon as the total energy required to operate a building, without reference to how that energy is supplied. Accordingly, energy provided by renewable systems, either on-or offsite, may not be factored into achievement of the operational energy efficiency requirements under the Zero Carbon standard.
During the twelve month performance period, projects must perform at the established energy efficiency target.
- Alternatively, project teams may also propose an energy target that meets an equivalent level of performance to the established target. Teams should submit this proposal as a Request for Ruling for preapproval.
- Project teams are also permitted to utilize a locally-defined, net-zero equivalent energy target that is equivalent to or more stringent than the established energy efficiency target. The following location-specific alternative energy efficiency targets have been approved:
Table ZC-5 Local EUI Targets
[1] 2018 International Energy Conservation Code, Chapter 3, Section C301
Interior
Energy Baseline and Performance Scope
Energy loads that are within the tenant space and within the tenant’s control must be included in the energy baseline and performance calculations. The percent reduction should be calculated using this scope-dependent baseline. An Interior project may not exclude energy consuming loads within their tenant space because they do not plan to upgrade them.
Shared base building systems, including district energy systems, out of the project’s scope and control, such as HVAC, may be uniformly excluded from the target EUI calculations, anticipated performance calculations, and metering strategy at the team’s discretion.
Teams including base building energy loads in the energy efficiency calculations may demonstrate performance by calculating this HVAC energy using air flow meters to measure conditioned air serving the tenant space relative to total conditioned air for the building, or by determining a proportionate share based on the ratio of the tenant’s rentable square footage to the total rentable square footage of the building.
Note that independent of the approach used for energy reduction calculations, Interior projects must account for a proportionate share of HVAC energy use for the purposes of offsetting the full operational energy of the project.
Baseline Modeling
Interior and Existing Building projects may use ASHRAE 90.1- 2010 to conduct their energy modeling. Loads that are eligible for exclusion may be omitted from the energy model or removed by post-processing.
Alternatively, the baseline may be created using Zero Tool or the IFC’s EDGE tool. In this case, the baseline should be created using data for the entire building. The target EUI can be calculated by using a tenant-proportionate share of the whole-building baseline. For projects where other building uses would disproportionately influence the target EUI–for example, a building containing both low-EUI office space and high-EUI lab space–the team may propose an alternative baseline design in Zero Tool or EDGE Tool that more accurately reflects the project’s energy profile.
An EUI generated with Zero Tool or EDGE Tool will generally include base-building energy use, such as HVAC, which can be excluded from Interior projects if it is outside their control. The team may choose to retain these loads in the EUI calculations and expand the scope of energy metering and performance tracking to match, or they may propose a methodology to remove these loads from the EUI, subject to approval by Living Future. The data granularity in the EDGE tool may facilitate these calculations.
Where a tenant-proportionate share must be determined, base the calculations on the percent of the net-leasable area occupied by the project.
Metering
Projects must meter their project’s energy use and report it in the Energy Production and Demand Table. Although sub-metering is best practice and strongly encouraged in order to better understand and troubleshoot energy end uses, it is not required for certification.
Interior projects must only meter energy associated with their interior scope. In cases where that data is unavailable, a tenant-proportionate share of the energy metering data from the whole building may be used. If whole building data is not available, project teams should propose a metering approach and submit a Request for Ruling for preapproval. In either case, ensure that the metered loads coincide with the loads included in the target EUI calculations.
Net Annual Energy Balance
Energy use and production do not need to balance each month, but do need to balance to net zero production or better over the course of the 12-month performance period.
Project Energy Needs
All equipment and energy-using systems related to any part of the building program (including process energy) and used during building operations must be included in the energy budget for the project. The building must function as intended and meet the energy requirements over the 12-month performance period. Energy used during construction does not need to be included in the project’s operational energy budget.
Note that use of exception EC-014 Emergency Power Systems requires that any energy used by an allowed generator be included in the project’s energy consumption calculations.
Surplus Energy
Renewable energy generated on site that is in excess of the net balance required for certification and that goes back to the grid may be applied toward the embodied carbon offset requirement in accordance with all of the following:
- The renewable energy system must have a predicted life of at least 25 years;
- The net surplus energy generated during the 12-month performance period (PP kWh) must be calculated and converted to tCO2e using a regional grid factor from EPA’s Emissions & Generation Resource Integrated Database (eGRID) Summary Tables or equivalent resources for international projects (see Calculations); and
- Up to 10 years’ worth of the converted excess performance period tCO2e (PP tCO2e) may be credited toward the carbon offset.
Vehicle Charging Energy
The project energy budget may exclude any vehicle charging energy associated with the project, as long as separate metering demonstrates that the amount excluded from the overall energy use of the 12-month performance period is equal to that used for vehicle charging. This exclusion is to encourage projects to have public charging stations that support non-project or non-tenant-owned electric vehicles.
If separate metering of charging stations is not feasible, project teams may track the miles driven by the vehicles over the performance period and convert miles driven into electricity using the rated mileage of the vehicles charged. If distance tracking is not possible, projects may use an average efficiency rate as an alternative.
