Building Stock Data
The Explorer’s nonresidential building data comes from City and County Commercial Building Inventories produced by the National Renewable Energy Laboratory (NREL). These inventories can be accessed through the U.S. Department of Energy’s Open Energy Data Initiative (OEDI) here.
From these inventories we derived a modeled list of buildings along with year of construction, square footage and building type for each CA local jurisdiction.
The inventories were developed using CoStar and the Commercial Building Energy Consumption Survey. As NREL explains:
"The Commercial Building Inventories provide modeled data on commercial building type, vintage, and area for each U.S. city and county. Please note this data is modeled and more precise data may be available through county assessors or other sources. Commercial building stock data is estimated using CoStar Realty Information, Inc. (www.costar.com) and Energy Information Administration Commercial Building Energy Consumption Survey."
Energy Use Intensity (EUI) Data
The Cost-Effectiveness Explorer provides annual EUI values by fuel type:
Electricity
Natural Gas
Other fuels (a combined category including district heating/cooling, propane, and miscellaneous fuels)
EUIs are derived from three main sources:
Apartments - DOE's ResStock data
All true nonresidential building types - DOE's ComStock data
'Other' building types - California AB802 Benchmarking data
Apartment Buildings
Apartment EUIs are calculated from ResStock on a statewide basis, averaged by decade of construction. Where no construction year is available, a statewide average is applied. Due to limited modeling coverage, averages at the city or county level were not feasible.
Nonresidential Buildings
For the ten nonresidential building types, EUIs were derived based on ComStock, the U.S. Department of Energy’s large-scale commercial building modeling dataset. From ComStock, we calculated the average EUI for each Public Use Microdata Area (PUMA), for each by building type and building size bin. Where there was no ComStock data for a given PUMA-building tye-size bin combination, missing values were addressed using interpolation:
If two neighboring bins had valid values, missing values were filled in linearly.
If only one neighboring bin was available, that EUI was applied across the missing bins.
For jursidictions comprised of more than one PUMA (in whole or in part) PUMA-level results were translated to city level average by weighting the average for each PUMA by local population factors. If no ComStock data was available for any of the PUMA's for a given city, building type and size bin, we applied the corresponding county-wide average EUIs for that building type.
'Other' Building Type
Because ComStock does not include “other,” we used AB802 benchmarking data (2023) reported for 'other' buildings. We calculated City- or county-level averages where data was available; if not, statewide averages were used. Limited data availability meant that averages based also on size and vintage were not feasible.
Energy Use and Emissions Estimates
Annual site energy use is calculated for each building by multiplying floor area by its EUI (for each fuel type).
We estimated emissions for each building by multiplying the energy use estimate for each fuel type by a type specific emissions. In the Explorer, you can view and adjust the emissions factors applied via the Assumptions panel, allowing results to reflect your own jurisdictional assumptions. Open the panel by clicking the Assumption button near the top right of the page within Building Estimates.
Citations:
National Renewable Energy Laboratory. (2020). City and County Commercial Building Inventories '2019 Commercial Building Inventory - West.xlsb'. Retrieved from https://dx.doi.org/10.25984/1788089. License: https://creativecommons.org/licenses/by/4.0/
U.S. Department of Energy. (2024). ComStock [dataset]. NREL. Retrieved from https://comstock.nrel.gov
U.S. Department of Energy. (2024). ResStock [dataset]. NREL. Retrieved from https://resstock.nrel.gov
California Energy Commission. (2023). Assembly Bill 802 Benchmarking Data Reports. Retrieved from https://www.energy.ca.gov/programs-and-topics/programs/building-energy-benchmarking-program