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Building Technologies

Enabling City-Scale Residential Hourly Energy Modeling

Company Name: Radiant Labs
Program Office:  Buildings
Location: Boulder, CO
Award Amount: $200,000
Project Term: 12 months
Project Status: Active
Participating Lab(s): National Renewable Energy Laboratory


U.S. multifamily buildings house 35 million households, consuming 4 quads of source energy and spending $48 billion on utility bills every year. Almost all of these households are in urban areas, where cities are taking the lead in setting aggressive energy goals. However, many cities currently do not have the data and tools necessary to identify and target opportunities to save energy in their building stock.

Radiant Labs has developed market propensity software that can utilize publicly available information such as assessor data, building permits, data on rooftop solar potential, and optional utility bill data to generate an hourly energy model and replacement timeline for all homes in a city or utility district.The tool can then determine the best candidates to target for a variety of energy-related improvements such as efficiency, fuel switching, rooftop photovoltaic systems, and electric vehicles.

Radiant Labs has been successful in using the open-source software ResStock's single-family capabilities to provide value to cities including Boulder, Colorado and Burlington, Vermont. However, lack of multifamily capabilities in ResStock is a roadblock for Radiant Labs working with New York City, San Francisco, Washington, D.C., and other cities that have expressed significant interest in working with the company. This project will allow Radiant Labs to work with the National Renewable Energy Laboratory to expand its modeling capabilities into the multi-family sector.


Radiant Labs offers data processing and an analytics engine that can quantify the existing inventory of heating and cooling equipment, water heaters, roof age, and other data to estimate a replacement timeline for those items for all homes in a given territory. This engine compiles and integrates assessor data, permit data and other building-level data that may exist in a variety of different forms and formats. The platform can perform hourly energy modeling in order to provide financial, energy consumption, and emissions analysis for every single-family home in the data set for various combinations of improvements.

Radiant Labs tools leverage ResStock, an open-source software package that uses sampling over building asset characteristic distributions to create robust sets of EnergyPlus/OpenStudio energy models for stock-level building energy analysis.


Building on the open-source OpenStudio-based ResStock platform, this project will extend publicly available ResStock modeling capabilities to the multifamily sector, enabling Radiant Labs and others to partner with cities to market and strategically deploy cost-effective energy efficiency upgrades directly to high-priority households.

In addition, other cities, companies, and utilities can use these open-source capabilities to grow their energy efficiency portfolios, thereby multiplying the impact of this project. This work also enables national-scale analysis of energy efficiency potential in multifamily buildings, which is of strong interest to a variety of stakeholders.

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