This summary document describes a set of code strategies that represent a 20% performance improvement for commercial buildings over the ASHRAE 90.1-2013 code baseline (and approximately similar savings over the IECC 2015 baseline).

As leading cities and states seek to meet their aggressive climate, energy, and decarbonization goals, they are turning increasingly to mandatory policies that require improved energy and emissions performance across their existing building stock. The most comprehensive of these policies is the BPS, in which performance thresholds are set that building owners must meet at a specified time or when a triggering event occurs. A BPS can address a range of emissions, energy and grid-related goals. This paper examines technical approaches used to set the key metrics for both buildings and fuels in performance standard legislation.

The Building Decarbonization Code is a groundbreaking tool aiming to deliver carbon neutral performance. The Version 1.2 code language from NBI serves as a building decarbonization overlay to the 2021 International Energy Conservation Code (IECC) and is now compatible with ASHRAE 90.1. It is designed to help states and cities working to mitigate carbon resulting from energy use in the built environment, which accounts for 39% of U.S. emissions.

This guide is part of a larger project focused on the technical development of advanced energy codes and policies, and on support for jurisdictions to adopt and implement these approaches.