Addenda are substantive changes and additions to the BACnet Standard. They go through a rigorous process including technical review, public review, formal answers to comments, and formal committee voting before publication. Once published, addenda are officially part of the BACnet Standard even though they are not in the same document. Each revision of the BACnet Standard document incorporates addenda to the prior version.

The experiences of users and implementers of BACnet have led to many constructive suggestions for improving the standard. The same can also be said about the companion standard for BACnet conformance testing. These updates are frequently issued as addenda so they can be made available without waiting for the next release of the full standard.

PDF copies of all published addenda are available for download below and on the ASHRAE website.

To comment on addenda currently out for public review, obtain the necessary forms and instructions on the ASHRAE website. The addenda can be found here.

Please note this page was last updated on May 10, 2024, and is believed to be current as of that date.

Addenda Overview

ASHRAE 135 – The BACnet Standard

ASHRAE 135.1 –The BACnet Companion Standard