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.

Any addenda currently out for public review can be found here.

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 Addenda, sorted by year, are available for download below. To comment on public review drafts during the listed comment period, obtain the necessary forms and instructions on the ASHRAE Website.

Please note this page was last updated on January 5, 2020, and is believed to be current as of that date.

Addenda Overview

ASHRAE 135 – The BACnet Standard

ASHRAE 135.1 –The BACnet Companion Standard