As far I am aware, the Building Code requirements in the USA, with respect to Cross Laminated Timber (CLT), were updated and incorporated into the 2015 National Design Specification (NDS) for Wood Construction. It is this NDS for Wood Specification document that paved the way, as an important guideline and reference, for the incorporation of CLT as a recognized and utilized Building Code compliant and General Construction Industry accepted Construction Material into the 2015 International Building Code (IBC) and also the more recently updated IBC. The CLT changes that were incorporated include the assembly of exterior walls, floors, partition walls and roofs among others. Additionally, in order to adhere to the minimum structural performance standards, the IBC 2015 requires that the structural CLT products are in compliance with the standards and the requirements, as also prescribed and specified by ANSI/APA PR 320.

As an interesting fact, please note that as of this time (October 2020), to the best of my knowledge, the current world's tallest timber building is reported to be 85.1m (280 ft) and is located in Norway, Europe.

Are you aware of other important Cross Laminated Timber (CLT) Building Codes other than the 2015 NDS for Wood Construction, 2015 IBC, and ANSI/APA PRG 320 ?

Additionally, are you aware of any other substantial Timber Structures that have been completed or are planned to be build, or exceed the currently reported 85.1m (280 ft) ?

Let's keep on innovating :).