There seems to be some doubt about Office 2016 when to install 64-bit version of office vs 32-bit

Limitations of the 64-bit version of Office

The 64-bit version of Office may perform better in some cases, but there are limitations:

• Solutions using ActiveX controls library, ComCtl controls won’t work.
• Third-party ActiveX controls and add-ins won’t work.
• Visual Basic for Applications (VBA) that contain Declare statements won’t work in the 64-bit version of Office without being updated.
• Compiled Access databases, like .MDE and .ACCDE files, won’t work unless they’re specifically written for the 64-bit version of Office.
• In SharePoint, the list view won’t be available.

If you have specific add-ins that you use in the 32-bit version of Office, they may not work in 64-bit Office, and vice versa. If you’re concerned, check your current version of Office before installing the new one. Considering testing the add-in with 64-bit Office, or finding out if a 64-bit version of the add-in is available from the developer.

The 64-bit version of Office has some limitations, but is the right choice when:

• You work with extremely large data sets, like enterprise-scale Excel workbooks with complex calculations, many PivotTables, connections to external databases, PowerPivot, PowerMap, or PowerView. The 64-bit version of Office may perform better for you.
• You work with extremely large pictures, videos, or animations in PowerPoint. The 64-bit version of Office may be better suited to handle these complex slide decks.
• You work with extremely large Word documents. The 64-bit version of Office may be better suited to handle Word documents with large tables, graphics, or other objects.
• You’re working with files over 2GB in Project, especially if the project has many subprojects.
• You want to keep the 64-bit version of Office that you’re already using. The 32-bit and 64-bit versions of Office programs aren’t compatible, so you can’t install both on the same computer.
• You’re developing in-house Office solutions, like add-ins or document-level customizations.
• Your organization requires Hardware Data Execution Prevention (DEP) be enforced for Office applications. DEP is a set of hardware and software technologies that some organizations use to enhance security.