In a direct communication, Statistics Canada explained:

These series were created by mistake when the new table was created. This variable does not exist as we do not collect the number of permits for demolitions, but only the number of units lost. 

In response, we have deleted these series from Data Buffet. If you have legacy retrievals, continued use of an old mnemonic will elicit a "series not found" error; the basket editor provides a "find and replace" tool to assist with migration.

• Concepts: 1 - HSQPMTTDEMTUM
• Geos: 48 - nation, province, CMA
• Date range: January 2018 to February 2018
• Value range: 0
• Source description: Building permits; Total demolitions; Type of work, total; Number of permits; Unadjusted

As a replacement, please use the "count of units demolished" concept which resides in the historical catalog at (Canada » Real Estate » Construction » Permits » Count of dwelling units), for example:

• HSQPMTTDEMTDUM.ICAN = Building permits: All types of work - Total demolitions - Dwelling-units demolished, (#, NSA)

Because catalog locations are subject to change, the upper-right search box on DataBuffet.com provides a "find in catalog" mode that accepts a mnemonic.