(Updated March 28, 2020). 

CISA, which is part of the U.S. Department of Homeland Security, recently updated its list of “Essential Critical Infrastructure Workforce” to include “workers performing housing construction related activities”.  Although state and local governments are ultimately responsible for determining which workforce categories are deemed essential to public health and safety in their particular area (and therefore allowed to continue to operate in the event of a shutdown), CISA’s list reflects the federal government’s view on which workforce categories should be deemed essential.  If you are seeking an exemption to continue housing construction related work under a state or local shutdown order, you should cite the updated CISA advisory list as support for your request:  View the CISA Advisory List (housing construction guidance appears on Page 15) 
CISA Guidance on the Essential Critical Infrastructure Workforce Version 2.0