providing {HEAD ~ a structure} including framing members and a sheath forming at least one cavity having {TAIL ~ a known depth} 
providing { HEAD ~ a structure } including framing members and a sheath forming at least one cavity having { TAIL ~ a known depth }
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL