The gassing facilities that Globočnik established at Belzec soon after his 13 October meeting with Himmler were designed by T4 programme personnel assigned to him. They used carbon monoxide, as the T4 programme had done. Before it became an extermination camp, Belzec had been part of Himmler's and Globočnik's Burggraben project. The construction of three more death camps, Sobibor and Majdanek in the Lublin district and Treblinka at Małkinia Górna, followed in 1942. Globočnik was complicit in the extermination of more than 1.5 million Polish, Czech, Dutch, French, Russian, Slovak, German, Portuguese, Turkish, Spanish and Austrian Jews, as well as a smaller number of non-Jews, in the death camps which he organised and supervised.
He exploited Jews and non-Jews as slave labourers in his own forced labour camps. He was responsible for seizing the properties and valuables of murdered inmates while in charge of Operation Reinhard. Although other arms of the Nazi state were also involved in the overall management of the greater concentration camp system, Globočnik had control over the Aktion Reinhard camps, and any orders that he received came directly from Himmler. From 1942–1943 he also oversaw the beginning of the Generalplan Ost, the plan to expel Poles from their lands and resettle those territories with German settlers (see Zamość Uprising). On 9 November 1942, Globočnik was promoted to SS-Gruppenführer and Generalleutnant der Polizei.