Heating on a PIR

[brizospark]

Just received the drawings for the new job I am going on to. A new build with a lot of small rooms

It seems that they want the heating controlled via a PIR and contactor box mounted in rooms

Has anyone installed a system like this and can anyone describe in further detail how this system works

Thanks in advance

 

[alarm man]

seems the pir is replacing/controlling the stat,tho imagine it would have to go thru a timer relay to give enough heat,never seen that set up before,it could work tho