You are all getting muddled. The drawing is by someone in 203 Prisoner of War Company. This was a WW1 Labour Battalion, formed in September 1918. They dug trenches and did other manual work, as well as looking after PoWs. They were stationed in Abbeyville, France. They then moved to St Omer, France, in January 1919.
The drawing is almost certainly the hut in which they stayed (slept at night).
Many of the men, in a PoW Company were those classed as unfit (previously wounded, older, had a current medical issue etc etc) for front line duties - and previously served in an infantry unit. You should try investigating your man, as having served in one of the Guards Regiments. He would almost certainly have received his medals as serving with 203 PoW Coy - and may even have been invalided out. Look for a Silver War Badge (SWB) in his name.