You can clearly see the arrangement of the ‘wijken’ perpendicular to the Northern- and Southern-canals (vertical on the right) and the Drachtstervaart horizontally in the middle. My grandparents lived in the Oosterstraat, one block north of the Drachtstervaart, and just to the right of the main street in the middle (right click on the map to open in new tab and enlarge)
Opa did have an office in the house, but his real office might have been at #8, which is labelled ‘Kantoor Rijksontvanger’ (Tax Collectors Office) in a legend I found on the site of Oud Drachten, another site with lots of images and maps of Drachten. Fun to explore.
(1) Today I found the same picture on the Oud Drachten site, so it was not really his property.