Hi Jack, 

Tiler_Burden is English, so I'm not sure he'll be able to follow along and I'll reply in English. 

Anyway, I agree Tiler_Burden that an estage_agent ("makelaar") isn't the most fitting tag, I've switched it to office=property_management which also isn't an exact match, but based on the wiki descriptions of both, does seem to be the best choice for now. Please see these pages for more information:

https://wiki.openstreetmap.org/wiki/Tag:office%3Destate_agent
https://wiki.openstreetmap.org/wiki/Tag:office%3Dproperty_management

I've changed the tagging accordingly, the changeset can be found here:

https://www.openstreetmap.org/changeset/153301518

I will close this note as resolved, but feel free of course to reopen it if you have additional thoughts. 

Tiler_Burden: same goes if this wasn't the problem you tried to indicate. 

Cheers,
Roelant.