In reply to Jonathan.
Hi Jonathan,
The original store room for J & D’s Executive Apartment was not a structural wall – their home’s layout is also slightly different from the example floorplan we shared in the article.
Nonetheless, J & D informed us that even though it is not a structural wall, they still had to obtain HDB approval for all the walls they wanted to hack, including the curved wall (arch) at the dining area.
Hope this helps!