Sample Illustration Showing Unit #04 is the only one impacted by Sha Qi or Poison Arrow from the mosque spine emblem.
1. This simple illustration:-
2. Even if standing at the windows of unit #02, #03 may be able to catch a glimpse of the mosque's spine; fortunately, they are not impacted by it.
3. In the illustration, it is clear that unit #04 is situated at the same level as the mosque's spine. Therefore, this unit is considered to be affected by the spine.
4. It would be more challenging if the spine directly faces or is tangent to the living room windows - a difficult situation to remedy, as it would fully block the windows.
5. It would be simpler to address if the spine faces a bedroom window. For instance, a "permanent" day curtain could be installed and drawn at the bedroom window(s). The key is: "If it's not visible, it's no longer a threat."
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Therefore, even residents inside units like #05, #06, and above can see the mosque's spine (half moon + star crest) from their windows, but they are not affected by the Sha Qi (Poison arrow) of the spine.
Unit #04
Only Unit #04 is considered to be affect by the spine (logo) or tip of the mosque
Related:
Masjid [Mosque] Darul Ghufran
@ Tampines surrounded by HDB Tampines GreenSpring under construction