You've assessed the building using only Flying Stars. What is more powerful than Flying Stars is the Natural FORMS. Our environment. That's where Qi comes from. The FLying Stars is a beginnin assessment method. It main sees a "potential". But the REAL Qi comes from the natural external environment.
If the environment is positive, with "good" features, a property can have long prosperity despite the period luck. Likewise, if the environment is not good, then no matter how timely the Flying Stars are (including stars #8) can become negative. So the most important thing is to learn how to see the Forms.
By forms, I am refering to the way the environment works. And not just looking at the buildings to the left and right. We need to assess the quality of the mountains, contours, water formation and landform structure. This is called "Luan Tou" Feng Shui.
Warm Regards,
JY