I see this as a Period 2 building.
If you have extensive surgery and hair grafts and knee replacements, has your date of birth changed? No. Get a brain transplant and then, perhaps, yes.
Feng shui is an old and virtually scientific thing which includes a variety of different (and sometimes arguing) schools. And then there is the contemporary, watered down diy version. Even Masters from the same general method will disagree. What fun
I have found real long term benefits from a classical approach. Few benefits from the modern diluted and New Age influenced approach
So to get the best results, yes you need a very accurate floor plan (if you get the location of the doors wrong your info is seriously flawed, if you place a "cure" in the wrong part of any sector, they will not work or will work poorly).
One thing that can be quite challenging -- although people don't often realize it -- is getting the compass direction perfectly accurate. In some houses "close enough" is good enough. In others, a degree one way or the other changes everything!
If you get the floorplan and the direction right, then once you understand fs deeply you will be able to predict future occurrences and perhaps take steps to prepare for them or benefit from them. As you begin to learn, do not be frightened by the dire predictions that will pop up (Sickness! Accident! Cheating spouse!) Activating these potentialities requires specific triggers and a bazi chart that agrees with the prediction. So more often than not, those bad things do not occur (for example, I have the annual 5yellow and other bad sha at my front door this year. DISASTER! Nope, one of the best years ever

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