If your fate determines that you are lucky, the new house you built naturally conforms to the principle of Feng Shui without inviting Mr. Feng Shui. Inviting Mr. Feng Shui is the icing on the cake.
If your fate determines that you are going downhill, if you don't invite Mr. Feng Shui, there will naturally be many problems in the new house you build, which runs counter to the principle of Feng Shui. Even if Mr. Feng Shui is invited, you may not be the real Mr. Feng Shui, or the problems of the house you built cannot be adjusted, and the Feng Shui master can't do anything about it.