From the perspective of geomantic omen, will building a mound at home affect the decoration of the home?

It won't affect. First of all, you live in a mansion, and your ancestral grave is a mansion. Yin Zhai, as long as the people who rest in peace don't commit Yang Zhai, is like staying out of the river and living a peaceful life. The villa is inhabited, and if the numerology is properly matched with the pattern of the house, it will be impartial and stable, and only help each other!