Isee 2024, how to remove a child with income from the family unit?

Isee 2024, is it possible to lower it by removing an adult child with his own income from the household? Now that we are dealing with the renewal of the ISEE, the problem for many families is that of losing the right to benefits and bonuses because, perhaps, they have an adult child who started working in 2022 producing their own income which adds up to that of other family members.
The first thought is to get the person out with the new family income to return to having the ISEE certificate with a relatively low value and to return to being entitled to many of the benefits provided by the State.
The case of the adult child who works, in any case, is the most emblematic one because in most cases, even though they do not contribute to the family's expenses, they raise the value of the ISEE with how much they earn.
How to ensure that children leave the family ISEE? read also How to get out of the family ISEE? How to get a child out of the family unit Let's take the example of a family made up of a disabled mother, a father on social security, a daughter who is a university student and a son who has his own job.
The son's income, added to that of the father, increases the value of the family ISEE, preventing the student from being able to benefit from benefits for the right to university study.
The best thing to be able to benefit from university benefits for the daughter and to perhaps give the mother the right to receive some form of subsidy (such as the inclusion allowance) would be to exclude the working son from the family unit for drastically lower the value of the ISEE.
This is an operation that is not always possible.
As long as the working child resides with the rest of the family, he will inevitably be part of the family unit and, consequently, will return his income to the ISEE.
The only way to ensure that the income of the boy, now economically independent, does not fall within the family ISEE, is to have him leave the family state.
That is, make him change residence.
If the child has the possibility, he could go and live alone, in this way his income would no longer affect the ISEE of the family of origin.
The adult child, alternatively, could take up residence with grandparents or other relatives as long as he does not harm their ISEE with his income.
Another possibility to allow the child to leave the family unit without changing residence could be to divide the family home into two separate apartments, with two independent entrances (but in this case the costs for carrying out the works could also be high based on how the house is structured) and divide the family unit into two distinct nuclei: father, mother and student daughter in one apartment and the son who works in the other.
But this must also be possible from a cadastral point of view and to understand if it is feasible it is necessary to contact an architect.