Regardless of how these arrangements are structured, there will always be estate planning considerations to take into account. If a secondary home is being transferred to an adult child, a will or living trust may need to be updated to address the arrangement. Any loan created between parent and child is considered an asset of the estate and should be addressed accordingly.
If multiple children will eventually inherit the estate, how will assisting one child affect the inheritance of other children, assuming any estate plan created has an objective calling for an equal distribution of wealth among heirs? Should time be spent upfront discussing how giving or loaning money might affect family dynamics and planning?
There is no right or wrong answer in how to structure a legacy plan, but a matter of preference, and that any plan to gift or transfer property should be addressed in the context of a larger financial and estate plan.