In short, the real property qualification and the fact that senators have a non-renewable appointment — they were originally appointed for life — were meant to render the upper chamber independent of the Crown and served as well to place the upper house on a different footing from the lower house.
Somme toute, la qualification foncière et la nomination irrévocable des sénateurs — qui, à l'époque, était de surcroît viagère à l'origine —, devaient assurer l'indépendance de la Chambre haute face à la Couronne et la placer aussi sur un pied différent de celui de la Chambre basse.