For wiring in a house, the two considerations are involved :
(i) cost of metal wire used. (ii) Good conductivity of metal wire.
The silver wire has the best conductivity but it can not be used due to its high cost. After silver, the copper and aluminium are the next best conductors. their cost is also low than silver. Therefore copper and aluminium are used for wiring in the house.
Conductivity of copper wire is more than that of aluminium wire and for a given area and length, the mass of copper wire is more that taht of aluminium wire. Therefore, if we require better conductivity without considering the cost involved, then copper wire is preferred. If we keep in mind the cost factor involved in the wiring, then aluminium wire is preferred.
