The cost to rewire a house ranges from $8,000 for 1,500 square feet to $15,000 for 3,000 square feet as of 2014. The actual cost depends on the amount and condition of old wiring, the age and size of the home, the amount of material that must be cut or removed, and the hourly rate for the electrician. Unexpected obstructions and residential code requirements can increase the price.
A home may need rewired if it was constructed more than 50 years ago, if residents smell burning odors or hear crackling from inside the walls, if outlets and switches appear burned or discolored, if circuit breakers trip frequently, or if fuses blow often. During rewiring, an electrician tears out old copper and aluminum wires and replaces them with a plastic-coated alternative. This replacement reduces the risk of a house fire, which affects nearly 26,000 U.S. homes each year.
Houses built between 1880 and 1939 often have knob and tube wiring, which provides air flow between wires and lumber through the use of ceramic tubes and knobs. Homes constructed between 1922 and the 1960 may feature cables insulated with rubber or PVC. During the 1960s and 1970s, builders placed aluminum wiring inside homes. Modern standards require non-metallic cables sheathed in thermoplastic insulation.