Retrofit wire and cable installation is challenging. Depending upon the building structure, the geography and that date of construction, the building codes, materials used and construction standards may differ drastically. Furthermore, supposedly “consistent” modern construction techniques may present surprises inside the walls. Things like fire blocks, PVC conduits and plumbing, insulation, metal studs, existing wires and potential non-code modifications can make a retrofit installation a nightmare. Running wire in new construction is so much easier when you can see where you need to go and what lies in your path.