Remodel work is generally more time consuming and thus more expensive than new construction work. Refitting the remodel into the existing electrical system requires care and attention to detail. New electrical loads on the system must be considered so the existing circuits will not be overloaded. Often new circuits must be pulled through existing walls and structure meaning drywall will have to be patched. Sometimes, if the remodel is large, or if the electrical load is sizable (i.e. adding another kitchen, or more heating/air conditioning) the service must be upgraded.