Utilities

Inform your service professional about the relocation of utilities. For instance, bringing in plumbing, electricity or a gas or phone line may necessitate wall or structural changes. It will also let him/her know if a subcontractor will be necessary to help complete the project.

Outlets and Switches

There has been something of a design renaissance in light switches. New switches offer a wide array of features like full-range dimming, a delayed fade from on to off, dimmers that remember a range of settings, switches that automatically turn lights on when a person enters a room, central lighting controls that operate lights anywhere in the house and even, hand-held infrared remotes.

Make sure you have enough outlets and switches to run every electrical appliance you have. It's also not a bad idea to add extra of each for future appliance additions.

Heating

There are many options to consider with heating. You can simply link the addition to your existing heating system, or you can install a separate system.

Radiant Heating

If you choose radiant in-floor heating, which uses hot water to heat your floors, your service professional may need to enlist a plumber. Electric baseboard heat may require an electrician.

Forced-Air

A forced-air heating system draws the air from the room through ductwork to a furnace, where the air is filtered and heated. Most manufacturers make several sizes of each model. These furnaces come in "upflow," "downflow" and "horizontal" models designed to accommodate basement, attic or limited-space installation. A forced-air system can be combined with an air-conditioning unit, a humidifier and an air filter.

Electric Heat

In most areas, electric heat is best reserved for specialized applications, such as heating an added-on room, temporarily warming a bathroom, or heating a home where other more affordable fuels are not available.

Rental Unit

If you're adding a rental unit, you might want new electrical service for the addition to separate your usage from your renter's. Or you might want to add a new sub-panel, a smaller panel that has its own set of circuit breakers leading to household circuits and located in a different part of the house than the main panel.

-- Tips courtesy of HomeAdvisor.com