It's a cold morning, and you're ready for a hot shower. But it seems to take forever until the water warms up. If you have a very large home, then the culprit could be long pipe lengths between the water heater (usually in the basement) and the bathroom (master baths are usually on an upper floor). If you're having a home built, that's not a necessary evil -- talk to your builder about the plumbing system design to see what options you have. For example, a re-circulation pump or point source instantaneous unit might be options. While perhaps the least exciting system in the home, plumbing is an important part of a healthy home.

Plumbing includes all of the water supply and water waste lines. When the home's foundation is built, a plumber runs a supply line from the street through the foundation wall or the slab. From that point, they run the lines that supply water to the home to rooms where sinks, bathtubs, showers and other fixtures will be installed.

Copper piping is the traditional material most often used for water supply lines, although some plastic piping materials are gaining popularity and code approval. This diagram shows the path of the water to the fixtures, as well as the path for waste water from the fixtures through the drain waste vent pipes (DWV), and away from the home. The drain waste vent pipe is part of a home's plumbing system that is specifically used to carry waste water down and away from the home, and allows sewer gases to be pushed out through the roof. Drain waste vent pipes are typically plastic.

The plumbing system is required by code to keep the home's occupants safe, including:

• Automatic anti-scald feature at each shower fixture to keep water from getting too hot.
  
• Traps at each fixture to keep harmful sewer gases from leaking into the home. A trap is a curved section of plumbing pipe that seals the pipe to prevent sewer gas from getting into the home. It's also known as a p-trap. Traps also help prevent unwanted items, like hair or debris, or things that fall down the drain, like rings, from going down the drain and getting stuck in the waste system.
  
• Drain waste vent pipes to push out harmful sewer gases through the roof.
  
• As an additional health and safety measure, a specialized building code strictly regulates plumbing systems. A specialized plumbing inspector checks the installation when the pipes are being put in, and again when the home is finished -- right before closing -- to ensure all codes are followed and the plumbing is safe for the occupants.

The plumber also installs the gas lines in the home because the materials and tools needed are similar to those traditionally used for plumbing. Gas supply lines can be black iron or flexible stainless steel or flexible copper pipe. Gas is distributed through the home by a single pipeline that has other pipes branching from it, or by a manifold, which is a pipe with several outlets for supplying multiple pipes.

The plumbing system also includes the water heater. The most common types of water heaters are gas, electric, oil or propane. If you have a gas water heater, direct vented is most desirable. If that's not an option, the second choice is power vented. Direct vented and power assisted are terms that describe how gases generated by the water heater are released from your home, which is critical for you and your family's health. Direct and power vented gas hot water heaters are less susceptible to combustion gases flowing back into the home because they force combustion gases out of the house.

The efficiency of a water heater is measured by its Energy Factor (EF). Hot water tanks with an EF greater than 0.56 for gas-fired units and 0.88 for electric units are recommended. For an upgraded price, you may be able to choose a heat pump water heater or instantaneous water heater. These are more efficient water heaters. You should discuss the features and benefits of both with your builder.

If your home is very large, there may be long pipe lengths between the water heater and one or more of the bathrooms, causing a delay in the hot water getting to that bathroom. Ask your builder if this is the case in your home and what the delay might be. If it's more than you're willing to deal with, ask about installing a circulation system that can minimize the delay.

Remember, the choices you make regarding your plumbing system will help ensure your home performs the way you want it to, and that it's absolutely safe for you and your family. When your home is being designed, talk to your builder about:

• The hot water tank's storage capacity -- is it enough for your family?
  
• Whether there's an expansion tank for the water heater, which is a safety measure to prevent pipes from rupturing.
  
• What type of water heater will be installed in your home and how combustion gases are expelled from the home (it should be either direct or power vented).
  
• How efficient your water heater is.
  
• Whether a more efficient system like a heat pump water heater or instantaneous water heater is appropriate and what the additional costs would be.
  
• What kind of delay you can expect in each of the bathrooms and whether the builder can install a circulation system to minimize the delay.
  
• The locations of outdoor spigots, where you'll need to use a hose.

Get tips for increasing your home's value by updating your plumbing system at HGTV's FrontDoor.com.