The least-expensive bathroom projects usually involve some paint or wall paper, a new vanity and sink, flooring and new lights. The most you'll likely do is pull out the old fixtures and replace them with new ones. But what if the room isn't laid out for the most efficient use? The toilet works better in that corner. And how about a double sink instead of a single one? Now you're getting into some major work that involves moving some pipes in 94139, California.

You'll want to have a plumber involved in any bathroom renovation, whether to replace the faucet or to move drains. You can find a certified plumber for your area by clicking on the Find a Contractor link on the home page. Before you hire someone to do the work, though, be absolutely certain about your changes. It'll be twice as expensive to have the plumber come back and redo the work he already did.

A big issue for bathrooms is water pressure. No one wants to be standing in the shower ready to rinse off and all of a sudden the water reduces to a trickle. The standard water pipes for homes are ½-inch. Any obstruction along the way - buildup in the pipes, bends, distance - reduces your water pressure. If you're replacing pipes, ask the plumber to use ¾-inch piping. That should keep the water pressure up no matter how many faucets are in use.

Your plumber will be involved in many aspects of your bathroom renovation. He'll install new fixtures, move pipes and drains, set new toilets or add a shower head or massage jets in your new shower.