Considering a bathroom's complexity, it's little wonder that even the best-planned remodels can go awry. Readers had more problems with bath projects than any other kind, according to a recent Consumer Reports Annual Questionnaire.

Here's how to sidestep slip-ups:

Don't change your mind. Homeowners who changed plans after the job was started were much more likely to suffer significant cost overruns and delays.

Don't overcrowd. You know the scenario: The door bangs into the toilet, your knees rub the tub, and the shower door grazes the vanity. The National Kitchen & Bath Association, a trade group, suggests at least 30 inches of space between the front of any fixture and an opposite fixture or wall. That equates to at least 35 square feet for a bathroom with a tub/shower, toilet, and single-sink vanity.

Ventilate adequately. Bath fans should supply at least 1 cubic foot per minute (cfm) of air for every square foot of space. While one 50-cfm fan should be adequate for a bathroom 50 square feet or less, two fans--one for the shower area, one near the toilet--are better for spaces larger than 100 square feet.

Be sure there's enough light. Baths need overall lighting and task lighting around grooming areas. Lights flanking the medicine cabinet or mirror reduce shadows, while frosted shades cut glare. Lights in showers should be watertight; consider a combined fan/light there.

Make it safe. Water and slick surfaces make bathrooms a risky place. Floors, shower areas, and tubs should have slip-resistant finishes; add rubber mats or stick-on strips, if needed. Choose rounded countertop edges and corners over sharp ones. Also be sure to mount grab bars in tub and shower areas.