It's a spa getaway, a calming retreat, a small slice of serenity where you can shut out the world and exhale. We're not talking about an exotic resort, here. The bathroom—that room with a toilet, bathtub, sink and shower—is an ideal space to create a happy place you can visit a few times each day without ever leaving your home.

In fact, the bathroom might be the only room in the house where you safely can lock yourself inside for a half-hour to escape the noise of life, stress of the day, and potentially the hubbub that's happening right outside that door (ahem, parents of small children).

That said, "bathroom" seems a misnomer for a space where such quality time can be spent. And beyond the master bath, there are functional family bathrooms—the full bath—and convenient three-quarter bath layouts with toilet-sink-shower amenities. The tiniest space of all, the powder room, or half bathroom, can be a pint-sized showcase of your personal style. And you can really play up the drama in a guest bath.

When it comes to the bathroom, there's a whole lot going on in a relatively small space. "Bathrooms are becoming so much more than a room that takes care of a function," says Brian Johnson, principal, Collaborative Design Architects, Billings, Mt. "I compare it to how a TV room has evolved into a home theater with surround sound."

Despite its importance, the bathroom is still often the smallest space in a home. "But the bathroom is the second most vital and expensive part of the house," Johnson says, noting that the kitchen is the largest investment. Johnson says most of his clients spend between $175 to $225 per square foot, and the cost of remodeling goes up from there depending on the appliances, fixtures and finishes you choose. Splurging for a flat-screen television that hides behind a two-way mirror? You'll pay for the luxury, but it could make your morning rush-hour in the bath feel less harried. Coffee makers, fireplaces and furniture are also finding their way into master baths. There are seemingly no limits.

There are certainly parameters to your budget and expectations for return-on-investment. That's where this Bathroom Planning Guide comes into play.

"We are finding with people's requirement for customization and ways to experience spa-like benefits in their home, they are willing to pay for those benefits if it increases the value of their home or if it contributes to their well-being," says Diana Schrage, senior designer for Kohler.

We'll help you set goals for your bathroom remodel, personalize the space to suit your needs and inspire you with designs that appeal to all tastes. With any bathroom remodel, budgeting and space planning are critical first steps: developing a financial plan and a design blueprint for the bathroom. Learn how to deal with ventilation, conserve water, organize the layout and make decisions on the vast array of fixtures. We'll walk you through the process step-by-step in this guide.