Basic bathroom remodeling - an important way to improve your home

Bathroom remodeling continues to rank second only to kitchen remodeling as countless thousands of Americans determine to ''stay put'' in an economy that stifles new-home construction.

Remodeling companies and do-it-yourself homeowners alike are behind the surge to upgrade existing baths and make them more attractive as well as more functional for the modern family.

Just like planning a new bathroom, remodeling an existing bath begins with a determination of the desired floor plan.

Often this decision will be made for you for the most part by the amount of space available, but if you are adding on to your home, you can begin from scratch and enjoy a wide latitude in design and layout.

Before buying new fixtures and materials, take a pencil in hand and jot down a few answers to such questions as:

* What area of my home will be served by this new bathroom?

* Who will be the principal users of the bath - parents, children, guests?

* Will this bathroom be an integral part of the master suite, or should it be ''family'' in nature to serve several nearby bedrooms?

* How much space can be allotted to the new bath?

* What is the ''outside'' cost figure that can be considered?

* What basic fixtures are ''musts'' in the new or remodeled room? Tub or shower?

* How much space should be set aside for storage?

* Will the room be used for other than normal bathroom purposes, such as an added place to relax, an exercise room, or an extension of the master bedroom suite?

Your answers will lead you to other necessary determinations, including basic placement of the major fixtures - tub-shower, lavatory, toilet (bidet) - which cannot be as easily changed the way you might move furniture around in another room in your home.

On the other hand, if you are remodeling an existing room, don't fail to consider actually moving the existing fixtures if they now cause an every-morning bottleneck or are so badly outdated that they make this a room where you always want the door closed to keep it out of sight.

New fixtures on the market provide a wide range of shapes and sizes from which to choose.

The old tub on cast-iron feet is still in vogue, but it's now offered in sparkling colors with highly decorative fittings.

The new lavatory bowls can be set into more serviceable countertops without the need for framing rings to hold them in place. Toilet designs are many, including units for cramped areas, units that will fit into the triangle of a corner, one-piece units that combine the tank and bowl in low silhouette, and units that flush silently and can't be heard running in other parts of the home.

While the most economical plumbing arrangement incorporates all fixtures on a single wall, this greatly reduces the design and use acceptability of the room and is often thereby discarded in favor of using one or more additional so-called ''wet'' walls.

Many manufacturers of fixtures offer booklets containing suggested layouts that will further spark your imagination.

Compartmentalizing a bathroom permits more than one person to use the facility in privacy. This is accomplished by means of a sliding or swinging door that closes off the tub-toilet area from the lavatory area; the tub-shower area from the remainder of the room; the toilet area from the bathing-grooming section.

Use of a tub section between two areas equipped with lavatories and toilets can be an economical means of handling teen-age rushes that have been known to get people off on the wrong feet in the morning.

Use of a tub section between two areas equipped with lavatories and toilets can be an economical means of handling teen-age rushes that have been known to get people ;off on the wrong feet in the morning.

From an adult standpoint, when remodeling an existing bath, take a careful look at the possibility of removing the exterior wall and opening the room onto a private patio or garden area.

A sliding glass door, for example, will provide easy access to a whirlpool bath or just a simple place to relax in the sun or a flowered area to enjoy from inside or outside the room.

Just as today's bathroom is ''miles'' ahead of the first such room, built more than 4,000 years ago in the Cretan city of Cnossus, today's bathroom remodeling can accomplish so much if only you prepare yourself well in advance of picking up the necessary workman's tools.