Fully understanding the problems you have with the existing space in your house may be the biggest problem of all.

In deciding whether to remodel that space or to add on to it, people all too often leap to the idea of adding on to a house instead of first looking at the way they live. In part, we are bound by the stereotypes about the appropriateness of certain activities in traditional spaces. The family room, a popular choice for an addition, becomes a living room the kids can eat in, and the more formal living room is virtually abandoned, becoming merely the room friends walk through to get to the more informal, generally more airy new addition. And while it's nice to increase the size of your house, a family room addition may not be the answer.

The first criterion the house owner usually considers is cost. In the metropolitan Washington area, the cost for renovation of existing houses runs anywhere from $30 to $50 a square foot.If you are adding on, new construction runs about $50 to as much as you'd like to spend a square foot. In short, it's never cheap. If you're handy, there are a lot of things you can do to cut down on the cost, from doing all the work yourself to acting as a general contractor for the job. But these tasks take time and talent and can just as easily cost more if you don't know what you're doing.

Before the cost is considered, however, there is an essential question that needs to be asked: What's wrong with the arrangement of the house as it now stands? That question is not always easy to answer since each individual has a different set of requirements and dreams.

A good first step is to make a list of what you do and don't like about the house or the area you are considering altering. If you live with someone else, the next step is to try to work out the inevitable differences in perceptions. Architects and designers often recount stories of visits to couples who think they know what they want only to discover that their ideas are in conflict. It may pay you to sit down with an architect, designer or contractor and talk over your ideas about making changes, whether it means additional closet space or a new kitchen or family room. Paying a professional to work with the arrangement of spaces could save a lot of aggravation down the road. When hiring an architect, be familiar with his or her work ahead of time so you won't be surprised by the first proposed drawings.

The Randy Harris family knew they needed more kitchen space in their townhouse in the Foxhall Village section of Washington. They also knew that they didn't have a lot of money to spend on the project. With the help of the firm of Wiebenson Associates, the couple literally "blew out" the back of their house to add two much-needed bay windows, extending the space in the existing living room and reshaping the old kitchen dramatically. The Harrises actually added only about 80 square feet, but the arrangement of space and the addition of light changed the entire complexion of the house.In the living room, the alcove addition became a naturally lit seating area. In the kitchen, the actual size of the work area wasn't changed, but the arrangement of the appliances and the sink was altered to allow for an eating area with window seat, doing away with the hallway that once led to the back door. The effect is to open up the space between the living room and the cooking area and to make the closet-sized kitchen more efficient and pleasant to work in.

In the Capitol Hill house of architect Bill Morrison and his roommate Hugh Kelly, all the spaces were opened up by Morrison's clever use of dividers between rooms. On the first floor the kitchen is compactly designed to accommodate two cooks simultaneously, yet it is squeezed into a hallway beside a staircase. To keep the cooks from feeling cramped in that small space, the kitchen walls rise only as high as the upper cabinets, about 18 inches short of the ceiling. Several windows and doors open up the space in the narrow kitchen even more.

Upstairs, Morrison's talent for finding space where none seemed to exist is dramatically demonstrated. As in many mid-19th century houses in the area, the front portion of the house rises and then slopes down towards the back. Usually there is a kind of crawl space in the front and no attic to speak of in the rear of these townhouses. Morrison carved the second floor into three parts, with a central den between the two bedrooms that span the entire width of the house, and removed the ceiling in front to open the crawl space and create a two-story space over the front master bedroom. Atop the two-story bedroom, in what had been a dim, dark crawl space, Morrison installed a spacious loft office which is entered from the den by a ladder.

Sometimes, differences in one's sense of space can be achieved through rather subtle reshaping of spaces. In the two-bedroom Georgetown apartment of foreign service officer M. DeWitt, architect Hugh Newell Jacobsen made subtle changes that have had a dramatic effect. Jacobsen expanded by a foot the narrow, dark hallway that is characteristic of most row houses. He then added light by putting in two round skylights. All sharp right-angled walls were softened and rounded -- a cue picked up by the architect from the homeowner's favorite instrument, the cello. The rounded walls help lead one's eye around spaces and, instead of cutting off views, invite one to see what's around the bend. The theme extends to the entire apartment -- even the kitchen door is a convex shape and the doors in the bedroom closet are rounded. k

While Jacobsen recarved the rooms within DeWitt's apartment, Don Little was busy making a tiny two-bedroom house in Silver Spring into a creative, expansive space in which a young couple could raise a family. Little first reshaped the front entry, giving the front door a more distinguished appearance while adding light and an air-lock for energy efficiency. At the same time, he retained the dignity of the original look of the house. In the back of the house, the changes are far more dramatic. Little reshaped the entire second floor, adding a bedroom and expanding the existing space. Then, at the very rear of the house, he put in a warm, two-story space for eating and entertaining. In a humorous turn of tables, Little retained the dormer windows but set them on their side, making two dramatic diamond-shape openings at the rear of the house. The net effect of all the changes was to add about 760 square feet to the house and to improve its overall design to better meet the needs of the family.

Backyards are often neglected spaces that can be converted to useable outdoor living rooms. Sometimes the most efficient, practical addition is a simple deck. Architect Don Hawkins reshaped the interior of a Georgetown house so that the dining area and kitchen are one, and then opened up the entire back of the house with three sets of French doors opening onto a deck, making a wonderful viewing platform for a small garden. Privacy trellises were added to either end of the deck, and below the deck is adequate storage for all sorts of necessary garden gear.

Probably the biggest lesson one can learn in reshaping or altering spaces within a home is that thinking expansively does not always mean massive dollar signs and big additions -- sometimes it's the little things that count.