What makes a really successful house purchase? It's one where the house not only increases in value but also makes you feel great every day you live in it. If all you eventually get out of the deal is money, you're missing half the reward.

A feel-great house fits your lifestyle; its colors ebb and flow through interior space in a calming fashion; the room shapes and openings have a logic that makes furniture arranging easy, and it still looks good five years after you bought it -- even if that time brings a couple of more children and a dog into the household.

So how do you end up with a house that is a win-win both financially and personally? Engage some expertise in the "make my house work for me" department. If you are working with an architect, he or she will tailor the house to you. But if you're working with a custom home builder or buying a new house from a production home builder, consider bringing in an interior designer who specializes in residential work.

Such a person is skilled in massaging and matching a house to a lifestyle, has a practical streak, and has expertise in the aesthetic nuances and durability of materials and finishes that goes far beyond that of a typical model salesperson and most custom builders.

Arrange for a consultation with an interior designer in your current house, and he or she can make some quick and helpful observations that might lead you to redirect your housing search. For example, if the personal style projected in your smallish rooms is one of cozy comfort, the designer is likely to suggest -- tactfully of course -- that you might not be happy in the great big house with big rooms that you have set your heart on. A house that's only somewhat bigger might be a better fit because it's hard to have an intimate conversation or a small, friendly, informal dinner party in a breakfast area that's big enough to seat 12, and it's hard to feel cozy next to a fireplace that's in the middle of a 20-foot-long wall.

When you've narrowed your search to a final two or three models, an interior designer can help you decide which house and which options are right for you. Someone who has merchandised furnished models for home builders can be especially helpful because she will have had experience in furnishing production-built houses -- and know some of the pitfalls.

For example, a sunroom that looks great in a model home can often turn the adjacent living room into a "drive-through" space with no sofa wall and no way to arrange the generous three-person sofa and overstuffed arm chairs that many people want to put there, said Carlyn Guarnieri, an interior designer who works with home builders in the Washington market and has worked with individuals in the past.

Matching the house to a household might also include finding alternate uses for conventional rooms. If the house has a living room that Guarnieri knows the owners will never use as a formal sitting area, she helps them figure out how to make it a functional space for their lifestyle. For example, if the household will always be in the family room area at the back of the house, the living room at the front could be used as a home office or an adult lounge with a pool table by adding French doors.

Once you've settled on the house and start dealing with specific colors and finishes, an interior designer can help you select these in a sensible manner. Many clients want to start with specifics such as the dining room chandelier, Guarnieri said, but that's like starting with the icing instead of the cake. You need to nail down the overall look first, she said.

For example, when a house has an open plan -- that is, you can see the formal areas, kitchen and family room "in one eyeful" from the front door -- you'll end up with a visual mishmash if you don't determine an overall color scheme, Guarnieri said. With all those rooms, many people want to put every color in the rainbow in there, but you need to limit yourself to only three or four in varying proportions to create a pleasing overall panorama and a nice "flow" as you pass from room to room. You might draw colors from your current furnishings or start fresh with a completely new palette, but this will be more expensive as it will entail new slip covers or reupholstering or replacing the furniture you have now, Guarnieri added.

Every room does not have to have the same color theme, however. In your "closed rooms" -- bedrooms and a home office that will be closed off from the general view -- you can be more freewheeling in your color choices, Guarnieri said. This can even be practical. A home office that markedly differs from the rest of the house in color and style reinforces the fact that this is a space for serious endeavor, not wastepaper basketball.

When you're finally ready to weigh in on specifics, an interior designer can be especially helpful in sorting out the distinctions and nuances among the multitude of choices in cabinetry, countertops, faucets and flooring that most builders offer. It's easy to get overwhelmed and lose sight of their durability and cleanability -- critical characteristics that should guide your choices, said Ann Arbor, Mich., interior designer Jane Hughes, who for the last 40 years has worked with families buying production-built houses.

Moreover, she added, the requisite degree of durability varies with each household, depending on whether it has teenagers, young children or no children at all.

In some instances, Hughes may recommend bypassing the builder's offerings altogether to get something more durable. For households with very small children, she likes a commercial grade of carpet because it's manufactured to withstand more abuse than children could ever inflict.

Eventually you will get to the icing on the cake -- the lighting. Some guidance at this point can be especially helpful because each type of lighting fixture creates a different mood that can range from "dramatic" to "conversational" to "focused on calculus homework, don't talk to me," Hughes said. Many of these effects can be created with freestanding lamps or torchieres, but the ones to address initially are those that the builder will be installing.

To light those walls where you plan to hang artwork and want some drama, Hughes specifies a recessed "eyeball." For food-prep activities such as chopping vegetables that require focused light on a kitchen counter, she specifies xenon fixtures mounted in the recess under the wall cabinets. For general lighting in the family room, especially if you have small children and don't want them tripping over electric cords, Hughes recommends wall sconces because they give better quality of light than the recessed ceiling fixtures that home builders typically offer. But Hughes does like recessed ceiling fixtures for hallways, stairs and transitional areas where you move from one kind of flooring to another.

One spot where almost no one thinks about the lighting is the linen closet, Hughes said. She always addresses it because inadequate lighting can make it irksomely impossible to distinguish common sheet and towel colors of similar hue and intensity, such as sky blue and lime green.

Contact Katherine Salant at www.katherinesalant.com.

(c) 2005, Katherine Salant

Distributed by Inman News Features

Garish colors can make a room feel unsettled and cramped, such as this living and dining area, left. An interior designer can help match styles to color, right.