Big houses consume more resources than small ones. They use more wood, more carpet, more drywall and more concrete. They cover more ground and generate more construction debris. When completed, they will require more energy to heat and cool.

A house's size has a greater impact on energy and resource use than any other factor, including insulation, equipment efficiency and windows.

"Building small makes 'natural sense.'" says Duo Dickinson, a Connecticut architect and author. "First, you build what's needed and then what's wanted. The problem is that many people don't know the difference."

It would be impossible to get universal agreement on how "small" a small house should be. Prison cells are small, but hardly livable. "For the designer, the key is to make the house fit the clients," says Dickinson. "A house fits when living in it is effortless." Like a tailor fitting a garment to the exact dimensions of a human form, a designer should strive to size building elements for the occupants' values and way of living.

Spec homes can benefit from many of these ideas, too, although the house may not achieve the same level of space efficiency. By using design savvy, instead of adding space, a spec builder can make a house feel better, work better and sell faster.

Space Design Savvy Tips

Smaller is often better, but actually cutting square feet out of a house plan can be difficult. Here are a few ideas that can help. You may find that several of these ideas can be used in a given plan, although you certainly wouldn't use them all at the same time.

Share space between different uses. A home office and guest bedroom is a common combination. Also consider using a hall or stairway as a library or gallery, a landing can be a reading nook, the laundry can be a mudroom. Replace individual rooms for "media," exercise and others purposes with built-ins and storage for special equipment.

Add double-height space. Smaller rooms need not feel "cramped." High vertical spaces add an airy feeling.

Fill the entire building volume. Much usable space can be lost to attics. This space under the roof can be used for visual appeal, loft space or heated storage. Cathedral roof trusses with ceiling insulation, stick framing with insulation between the rafters or structural insulated panels can all provide full insulation while embracing the volume under the roof.

Reduce circulation paths. Shorten or eliminate hallways, unless they serve a dual purpose. Traffic patterns can cross rooms, so the extra space adds to the visual size of the room.

Build furniture into rooms. Cabinets, bookcases, benches and eating nooks use less space when they become part of the structure. Recess bookcases or display cases into interior walls. Large storage drawers can be installed under the stairs right down to floor level.

Remove formal spaces. Most people gather in kitchens and family rooms. Formal living and dining rooms are seldom used. So why have two spaces dedicated to essentially the same activity? Avoid showcase rooms.

Use bedrooms for sleeping. In a small house, the bedrooms should be used for sleeping, dressing and little more. Massive "sanctuary" bedroom suites, some as large as entire homes, are wasted space.

Provide ample storage. When people want a "bigger house" they may actually need more storage. Even if a house is small, careful planning and good organization can provide densely packed, three-dimensional storage.

Enhance trim and detail. High-quality details can be a key benefit of a small house. High-quality hardware, moulding and other aesthetic touches can draw attention away from the larger space and to the details.

Add a focal point. Each room should have one attractive feature. This can be a building element, built-in furniture, a work of art or a dazzling light fixture.

Invite natural light. Careful selection, sizing and location of windows and small skylights can flood a small space with natural light without increasing energy use. Artificial light works, too, if it's carefully designed.

Bring in the outdoors. Locate windows and glazed doors next to decks, patios, courtyards and porches. This extends the living space past the outer walls during fair weather. Even during bad weather the visual extension continues.

Reveal the structure. Exposed beams, posts, joists and other structural elements can define individual areas within a larger space. They also add texture or interest, and can serve as a focal point. Be careful, this approach can also be distracting. Use color. Most small spaces will benefit from lighter-colored or white wall paint, because it gives a spacious feeling. Use dark or warm colors only for accent.

Tie spaces together. Similar materials, such as flooring, wall coverings and trim, tie spaces together visually, giving the overall impression of greater space.

Separate spaces. Dissimilar materials set one space off from another. Instead of building a wall, change floor coverings, expose a beam or a hang a pot rack. Changes in color and texture also define spaces.

Be playful and imaginative. Examine the occupant's personality to find a fun or humorous touch that can set the space apart.

Plan for flexibility. The design should allow for changes in lifestyle. A young couple may have children. Grown children will leave the nest. A business could be born in the kitchen and grow in the guest bedroom. Plan for these changes. Identifying a future addition is one way, but consider ways new uses could be accommodated inside the existing footprint. The upstairs could become an apartment for an aging relative. Walls could come down. Some designers suggest long-span structures so that interior walls can be repositioned with fewer structural limitations.

While there has been growing interest in environmentally friendly construction, it seems that many of these projects are just too big. On the other hand, there is a smaller countertrend. Some architects and builders see smaller homes as a benefit. Smaller homes are challenging to design, but often more rewarding.

A high ceiling, large mirror and plenty of natural light make a modest bathroom feel spacious.

Several books on small house design are available from Iris Communications, Inc. by calling 800-346-0104 or placing orders through the online catalog.

One obstacle for designers, builders and potential buyers of small houses is the way house size is described. Houses are measured, value is appraised, taxes assessed, fees charged, and permits based on floor area. This approach ignores the quality of the space and how it may feel. In his book, Small Houses for the Next Century, architect Duo Dickinson, offers another way of comparing house size based on "perceptual space." In order to use perceptual space to compare the "size" of different plans, Dickinson calculates three additional factors:

Axes

Axes are linear spaces with uninterrupted views through other spaces. The beginning and end is defined by a building element, such as a door, window, fireplace or stair.

Double-height spaces have walls at least 10 ft. high before any sloped ceiling plane begins. In a cathedral ceiling, this would be the minimum ceiling height. To calculate double height space, multiply the actual width by the length from floor level across the space to the top of the wall.

Defined spaces are unheated spaces that can be seen from within the house, such as decks. patios and balconies. Because these areas are used only during fair weather, divide the area in half.

Dickinson presents his own house as an example of enhanced perceptual space. The nominal floor area is 1,100 sq. ft. Axes add 313 sq. ft., double-height spaces add 300 sq. ft. and defined space adds 76 sq. ft., bringing the total perceptual space to 1,789 sq. ft.

In addition to perceived square footage, two ratios are useful when describing the living efficiency of a plan. First, add up the area dedicated solely to circulation and divide by the total floor area. Areas that serve as perceived space to any room are not counted. Second, add the floor area of all bedrooms and divide by the total area. Lower numbers reflect better fit for both circulation-to-total-area and bedrooms-to-total-area ratios.